taxonID	type	description	language	source
0075879CFFBDFF83FF0982F34597FEA0.taxon	description	Figure 2	en	Maggioni, Tamara, Rimondino, Clara, Taverna, Anabela, Reyna, Paola, Lagger, Cristian, Alurralde, Gastón, Calcagno, Emilia, Tatián, Marcos (2022): Abyssal ascidians (Chordata, Tunicata) from the Weddell Sea, Antarctica, including a new Styela species and stomach content identifications. Zootaxa 5093 (3): 296-314, DOI: https://doi.org/10.11646/zootaxa.5093.3.2
0075879CFFBDFF83FF0982F34597FEA0.taxon	materials_examined	Material examined: 61 ° 45 ’ S, 47 ° 7 ’ W, station 16, 1180 m, 20 March 2005, one specimen; 61 ° 48 ’ S, 47 ° 28 ’ W, 2000 m, 20 March 2005, three specimens.	en	Maggioni, Tamara, Rimondino, Clara, Taverna, Anabela, Reyna, Paola, Lagger, Cristian, Alurralde, Gastón, Calcagno, Emilia, Tatián, Marcos (2022): Abyssal ascidians (Chordata, Tunicata) from the Weddell Sea, Antarctica, including a new Styela species and stomach content identifications. Zootaxa 5093 (3): 296-314, DOI: https://doi.org/10.11646/zootaxa.5093.3.2
0075879CFFBDFF83FF0982F34597FEA0.taxon	description	Description. All colonies have a transparent tunic, free of epibionts or encrusted external material. Both, head and peduncle of the smallest specimen measure two cm in height. The remaining three specimens present heads that measure on average five cm and peduncles of 8.5 to 11.1 cm. Zooids are arranged in oblique rows at the lateral sides of the heads. On average, zooids are 12 mm in length. Thorax and abdomen have the same length. The oral and atrial siphons have six weakly marked lobes. The dorsal tubercle is rounded. It is partially covered by a thick, circular and undulated pre-pharyngeal band. There are, on average, 14 oral tentacles. These become thicker and longer toward the dorsal side. There are two transverse vessels connected to each other by a short longitudinal vessel on each side of the body. In the zone of union with the mantle, each transverse vessel develops a prominent triangular languet. In contrast with the description of the type material, the musculature of the zooids extends down to the level of the stomach. The vascular appendix is long and thin. The abdomen has 12 folds. The gonads are in the abdomen, inside the gut-loop. The sperm duct runs parallel to the rectum. No larvae were observed.	en	Maggioni, Tamara, Rimondino, Clara, Taverna, Anabela, Reyna, Paola, Lagger, Cristian, Alurralde, Gastón, Calcagno, Emilia, Tatián, Marcos (2022): Abyssal ascidians (Chordata, Tunicata) from the Weddell Sea, Antarctica, including a new Styela species and stomach content identifications. Zootaxa 5093 (3): 296-314, DOI: https://doi.org/10.11646/zootaxa.5093.3.2
0075879CFFBDFF83FF0982F34597FEA0.taxon	discussion	Remarks. Despite being a frequent species in Antarctic and Sub-antarctic areas, this is the first record of Protoholozoa pedunculata in the Weddell Sea. There are only five species included in the genus Protholozoa, being P. pedunculata the most frequently reported species. The number of transverse vessels has been proposed to distinguish among species of the genus (Sanamyan K. & Sanamyan N. 2002): P. pedunculata and P. anthos Monniot C. & Monniot F., 1991 have two; P. pigra Monniot F., 1974 and P. incrustans Monniot F., 2021 have three; P. australiensis Kott, 1992 has four.	en	Maggioni, Tamara, Rimondino, Clara, Taverna, Anabela, Reyna, Paola, Lagger, Cristian, Alurralde, Gastón, Calcagno, Emilia, Tatián, Marcos (2022): Abyssal ascidians (Chordata, Tunicata) from the Weddell Sea, Antarctica, including a new Styela species and stomach content identifications. Zootaxa 5093 (3): 296-314, DOI: https://doi.org/10.11646/zootaxa.5093.3.2
0075879CFFBAFF82FF09804E4083FD14.taxon	description	Figure 3	en	Maggioni, Tamara, Rimondino, Clara, Taverna, Anabela, Reyna, Paola, Lagger, Cristian, Alurralde, Gastón, Calcagno, Emilia, Tatián, Marcos (2022): Abyssal ascidians (Chordata, Tunicata) from the Weddell Sea, Antarctica, including a new Styela species and stomach content identifications. Zootaxa 5093 (3): 296-314, DOI: https://doi.org/10.11646/zootaxa.5093.3.2
0075879CFFBAFF82FF09804E4083FD14.taxon	materials_examined	Material examined: 68 ° 32 ’ S, 20 ° 24 ’ W, station 9, 4930 m, 27 Feb 2005, one specimen.	en	Maggioni, Tamara, Rimondino, Clara, Taverna, Anabela, Reyna, Paola, Lagger, Cristian, Alurralde, Gastón, Calcagno, Emilia, Tatián, Marcos (2022): Abyssal ascidians (Chordata, Tunicata) from the Weddell Sea, Antarctica, including a new Styela species and stomach content identifications. Zootaxa 5093 (3): 296-314, DOI: https://doi.org/10.11646/zootaxa.5093.3.2
0075879CFFBAFF82FF09804E4083FD14.taxon	description	Description. The body of the specimen measures 7.5 cm high and 2 cm wide. The peduncle measures 5 cm in length. Its diameter remains constant until half of its extension, where it widens slightly until reaching the base. The base of the peduncle does not have rests of sediment nor tunic projections, probably because it was anchored to hard substratum. The tunic is transparent, thin and completely free of epibionts and exogenous material. Its consistency is extremely feeble. Both apertures are on the same side of the animal. The oral aperture is located a short distance from the peduncle. The atrial aperture is located approximately half-distance between the peduncle and the posterior region (Fig. 3 A). The oral tentacles are long and filiform. In total, there are 104 oral tentacles, of two alternate sizes, disposed in a circle. The pre-pharyngeal band is circular, with smooth borders. It is composed of two lamellae. With a short “ V ” it surrounds a “ C ” - shaped dorsal tubercle (Fig. 3 B). The dorsal lamina is composed of triangular languets. Strong muscular bands run through the dorsal region, from the oral to the atrial aperture. They extend from the medial dorsal region until ⅓ of the body, ending abruptly. Thinner circular muscles are distributed around both apertures. Transverse rows of branchial spiral stigmata, each with two to three coils, extend along the body axis. There are approximately 49 transverse rows on the left side and 45 on the right side. Each stigmata is crossed by two to four thin radial vessels. T-shaped papillae arise from the transverse vessels, most commonly at the intersection between stigmata. Some also arise at a mid-distance from a stigma. In some regions of the branchial sac, these papillae give support to longitudinal vessels. When present, there are one or two longitudinal vessels per stigmata (Fig. 3 C). In total, there are 73 longitudinal vessels on the right side of the branchial sac and 80 on the left side. The gut-loop is under the branchial sac, displaced to the right side of the body. The small barrel-shaped stomach has 20 longitudinal folds. The rectum runs parallel to the dorsal lamina and to the gonoducts, whose openings lie next to the anus. The anal border is smooth. Testis follicles and ovaries are distributed in the gut-loop, the former being spread over the proximal end of the former. Stomach contents. No items were found in this specimen.	