taxonID	type	description	language	source
6050E6031550FF96FF2E83CFF41FFE7C.taxon	diagnosis	Diagnosis (after Glasby & Salazar-Vallejo 2021). Pilargids with body depressed, integument papillose to verrucose, present on both segmental and nonsegmental regions. Antennae, 0 – 3. Palps unfused, biarticulated; palpostyle minute. Paired ventrolateral palpal papillae present. Pharynx distally with terminal papillae (or absent); proximally smooth or, rarely, with denticles. Two pairs of tentacular cirri. Dorsal and ventral cirri digitate to lobate. Notochaetae are hooks, present from chaetigers 3 to 13 and continuing throughout body. Neurochaetae smooth, or spinulose capillaries, often with bidentate tips. Free living in sediments from intertidal to deep sea, or commensal with other invertebrates.	en	Plathong, Jintana, Dean, Harlan K., Plathong, Sakanan (2021): Four new species of Pilargidae (Annelida: Pilarginae) from the Gulf of Thailand. Zootaxa 5071 (4): 537-562, DOI: https://doi.org/10.11646/zootaxa.5071.4.4
6050E6031556FF91FF2E83CFF1F8FD90.taxon	description	Figs 2 – 4	en	Plathong, Jintana, Dean, Harlan K., Plathong, Sakanan (2021): Four new species of Pilargidae (Annelida: Pilarginae) from the Gulf of Thailand. Zootaxa 5071 (4): 537-562, DOI: https://doi.org/10.11646/zootaxa.5071.4.4
6050E6031556FF91FF2E83CFF1F8FD90.taxon	materials_examined	Material examined. Twenty one specimens, collected from the Songkhla Sea, Gulf of Thailand, Western Pacific. Coll. MEM (Marine Ecosearch Management Co., Ltd.), mud mixed with sand and shells. Holotype: PSUZC-POL- 0187 (1 spec.), S 02 (7 ° 31 ’ 44 ” N, 100 ° 28 ’ 15 ” E), 15 Mar 2016, 10.0 m. Paratypes: PSUZC-POL- 0188 (1 spec.), S 07 (7 ° 44 ’ 01 ” N, 100 ° 43 ’ 02 ” E), 11 Oct 2012, 26.5 m; PSUZC-POL- 0189 (1 spec. on SEM stub), S 06 (7 ° 20 ’ 10 ” N, 100 ° 36 ’ 59 ” E), 20 Feb 2013, 15.5 m; PSUZC-POL- 0190 (1 spec.), S 09 - 17 (7 ° 31 ’ 55 ” N, 100 ° 43 ’ 06 ” E), 16 Mar 2013, 24.0 m; PSUZC-POL- 0191 (1 spec.), S 21 (7 ° 33 ’ 17 ” N, 100 ° 46 ’ 43 ” E), 3 Jun 2013, 24.0 m; PSUZC- POL- 0192 (1 spec.), S 24 (7 ° 39 ’ 22 ” N, 100 ° 49 ’ 01 ” E), 30 Oct 2014, 27.0 m; PSUZC-POL- 0193 (1 spec.), S 01 (7 ° 46 ’ 29 ” N, 100 ° 24 ’ 42 ” E), 20 May 2015, 9.5 m; PSUZC-POL- 0194 (1 spec.), S 19 (7 ° 21 ’ 01 ” N, 7 ° 21 ’ 01 ” E), 17 Jul 2015, 14.0 m; PSUZC-POL- 0195 (3 specs., 1 spec. on SEM stub), S 08 (7 ° 29 ’ 10 ” N, 100 ° 47 ’ 06 ” E), 16 Mar 2016, 25.0 m; PSUZC-POL- 0196 (1 spec. on SEM stub), S 09 - 3 (7 ° 32 ’ 1 ” N, 100 ° 42 ’ 41 ” E), 16 Aug 2018, 24.0 m; PSUZC-POL- 0197 (1 spec.), S 08 (7 ° 29 ’ 10 ” N, 100 ° 47 ’ 06 ” E), 5 May 2016, 25.0 m; PSUZC-POL- 0198 (1 spec.), S 03 (7 ° 21 ’ 02 ” N, 100 ° 31 ’ 45 ” E), 18 Oct 2016, 9.0 m; PSUZC-POL- 0199 (3 specs., 1 spec. on SEM stub), S 14 (7 ° 26 ’ 14 ” N, 100 ° 36 ’ 13 ” E), 18 Aug 2018, 15.5 m. Additional Material. 2 specs., S 07 (7 ° 44 ’ 01 ” N, 100 ° 43 ’ 02 ” E), 18 May 2016, 26.5 m; 2 specs., S 09 - 10 (7 ° 31 ’ 56 ” N, 100 ° 42 ’ 47 ” E), 17 Mar 2013, 24.3 m. Type locality. Songkhla Sea, Gulf of Thailand (Fig. 1 A).	en	Plathong, Jintana, Dean, Harlan K., Plathong, Sakanan (2021): Four new species of Pilargidae (Annelida: Pilarginae) from the Gulf of Thailand. Zootaxa 5071 (4): 537-562, DOI: https://doi.org/10.11646/zootaxa.5071.4.4
6050E6031556FF91FF2E83CFF1F8FD90.taxon	diagnosis	Diagnosis. Ancistrosyllis lacking eyespots; median and lateral antennae present; tentacular cirri elongate. Dorsal cirri from chaetiger 1; ventral cirri from chaetiger 3. Notopodial hooks from chaetiger 3; neurochaetae with 2 – 3 short limbate chaetae per bundle, each with curved pointed tips and non-limbate capillary chaetae.	en	Plathong, Jintana, Dean, Harlan K., Plathong, Sakanan (2021): Four new species of Pilargidae (Annelida: Pilarginae) from the Gulf of Thailand. Zootaxa 5071 (4): 537-562, DOI: https://doi.org/10.11646/zootaxa.5071.4.4