en	Maggioni, Tamara, Rimondino, Clara, Taverna, Anabela, Reyna, Paola, Lagger, Cristian, Alurralde, Gastón, Calcagno, Emilia, Tatián, Marcos (2022): Abyssal ascidians (Chordata, Tunicata) from the Weddell Sea, Antarctica, including a new Styela species and stomach content identifications. Zootaxa 5093 (3): 296-314, DOI: https://doi.org/10.11646/zootaxa.5093.3.2
0075879CFFBAFF82FF09804E4083FD14.taxon	discussion	Remarks. This is the first record of Corynascidia suhmi in the Weddell Sea. Based on the revision of specimens of Corynascidia suhmi from the southern hemisphere reported by Kott (1969) and Millar (1988) and the specimens from the North Atlantic reported by Hartmeyer (1924), Monniot C. & Monniot F. (1994) considered two different specific entities. The authors proposed for the northern populations a new species: Corynascidia hartmeyeri Monniot C. & Monniot F., 1994. The characters that would differentiate C. hartmeyeri are: a plain dorsal lamina, less longitudinal vessels per spiral stigmata and a smooth-bordered anus. New material collected in the North Atlantic (Sanamyan K. & Sanamyan N. 2005) and in the SW Atlantic oceans (Sanamyan K. & Sanamyan N. 2002) allowed the latter authors to question the existence of C. hartmeyeri. They considered erroneous the observations about the dorsal lamina and the anal border performed by Monniot C. & Monniot F. (1994). We decided not to maintain C. hartmeyeri as a separate species nor to consider it a synonym of C. suhmi until the original material is reexamined or new evidence is found. Sanamyan K. & Sanamyan N. (2005) suggested three characters to differentiate between Corynascidia suhmi populations from the northern and southern hemispheres. One of them, (the number of transverse vessels) is not considered, because it might be associated with animal growth. Our specimen possesses one of the characters signaled by these authors for the southern hemisphere populations (shape of the pre-pharyngeal band). The remaining character (number of longitudinal vessels or papillae), coincides partially with what has already been described for those populations. As signaled by Sanamyan K. & Sanamyan N. (2005), more samples are required to definitively confirm this hypothesis. Based on molecular data, Monniot F. et al. (2011) found that specimens of Corella eumyota Traustedt, 1882 from Adelie Land, Antarctica, were in fact closer, with 93.75 % similarity, to the specimens of Corynascidia suhmi from the same place than to any other sequence of specimens of the same genus (Corella spp.) or even species (C. eumyota). Alurralde et al. (2018) confirmed those findings with phylogenetic analysis. Although the finding of Monniot F. et al. (2011) might most probably be the result of an incorrect identification or mixed sequencing, it only stresses the need to reevaluate the taxonomic status of the genus Corynascidia, since it might be possible that the morphological differences observed are only a product of adaptations of Corella spp. to the deep-sea, as was stated by Van Name (1945).	en	Maggioni, Tamara, Rimondino, Clara, Taverna, Anabela, Reyna, Paola, Lagger, Cristian, Alurralde, Gastón, Calcagno, Emilia, Tatián, Marcos (2022): Abyssal ascidians (Chordata, Tunicata) from the Weddell Sea, Antarctica, including a new Styela species and stomach content identifications. Zootaxa 5093 (3): 296-314, DOI: https://doi.org/10.11646/zootaxa.5093.3.2
0075879CFFB8FF80FF0982F3449CFD4C.taxon	description	Figure 4	en	Maggioni, Tamara, Rimondino, Clara, Taverna, Anabela, Reyna, Paola, Lagger, Cristian, Alurralde, Gastón, Calcagno, Emilia, Tatián, Marcos (2022): Abyssal ascidians (Chordata, Tunicata) from the Weddell Sea, Antarctica, including a new Styela species and stomach content identifications. Zootaxa 5093 (3): 296-314, DOI: https://doi.org/10.11646/zootaxa.5093.3.2
0075879CFFB8FF80FF0982F3449CFD4C.taxon	materials_examined	Material examined: 63 ° 34 ’ S, 50 ° 41 ’ W, station 13, 2610 m, 14 March 2005, one specimen epibiotic of Culeolus suhmi. Holotype: MZUCVI 0195	en	Maggioni, Tamara, Rimondino, Clara, Taverna, Anabela, Reyna, Paola, Lagger, Cristian, Alurralde, Gastón, Calcagno, Emilia, Tatián, Marcos (2022): Abyssal ascidians (Chordata, Tunicata) from the Weddell Sea, Antarctica, including a new Styela species and stomach content identifications. Zootaxa 5093 (3): 296-314, DOI: https://doi.org/10.11646/zootaxa.5093.3.2
0075879CFFB8FF80FF0982F3449CFD4C.taxon	etymology	Etymology: In reference to the oceanographic campaign ANDEEP III in which the specimen was collected.	en	Maggioni, Tamara, Rimondino, Clara, Taverna, Anabela, Reyna, Paola, Lagger, Cristian, Alurralde, Gastón, Calcagno, Emilia, Tatián, Marcos (2022): Abyssal ascidians (Chordata, Tunicata) from the Weddell Sea, Antarctica, including a new Styela species and stomach content identifications. Zootaxa 5093 (3): 296-314, DOI: https://doi.org/10.11646/zootaxa.5093.3.2
0075879CFFB8FF80FF0982F3449CFD4C.taxon	description	Description. The specimen measures 0.37 cm high and 0.4 cm wide, with both apertures pointing towards the oral aperture of its basibiont. These are located at a short distance from each other. The tunic is thick and opaque, with a yellowish-brown tone (Fig. 4 A). There are 22 simple oral tentacles of three different sizes, disposed in a circle on a thickening of the mantle. The pre-pharyngeal band is simple and undulated. It encloses a rounded dorsal tubercle in a small indentation. The dorsal lamina has a smooth border with slight undulations. It is continuous and tall, with its distal border curving on itself. The musculature consists of very thin fibers evenly distributed on the mantle, which is very thick. The branchial sac has thick and compressed longitudinal and transverse vessels. The latter alternate with thinner transverse vessels. The branchial longitudinal vessels are disposed as follows: Left side: DL - 4 (7) 3 (6) 4 (10) 6 (6) 2 - E Right side: DL - 7 (9) 5 (11) 6 (10) 4 (8) 6 - E The gut forms a very closed loop. There is a short esophagus that connects with a cylindrical stomach, which occupies almost ⅓ of the distance between the endostyle and the dorsal lamina. The stomach has 10 internal longitudinal folds. The intestine forms a swelling at its most proximal end. The border of the anus is lobed. There are two gonads on each side of the body. The tubular ovaries are long and thin, of an undulated, almost snaking shape. The most distant part of the posterior ovary on the left side is covered by the intestine. Small masses of testicular follicles surround the distal ends of each ovary, all disposed in close contact, although not attached, to them. In total, there are 13 endocarps on the right side of the body and nine on the left side. On the left side, the antero-dorsal ovary is completely covered by a row of six endocarps attached dorsally, while the postero-ventral ovary has a small row of two endocarps on its ventral side. In addition, there is a big endocarp at a mid-distance between both left gonads. On the right side, the antero-dorsal ovary is partially covered by a row of four endocarps dorsally. There is also one small endocarp on its ventral side, close to the testicular follicles. The postero-ventral ovary has a row of four endocarps on its ventral side. In addition, there are three small endocarps located dorsal, ventral and next to the testicular follicles of this gonad. Finally, there is a big endocarp at a mid-distance between the right gonads (Fig. 4 B). Stomach contents. No items were found in this specimen.	en	Maggioni, Tamara, Rimondino, Clara, Taverna, Anabela, Reyna, Paola, Lagger, Cristian, Alurralde, Gastón, Calcagno, Emilia, Tatián, Marcos (2022): Abyssal ascidians (Chordata, Tunicata) from the Weddell Sea, Antarctica, including a new Styela species and stomach content identifications. Zootaxa 5093 (3): 296-314, DOI: https://doi.org/10.11646/zootaxa.5093.3.2
0075879CFFB8FF80FF0982F3449CFD4C.taxon	discussion	Remarks. Styela andeepensis sp. nov. is very close to Styela glans Herdman, 1881, whose geographic range encompasses the South Western Atlantic and the Southern oceans (including the Weddell Sea) at a bathymetric range from 35 m to 1680 m (Herdman 1881; Monniot C. & Monniot F. 1976; Monniot C. 1978; Monniot C. & Monniot F. 1980; Monniot C. & Monniot F. 1983; Monniot C. & Monniot F. 1994). The main differences between both species include: the structure of the branchial sac, with S. andeepensis sp. nov. having true folds and S. glans having only an accumulation of longitudinal vessels; the size and shape of the ovaries, being shorter and wider in S. glans; the number and disposition of endocarps, being more numerous in S. glans; the presence of parastigmatic vessels in S. glans, being completely absent in S. andeepensis sp. nov.; and the presence of atrial tentacles, being numerous in S. glans but completely absent in S. andeepensis sp. nov. Styela andeepensis sp. nov. is also very close to Styela magalhaensis Michaelsen, 1898, a species cited for the SE Pacific, SW Atlantic and Southern oceans (Michaelsen 1900; Ärnbäck-Christie-Linde 1929; Millar 1960; Millar 1970; Diehl 1977; Monniot C. & Monniot F. 1983; Monniot C. & Andrade 1983) at a maximum depth of 495 m (Diehl, 1977). However, they differ in the following characters: the ovaries have similar lengths, but are wider and have a straight shape in S. magalhaensis (not the characteristic snaking shape found in S. andeepensis sp. nov.); the testicular follicles in S. magalhanesis form compact clusters disposed very close to the lower end of the ovaries, with almost no distance between them, while in S. andeepensis sp. nov. they form smaller clusters disposed close but at some distance from the distal end of the ovaries; atrial tentacles are present in S. magalhaensis, while they are completely absent in S. andeepensis sp. nov.; endocarps are more numerous in S. magalhaensis; the gut-loop is wider and the stomach is longer in S. magalhaensis; and the pre-pharyngeal band makes a pronounced V around the dorsal tubercle in S. magalhaensis. Styela brevigaster Millar (1988) is found in the SE Pacific at bathyal depths (550 – 750 m). Millar (1988) acknowledged its close similarity to S. magalhaensis, from which it was differentiated by the dimension and shape of the stomach. The specimens observed by Millar (more than 100) presented shorter and wider stomachs in comparison to the long and cylindrical stomachs observed by Michaelsen (1900) in S. magalhaensis. Styela andeepensis sp. nov. has a long, cylindrical stomach, more similar to that of S. magalhaensis. Styela atlantica (Van Name, 1912) and Styela sigma Hartmeyer, 1906 are two almost identical species. Both resemble very closely S. andeepensis sp. nov. when morphological characters are compared. However, the number of endocarps are fewer than those reported for S. sigma (approximately 83 on one side; Nishikawa T. 1991, figure 32 A) and S. atlantica (approximately 30 on the right side; Monniot F. 2016, figure 26 A, B). In addition, there are no tentancles near the atrial aperture as observed for S. atlantica (Monniot F. 2016) nor an “ atrial velum welldeveloped, sprinkled with numerous fine atrial tentacles over its inner surface ” as described for S. sigma (Nishikawa T. 1991). The species S. atlantica is found in the northern hemisphere, in Atlantic waters down to 300 m (Monniot F. 2016); S. sigma is found in the northern hemisphere, in Pacific waters down to 800 m (Sanamyan K. 2000). Other Styela species with two gonads on each side of the body, which are also very close to S. andepeensis sp. nov. are Styela canopus (Savigny, 1816) and Styela partita (Stimpson, 1852). However, these species have testis follicles distributed along both sides of the ovaries (not forming apical clusters as in S. andeepensis sp. nov.). Both were collected from shallow waters in the central Atlantic (Van Name 1945; Monniot C. 1983; Rocha et al. 2012).	en	Maggioni, Tamara, Rimondino, Clara, Taverna, Anabela, Reyna, Paola, Lagger, Cristian, Alurralde, Gastón, Calcagno, Emilia, Tatián, Marcos (2022): Abyssal ascidians (Chordata, Tunicata) from the Weddell Sea, Antarctica, including a new Styela species and stomach content identifications. Zootaxa 5093 (3): 296-314, DOI: https://doi.org/10.11646/zootaxa.5093.3.2
0075879CFFB9FF8EFF09879C45AAFEA0.taxon	description	Figure 5	en	Maggioni, Tamara, Rimondino, Clara, Taverna, Anabela, Reyna, Paola, Lagger, Cristian, Alurralde, Gastón, Calcagno, Emilia, Tatián, Marcos (2022): Abyssal ascidians (Chordata, Tunicata) from the Weddell Sea, Antarctica, including a new Styela species and stomach content identifications. Zootaxa 5093 (3): 296-314, DOI: https://doi.org/10.11646/zootaxa.5093.3.2
0075879CFFB9FF8EFF09879C45AAFEA0.taxon	materials_examined	Material examined: 63 ° 34 ’ S, 50 ° 41 ’ W, station 13, 2610 m, 14 March 2005, five specimens.	en	Maggioni, Tamara, Rimondino, Clara, Taverna, Anabela, Reyna, Paola, Lagger, Cristian, Alurralde, Gastón, Calcagno, Emilia, Tatián, Marcos (2022): Abyssal ascidians (Chordata, Tunicata) from the Weddell Sea, Antarctica, including a new Styela species and stomach content identifications. Zootaxa 5093 (3): 296-314, DOI: https://doi.org/10.11646/zootaxa.5093.3.2
0075879CFFB9FF8EFF09879C45AAFEA0.taxon	description	Description. All specimens have the same external appearance and size (Fig. 5 A). On average, they measure 5.5 cm wide and 3.5 cm long. The tunic is dull brown, completely covered by small vesicles. The atrial aperture is completely surrounded by a circular crest of crowded papillae forming a wide band made up of two to three rows. The papillae forming the crest are also covered by vesicles, as the rest of the tunic (Fig. 5 B). Three of the samples have an extension of the crest running along the whole mid-ventral side of the body. The remaining two samples have this extension interrupted a very short distance from the crest. There are approximately 25 wide oral tentacles with ramifications of first and second orders and of two different sizes. These are distributed interspaced in a circle. The oral velum has a smooth border. The pre-pharyngeal band is double and circular, with slight undulations. The dorsal tubercle has a “ C ” shape. The dorsal lamina consists of a series of triangular languets that extends from the base of the dorsal tubercle to almost the entrance of the esophagus. The mantle is thin and delicate, but the musculature is thick. Transversal and longitudinal muscle fibers form a gridded network that covers the totality of the body. The branchial sac has no stigmata. It consists of a mesh of longitudinal and transverse vessels. The branchial formula for the largest specimen is: E - 2 (8) 6 (10) 6 (12) 7 (15) 7 (12) 6 (11) 4 - DL DL - 4 (13) 5 (11) 6 (12) 10 (11) 8 (9) 4 (9) 4 - E The gut forms an open loop. The esophagus is short. The stomach is completely covered by hepatic diverticula. The border of the anus has multiple and small lobes. Except for one damaged specimen, there are two gonads on the left side and two gonads on the right side (Fig. 5 C). The number of gonadal lobes varies between one and eight: the first specimen (3.5 cm long and 5.5 cm wide) has four lobes in the posterior left gonad, eight lobes in the anterior left gonad, three lobes in the posterior right gonad, and six lobes in the anterior right gonad; the second specimen (3.5 cm long and 7 cm wide) has five lobes in the posterior left gonad, seven lobes in the anterior left gonad, three lobes in the posterior right gonad, and seven lobes in the anterior right gonad; the third specimen (2.5 cm long and 5 cm wide) has four lobes in the posterior left gonad, five lobes in the anterior left gonad, three lobes in the posterior right gonad, and five lobes in the anterior right gonad; the fourth specimen (4 cm long and 6 cm wide) has four lobes in the posterior left gonad, five lobes in the anterior left gonad, three lobes in the posterior right gonad, and five lobes in the anterior right gonad; the fifth specimen (damaged; 1.8 cm long and 3 cm wide) has only one gonad on the left side inside the gut loop with six lobes, while both right gonads have one lobe each. The position of the gonads in relation to the gut-loop is constant in all the specimens. On the left side, both gonads have the same length as the descending limb of the gut-loop. On the right side, the gonads run parallel to the endostyle and to each other. The posterior gonad, closer to the endostyle, is shorter than the anterior (Fig. 5 C). Adhered to the peduncle and to the ventral side of the body of two adult specimens, we found two solitary ascidians that could not be identified due to their early stage of development (Fig. 5 A). They measure 1 cm wide by 1 cm long and 2 cm wide by 2 cm long and have an ovoid shape. The tunic that surrounds them is thin and transparent, with thin and numerous projections. Stomach contents. In the stomach of three specimens we found pellet-shaped material (fecal pellets). In addition, in one of these we also found a complete amphipod (undetermined).	en	Maggioni, Tamara, Rimondino, Clara, Taverna, Anabela, Reyna, Paola, Lagger, Cristian, Alurralde, Gastón, Calcagno, Emilia, Tatián, Marcos (2022): Abyssal ascidians (Chordata, Tunicata) from the Weddell Sea, Antarctica, including a new Styela species and stomach content identifications. Zootaxa 5093 (3): 296-314, DOI: https://doi.org/10.11646/zootaxa.5093.3.2
0075879CFFB9FF8EFF09879C45AAFEA0.taxon	discussion	Remarks. This is the first record of Culeolus suhmi in the Southern Ocean. It is also the southern record and the only geographic location that is shared with C. anonymus. The genus Culeolus has a high intra-specific variability of characters frequently used for species identification (Monniot C. & Monniot F. 1976; Kott 2002; Sanamyan K. & Sanamyan N. 2002). These characters are the position and number of the gonads and the structure of the postero-ventral crest (Sanamyan K. & Sanamyan N. 2002). Monniot C. & Monniot F. (1976) used the position of the gonads in relation to each other and to the gut-loop and the border of the anus to establish differences between Culeolus suhmi and C. anonymus, a species cited for the SW Atlantic area. Based on new material and on revisions of previously identified material, Sanamyan K. & Sanamyan N. (2002) doubted the value of these characters for delimitation of the discussed species because they were highly variable. They concluded that the only character stable enough to distinguish between C. anonymus and Culeolus suhmi is the shape of the crest. The number of gonads is variable in some species of the genus Culeolus, like in Culeolus suhmi (Sanamyan K. & Sanamyan N. 2005). After the study of new material the authors concluded that, even though in the majority of specimens the number of gonads on the right side is two, it could also ascend to three. Previously, Sanamyan K. & Sanamyan N. (2002) had suggested that this could be the product of an abnormality. In regard to the ascidian epibionts found, we could only detect a rudimentary endostyle and digestive tract, with no signs of branchial sac, gonads or muscular tissue. Unfortunately, due to the condition of these specimens no more details could be provided. The presence of ascidians in an early state of development attached to the bodies of adult conspecific specimens has been associated with gregarious behaviours in shallow water environments (Manríquez & Castilla 2007; Castilla et al. 2007). In addition, some studies of associations among interspecific ascidians pointed to predation as the selective force maintaining the association (Young 1989; Davis 1996). Ascidian-ascidian associations, however, are not an exclusive attribute of shallow water environments. Although to a lesser extent, deep-sea ascidians have also been observed as basibionts and epibionts of other ascidians, including specimens of the genus Culeolus (Monniot C. & Monniot F. 1982; Sanamyan K. & Sanamyan N. 2002). Notwithstanding, the causes of this phenomenon at deeper depths still remain uncertain (Maggioni et al. in prep.).	en	Maggioni, Tamara, Rimondino, Clara, Taverna, Anabela, Reyna, Paola, Lagger, Cristian, Alurralde, Gastón, Calcagno, Emilia, Tatián, Marcos (2022): Abyssal ascidians (Chordata, Tunicata) from the Weddell Sea, Antarctica, including a new Styela species and stomach content identifications. Zootaxa 5093 (3): 296-314, DOI: https://doi.org/10.11646/zootaxa.5093.3.2
0075879CFFB7FF8CFF0987F8456CFCE0.taxon	description	Figure 6	en	Maggioni, Tamara, Rimondino, Clara, Taverna, Anabela, Reyna, Paola, Lagger, Cristian, Alurralde, Gastón, Calcagno, Emilia, Tatián, Marcos (2022): Abyssal ascidians (Chordata, Tunicata) from the Weddell Sea, Antarctica, including a new Styela species and stomach content identifications. Zootaxa 5093 (3): 296-314, DOI: https://doi.org/10.11646/zootaxa.5093.3.2
0075879CFFB7FF8CFF0987F8456CFCE0.taxon	materials_examined	Material examined: 68 ° 32 ’ S, 20 ° 34 ’ W, station 9, 4930 m, 27 Feb 2005, one specimen.	en	Maggioni, Tamara, Rimondino, Clara, Taverna, Anabela, Reyna, Paola, Lagger, Cristian, Alurralde, Gastón, Calcagno, Emilia, Tatián, Marcos (2022): Abyssal ascidians (Chordata, Tunicata) from the Weddell Sea, Antarctica, including a new Styela species and stomach content identifications. Zootaxa 5093 (3): 296-314, DOI: https://doi.org/10.11646/zootaxa.5093.3.2
0075879CFFB7FF8CFF0987F8456CFCE0.taxon	description	Description. The only specimen collected was found attached to the peduncle of Culeolus suhmi. Its body measures 1.8 cm long and 2.7 cm wide while the length of the peduncle reaches 6.5 cm, the shortest measure reported so far. The tunic is white (Fig. 6 A). It is completely covered by tiny rounded-tipped vesicles, which give the surface of the animal a granulated aspect (Fig. 6 B). The atrial aperture is surrounded by a crest of papillae interrupted dorsally. In the ventral region, the papillae of the crest are thicker and attached by their sides, creating a sort of stout lamella. There are no papillae in the mid-ventral region nor in any other region of the body (Figs. 6 A, B). There are 32 oral tentacles, with ramifications of the one order, disposed in a circle. Bigger tentacles with wide bases are distributed interspaced with smaller and thinner tentacles. Some of the bases of the bigger tentacles are so wide that they extend beyond the line of insertion towards the oral aperture. There is no oral velum. The dorsal tubercle has a “ C ” shape. The pre-pharyngeal band is simple. It makes a pronounced V around the dorsal tubercle. The dorsal lamina is composed of 20 triangular languets. Strong muscle fibers form a gridded network over the mantle. The branchial sac has six folds on each side. The branchial formula for the left side is: DL - 2 (7) 2 (6) 3 (9) 3 (7) 3 (6) 2 (4) 4 - E There is a short esophagus that connects with a small stomach, which is covered by two rows of hepatic diverticula. The intestine is long and thick. The border of the anus has multiple lobes. A short atrial velum was observed. There are two gonads on each side of the body. On the left side, the posterior gonad is located inside the gut-loop, while the anterior gonad is located antero-dorsal to the gut-loop. Both right gonads are located parallel to the endostyle, in one line, one after another. The anterior gonads on both sides of the body have two lobes, while the ventral gonads have only one (Fig. 6 C). Stomach contents. In the stomach of this specimen we found pellet-shaped material (fecal pellets).	en	Maggioni, Tamara, Rimondino, Clara, Taverna, Anabela, Reyna, Paola, Lagger, Cristian, Alurralde, Gastón, Calcagno, Emilia, Tatián, Marcos (2022): Abyssal ascidians (Chordata, Tunicata) from the Weddell Sea, Antarctica, including a new Styela species and stomach content identifications. Zootaxa 5093 (3): 296-314, DOI: https://doi.org/10.11646/zootaxa.5093.3.2
0075879CFFB7FF8CFF0987F8456CFCE0.taxon	discussion	Remarks. Millar (1959) was the first who recognized two different species based on the morphologies of the postero-ventral crests of several specimens of Culeolus, which he temporarily identified as Culeolus suhmi. After the study of new material, Monniot C. & Monniot F. (1976) identified all specimens with postero-ventral crests interrupted dorsally as Culeolus anonymus. The authors originally described two populations based on the shape of the crest: one group with a continuous crest and the other with a crest composed of separate papillae. However, subsequent samples showed the existence of intermediate forms (Monniot C. & Monniot F. 1982). The number of branchial folds may also vary in C. anonymus. Although the most frequent is six folds per side, Sanamyan K. & Sanamyan N. (1999) observed five folds in specimens collected in the Indo-Pacific. Other species of Culeolus recorded in the Southern Ocean are: Culeolus antarcticus Vinogradova, 1962; Culeolus likae Sanamyan K. & Sanamyan N., 2002; Culeolus pinguis Monniot C. & Monniot F., 1982; and Culeolus recumbens Herdman, 1881. Culeolus anonymus is clearly distinguished from C. antarcticus and C. likae by the shape of the postero-ventral crest and by the number of gonads. The crest of both, C. antarcticus and C. likae, consists of a lamella that completely surrounds the atrial aperture and is interrupted dorsally, and extends along the mid-ventral side of the body. Moreover, C. antarcticus has one gonad consisting of one lobe on each side of the body, while C. likae presents three gonads per side. Culeolus pinguis presents a postero-ventral crest that surrounds the atrial aperture and two gonads with two lobes on each side. Finally, C. recumbens does not present gonads outside the gut-loop, and the postero-ventral crest completely surrounds the atrial aperture. In a revision of the genus, Kott (2002) proposed the synonymy between C. anonymus and Culeolus suhmi. This statement, although possible, is difficult to maintain based on the present available data. As such, the position and morphology of the gonads of the present specimen of C. anonymus is almost identical to the figure presented by Monniot C. & Monniot F. (1973) for specimens of Culeolus suhmi from the North Atlantic. However, the gonads of C. anonymus and Culeolus suhmi are extremely variable and, in some cases, almost identical. Although the only robust feature to differentiate between Culeolus suhmi and C. anonymus is the configuration of the postero-ventral crest (Sanamyan K. & Sanamyan N. 2002), the finding of two species in the Weddell Sea, one with internal characters more frequently found in the other, could be indicating that these species are, in fact, conspecific. However, until more material is available and completed with molecular studies, we propose to maintain C. anonymus and C. suhmi as separate species. In the most recent revision of the genus, Sanamyan et al. (2018) suggested that C. wivylle-thomsoni and C. anonymus could be conspecific based on a commentary by Monniot C. & Monniot F. (1982). According to the latter authors, the type specimen of C. wivylle-thomsoni could be an abnormal specimen of C. anonymus. Culeolus wivylle-thomsoni has not been collected since its original finding (see Herdman, 1881).	en	Maggioni, Tamara, Rimondino, Clara, Taverna, Anabela, Reyna, Paola, Lagger, Cristian, Alurralde, Gastón, Calcagno, Emilia, Tatián, Marcos (2022): Abyssal ascidians (Chordata, Tunicata) from the Weddell Sea, Antarctica, including a new Styela species and stomach content identifications. Zootaxa 5093 (3): 296-314, DOI: https://doi.org/10.11646/zootaxa.5093.3.2
0075879CFFB5FF8AFF0981CA4302FF44.taxon	description	Figure 7	en	Maggioni, Tamara, Rimondino, Clara, Taverna, Anabela, Reyna, Paola, Lagger, Cristian, Alurralde, Gastón, Calcagno, Emilia, Tatián, Marcos (2022): Abyssal ascidians (Chordata, Tunicata) from the Weddell Sea, Antarctica, including a new Styela species and stomach content identifications. Zootaxa 5093 (3): 296-314, DOI: https://doi.org/10.11646/zootaxa.5093.3.2
0075879CFFB5FF8AFF0981CA4302FF44.taxon	materials_examined	Material examined: 70 ° 40 ’ S, 14 ° 43 ’ W, station 7, 3000 m, 22 Feb 2005, one specimen; 68 ° 32 ’ S, 20 ° 24 ’ W, station 9, 4930 m, 27 Feb 2005, one specimen.	en	Maggioni, Tamara, Rimondino, Clara, Taverna, Anabela, Reyna, Paola, Lagger, Cristian, Alurralde, Gastón, Calcagno, Emilia, Tatián, Marcos (2022): Abyssal ascidians (Chordata, Tunicata) from the Weddell Sea, Antarctica, including a new Styela species and stomach content identifications. Zootaxa 5093 (3): 296-314, DOI: https://doi.org/10.11646/zootaxa.5093.3.2
0075879CFFB5FF8AFF0981CA4302FF44.taxon	description	Description. Both specimens have a similar external aspect (Fig. 7 A). The smaller specimen is 4 cm long and 1.7 cm wide, while its peduncle reaches 15 cm in length. The larger specimen is 10.9 cm long and 5.2 cm wide, while its peduncle reaches 187 cm in length. The tunic is white, almost transparent, through which body muscles can be seen. After formalin preservation it turns yellowish. It has a smooth appearance, although it is completely covered by tiny vesicles with pointy tips arranged somewhat away from each other (Fig. 7 B). The postero-ventral crest is T-shaped: it consists of 3 continuous lamellae that end halfway along the body. The two lamellae that encircle the atrial aperture are interrupted at the dorsal region, failing to form a complete circle. The remaining third lamella runs through the mid-ventral line of the body. The oral siphon is situated at a short distance from the peduncle. The atrial siphon, situated posteriorly, is large. In the bigger specimen it measures 2 cm in diameter. A total of 34 oral tentacles of three different sizes are disposed in a circle. They have ramifications of three orders. The oral tentacle located over the dorsal region is the biggest. The pre-pharyngeal band is at a short distance from the oral aperture. It is composed of two smooth lamellae and makes a marked V around a prominent “ C ” - shaped dorsal tubercle. The dorsal lamina, composed of separate triangular languets, extends from the border of the dorsal tubercle until the entrance of the esophagus. In the biggest specimen, we counted 55 languets. Strong longitudinal muscle fibers intercalate with strong transverse muscle fibers, forming a mesh. Thinner circular fibers are disposed around both siphons. There are six folds on each side of the branchial sac. The branchial formula for the left side of the biggest specimen is: DL - 7 (10) 6 (10) 8 (6) 10 (7) 7 (5) 5 (5) 8 - E The gut makes an open loop. The stomach is covered by two rows of hepatic diverticula. There is a wide atrial velum, with curved borders. The anal boder is smooth. Each gonad consists of a compact globular mass composed of numerous testicular follicles distributed over a short ovary. Both structures are embedded in a big endocarp. The gonads do not present lobes. There are three gonads on each side of the body. On the left side, the most ventral gonad is small and located in the gut-loop. The remaining two are located almost parallel to the intestine. On the right side, two gonads run almost parallel to the endostyle, one under the other. The remaining gonad, bigger in size, is located dorsally (Fig. 7 C). Stomach contents. No remains of prey items were found.	en	Maggioni, Tamara, Rimondino, Clara, Taverna, Anabela, Reyna, Paola, Lagger, Cristian, Alurralde, Gastón, Calcagno, Emilia, Tatián, Marcos (2022): Abyssal ascidians (Chordata, Tunicata) from the Weddell Sea, Antarctica, including a new Styela species and stomach content identifications. Zootaxa 5093 (3): 296-314, DOI: https://doi.org/10.11646/zootaxa.5093.3.2
0075879CFFB5FF8AFF0981CA4302FF44.taxon	discussion	Remarks. This is the third record of Culeolus likae, increasing to seven the total number of specimens recorded. The geographic and bathymetric ranges of the species are extended, being the present the southern and shallowest register. The smaller specimen studied lacks part of the branchial sac, digestive system and gonads. Only the musculature, neural system, oral tentacles and dorsal lamina are intact. Notwithstanding, the external aspect is identical to the description for the species provided by Sanamyan K. & Sanamyan N. (2002). The larger specimen presents a peduncle which is 1 m longer than the longitude reported by the latter authors for the biggest specimen they collected (the holotype). Even though the position and the structure of the gonads may vary in some species of Culeolus, our intact specimen has the same position and shape of the one provided by Sanamyan K. & Samanyan N. (2002) for the holotype of C. likae. The differences found are: a higher number of oral tentacles (34 in our specimen; 20 in the holotype), the shape of the dorsal tubercle (“ S ” - shaped instead of “ C ” - shaped) and the border of the anus (with two lobes instead of smooth). The difference in the number of oral tentacles could be due to the difference in size of the individuals compared. The shape of the dorsal tubercle is variable in numerous ascidian species; thus, we do not consider it a reliable character in the case of species diagnosis. The difference in the border of the anus might be attributed to incomplete fixation.	en	Maggioni, Tamara, Rimondino, Clara, Taverna, Anabela, Reyna, Paola, Lagger, Cristian, Alurralde, Gastón, Calcagno, Emilia, Tatián, Marcos (2022): Abyssal ascidians (Chordata, Tunicata) from the Weddell Sea, Antarctica, including a new Styela species and stomach content identifications. Zootaxa 5093 (3): 296-314, DOI: https://doi.org/10.11646/zootaxa.5093.3.2
0075879CFFB3FF89FF0983BE4256FE6C.taxon	description	Figure 8 Gasterascidia lyra Monniot C. & Monniot F. 1973: 457, figs. 31 E – F, 32, 33 A; Monniot C. & Monniot F. 1974: 777; Monniot C. & Monniot F. 1977: 697; Monniot C. & Monniot F. 1984 a: 209; Monniot C. & Monniot F. 1984 b: 131; Monniot C. & Monniot F. 1985: 35; Monniot C. & Monniot F. 1990: 251, figs. 1 B, 5 A – C.	en	Maggioni, Tamara, Rimondino, Clara, Taverna, Anabela, Reyna, Paola, Lagger, Cristian, Alurralde, Gastón, Calcagno, Emilia, Tatián, Marcos (2022): Abyssal ascidians (Chordata, Tunicata) from the Weddell Sea, Antarctica, including a new Styela species and stomach content identifications. Zootaxa 5093 (3): 296-314, DOI: https://doi.org/10.11646/zootaxa.5093.3.2
0075879CFFB3FF89FF0983BE4256FE6C.taxon	materials_examined	Material examined: 62 ° 9 ’ S, 49 ° 3 ’ W, station 14, 3400 m, 18 March 2005, four specimens.	en	Maggioni, Tamara, Rimondino, Clara, Taverna, Anabela, Reyna, Paola, Lagger, Cristian, Alurralde, Gastón, Calcagno, Emilia, Tatián, Marcos (2022): Abyssal ascidians (Chordata, Tunicata) from the Weddell Sea, Antarctica, including a new Styela species and stomach content identifications. Zootaxa 5093 (3): 296-314, DOI: https://doi.org/10.11646/zootaxa.5093.3.2
0075879CFFB3FF89FF0983BE4256FE6C.taxon	description	Description. The four specimens measure from 2.2 to 3.6 cm long (distances between the oral and atrial apertures). The tunic is transparent. It is completely covered by thin projections and detritus. Some individuals also had rests of sponges and polichaete tubes. The oral siphon, made up of six prominent oral lobes, occupies one third of the total length of the body (Fig. 8 A). Its internal wall has seven longitudinal rows of approximately 16 papillae. The atrial siphon is located posteriorly and consists in a projection of variable size (although always smaller than the oral siphon). At the base of the oral siphon there are 14 small oral tentacles distributed in a circle (Fig. 8 B). Below this row of tentacles, the reduced branchial sac has numerous circular perforations that connect with the atrial cavity. The mantle is thin and transparent. The musculature is strong: densely distributed thick muscle fibers cover most of the body. The oral siphon is completely innervated by longitudinal fibers. The oral lobes and the base of the oral siphon are covered by a series of circular fibers. On each side of the oral siphon, from its base until the middle of the body, a group of longitudinal fibers extend and cover both right and left gonads. In between both siphons, over the dorsal region, there is another group of transversal muscle fibers. The ventral region does not have any musculature. The esophagus is short and wide. It connects with a large and rounded stomach, which occupies more than half of the body. The stomach walls are thin, smooth and delicate. On top of the stomach, at the level of the esophagus, there is an oval vesicle with a concretion in its interior. The rectum is short and ends near the atrial siphon. There is one gonad on each side of the body. The tubular ovaries have a characteristic “ S ” shape and are full of ovocytes. On the distal ends of both ovaries there are two clumps of testicular follicles. The oviduct is short and wide and ends in the atrial cavity. Stomach contents. We found zooplanktonic prey items in only one specimen: one amphipod (undet.); a fragment of an isopod; and fragments of what could belong to Isopoda or Tanaidacea crustaceans. The remaining specimens had: an empty stomach, a stone, and detritus.	en	Maggioni, Tamara, Rimondino, Clara, Taverna, Anabela, Reyna, Paola, Lagger, Cristian, Alurralde, Gastón, Calcagno, Emilia, Tatián, Marcos (2022): Abyssal ascidians (Chordata, Tunicata) from the Weddell Sea, Antarctica, including a new Styela species and stomach content identifications. Zootaxa 5093 (3): 296-314, DOI: https://doi.org/10.11646/zootaxa.5093.3.2
0075879CFFB3FF89FF0983BE4256FE6C.taxon	discussion	Remarks. Although the species is cosmopolitan, its records are more frequent in the northern hemisphere. This is the second register of O. lyra in the Weddell Sea. On the revision of the family Hexacrobylidae, Kott (1989) established that the species assigned to S orbera Monniot C. & Monniot F. 1974 and to Gasterascidia Monniot C. & Monniot F. 1968 presented all characters assigned to Oligotrema, and that the differences did not justify the maintenance of both genera. To this author, Sorbera and Gasterascidia are junior synonyms of Oligotrema.	en	Maggioni, Tamara, Rimondino, Clara, Taverna, Anabela, Reyna, Paola, Lagger, Cristian, Alurralde, Gastón, Calcagno, Emilia, Tatián, Marcos (2022): Abyssal ascidians (Chordata, Tunicata) from the Weddell Sea, Antarctica, including a new Styela species and stomach content identifications. Zootaxa 5093 (3): 296-314, DOI: https://doi.org/10.11646/zootaxa.5093.3.2
0075879CFFB0FF88FF09800F4386FCE0.taxon	description	Figure 9	en	Maggioni, Tamara, Rimondino, Clara, Taverna, Anabela, Reyna, Paola, Lagger, Cristian, Alurralde, Gastón, Calcagno, Emilia, Tatián, Marcos (2022): Abyssal ascidians (Chordata, Tunicata) from the Weddell Sea, Antarctica, including a new Styela species and stomach content identifications. Zootaxa 5093 (3): 296-314, DOI: https://doi.org/10.11646/zootaxa.5093.3.2
0075879CFFB0FF88FF09800F4386FCE0.taxon	materials_examined	Material examined: 70 ° 40 ’ S, 14 ° 43 ’ W, station 7, 3000 m, 22 Feb 2005, one specimen.	en	Maggioni, Tamara, Rimondino, Clara, Taverna, Anabela, Reyna, Paola, Lagger, Cristian, Alurralde, Gastón, Calcagno, Emilia, Tatián, Marcos (2022): Abyssal ascidians (Chordata, Tunicata) from the Weddell Sea, Antarctica, including a new Styela species and stomach content identifications. Zootaxa 5093 (3): 296-314, DOI: https://doi.org/10.11646/zootaxa.5093.3.2
0075879CFFB0FF88FF09800F4386FCE0.taxon	description	Description. The only specimen collected measures 3.1 cm long and 2.3 cm wide. With the exception of the oral lobes, the rest of the tunic is completely covered by detritus and sand. The ventral side has short and thin projections. The tunic is transparent, thin and flexible except for the region that surrounds the oral siphon, where it becomes thicker. Surrounding the oral aperture there are six prominent oral lobes with pinnate borders, two of which are bigger than the remaining four. The atrial siphon, situated at approximately one fifth of the distance from the oral siphon, consists of a tiny, almost unnoticeable, hole. The oral siphon is innervated by a series of longitudinal and circular very well developed muscle fibers. The elongated atrial siphon is also innervated by a series of thinner longitudinal and circular muscle fibers. There are no oral tentacles. Instead, there is a thick muscle cap arranged transversely across the first section of the oral siphon, except for a small dorsal orifice that connects directly with a prominent esophagus. The neural ganglion has two pairs of anterior nerves and one thick posterior nerve that divides into two thinner ones. There are two longitudinal bands of ventral muscles that extend on each side of the mid ventral line of the body and join at the posterior end, and a series of thinner concentric circular fibers on each side of the mid-dorsal region of the body. The rest of the mantle is transparent and thin. The pharynx is short and has two circular perforations that connect with lateral pharyngeal chambers which, in turn, open to the atrial cavity. The stomach occupies the totality of the ventral region. It is connected with a big and plicated hepatic pouch situated over it through a short duct. The gut-loop is closed. The border of the anus has two lobes. The ovoid renal sac is situated ventrally, between the oral siphon and the gut. There is one gonad on each side of the body. The ovaries, tubular and slightly curved, are full of yellowish ovocytes. The gonoducts are short and open near the anus. The testicular follicles are composed of numerous whitish lobes at the distal ends of the ovaries. The sperm ducts are also short and open directly into the atrial cavity. Stomach contents. In the stomach of this specimen we found: one fragment of a copepod (undet.); a head fragment of another copepod (undet.); and a Brachyura zoea larva.	en	Maggioni, Tamara, Rimondino, Clara, Taverna, Anabela, Reyna, Paola, Lagger, Cristian, Alurralde, Gastón, Calcagno, Emilia, Tatián, Marcos (2022): Abyssal ascidians (Chordata, Tunicata) from the Weddell Sea, Antarctica, including a new Styela species and stomach content identifications. Zootaxa 5093 (3): 296-314, DOI: https://doi.org/10.11646/zootaxa.5093.3.2
0075879CFFB0FF88FF09800F4386FCE0.taxon	discussion	Remarks. This is the first register of the species in the Weddell Sea. Asajirus indicus has one of the largest known geographic ranges within Ascidiacea.	en	Maggioni, Tamara, Rimondino, Clara, Taverna, Anabela, Reyna, Paola, Lagger, Cristian, Alurralde, Gastón, Calcagno, Emilia, Tatián, Marcos (2022): Abyssal ascidians (Chordata, Tunicata) from the Weddell Sea, Antarctica, including a new Styela species and stomach content identifications. Zootaxa 5093 (3): 296-314, DOI: https://doi.org/10.11646/zootaxa.5093.3.2