6050E6031556FF91FF2E83CFF1F8FD90.taxon	description	Description. Holotype complete, 14.2 mm long and 0.45 mm wide for 66 chaetigers. Body whitish, transparent with eggs within body cavity. Paratypes incomplete, depressed, tapered anteriorly, 1.1 – 6.7 mm long, 0.26 – 0.50 mm wide with 9 – 34 chaetigers. Prostomium bilobed, short, broad, papillose, wider than long (163 µm length and 355 µm wide); lateral antennae shorter than palps (Figs 2 A, B, D, 3 A). Posterior prostomial margin with minute papilla like median antenna (23 µm length and 26 µm wide) (Figs 2 B – D, 4 A). Eyespots absent, palps with small ventrolateral palpal papillae (Figs 2 A, D, 3 A). Proboscis retracted in holotype, visible in SEM specimen. Peristomium short; tentacular cirri two pairs, elongate, papillose, subequal, dorsal tentacular cirri slightly longer than ventrals (Figs 2 A – B, D, 4 A). Parapodia sub-biramous with reduced notopodial lobe; neuropodia truncate, straight. Dorsal cirri from first chaetiger, long, slender, papillose, longer than tentacular cirri; first dorsal cirri 3.8 times length of that of chaetiger 2; dorsal cirri increase in length from chaetiger 3 to about chaetiger 10 then decrease in length to posterior region. Ventral cirri from chaetiger 3, shorter than dorsal cirri. Notopodia each with single aciculum; large, strongly curved notopodial hooks (Figs 2 D, 3 A – C, 4 B) from chaetiger 3 (Figs 2 A, 2 D, 4 B) with 1 – 2 hooks per parapodium to the end of body. Neurochaetal bundles with 2 – 3 short limbate chaetae with curved pointed tips (unidentate) and up to six long, narrow, finely non-limbate capillary chaetae (Figs 3 A, B, D – F, 4). Pygidium with two short, digitate, papillose anal cirri.	en	Plathong, Jintana, Dean, Harlan K., Plathong, Sakanan (2021): Four new species of Pilargidae (Annelida: Pilarginae) from the Gulf of Thailand. Zootaxa 5071 (4): 537-562, DOI: https://doi.org/10.11646/zootaxa.5071.4.4
6050E6031556FF91FF2E83CFF1F8FD90.taxon	etymology	Etymology. The new species name is in honor of Miss Kornkanok Charoenmas of the Marine Ecosearch Management Company who has worked on the data base and distribution maps of the benthos in Thailand for more than 10 years. Habitat. Found in 9 – 27 m depth, in mud mixed with sand and shells.	en	Plathong, Jintana, Dean, Harlan K., Plathong, Sakanan (2021): Four new species of Pilargidae (Annelida: Pilarginae) from the Gulf of Thailand. Zootaxa 5071 (4): 537-562, DOI: https://doi.org/10.11646/zootaxa.5071.4.4
6050E6031556FF91FF2E83CFF1F8FD90.taxon	distribution	Distribution. Songkhla Sea, Gulf of Thailand, Western Pacific.	en	Plathong, Jintana, Dean, Harlan K., Plathong, Sakanan (2021): Four new species of Pilargidae (Annelida: Pilarginae) from the Gulf of Thailand. Zootaxa 5071 (4): 537-562, DOI: https://doi.org/10.11646/zootaxa.5071.4.4
6050E6031556FF91FF2E83CFF1F8FD90.taxon	discussion	Remarks. Ancistrosyllis kornkanokae sp. nov. belongs to the second group of species in the genus Ancistrosyllis characterized by the presence of both a median antenna and two lateral antennae and the absence of eyespots (Table 1). Further, A. kornkanokae sp. nov. also has elongate, digitate, papillose tentacular cirri which differentiates this species from the other species in this group. Dorsal cirri are from chaetiger 1, longer than those present along subsequent chaetigers. Ventral cirri short, conical, papillose from chaetiger 3. It resembles A. fioronii Fiege & Böggemann, 1999 from North Sea, Atlantic Ocean; A. hartmanae Pettibone, 1966 from Chesapeake Bay, USA; and A. nakkaritae sp. nov. in group two by having a median antenna, two lateral antennae, and first notopodial hooks begin at chaetiger 3. However, A. kornkanokae sp. nov. differs from A. fioronii and A. nakkaritae sp. nov. because they all have the first ventral cirri from different chaetigers. The first ventral cirri are present at chaetiger 3 in A. kornkanokae but in A. fioronii and A. nakkaritae sp. nov., first ventral cirri start from chaetiger 2 and chaetiger 1, respectively. Moreover, tentacular cirri in A. kornkanokae are longer than A. fioronii (in A. fioronii has short tentacular). A. kornkanokae sp. nov. also differs from A. fioronii by have two types of neurochaetae as short limbate chaeta and long non - limbate chaeta with unidentate tips. Whereas A. fioronii has only one type of non - limbate capillary neurochaeta with bidentate tip (Fiege & Böggemann 1999). Ancistrosyllis kornkanokae sp. nov. differs from A. nakkaritae sp. nov. in that all neurochaetae are unidentate but in A. nakkaritae sp. nov., all neurochaetae have bifid tips. Ancistrosyllis kornkanokae sp. nov. mostly resembles A. hartmanae Pettibone, 1966 in having the first dorsal and ventral cirri occurring on similar chaetigers (chaetiger 1 and chaetiger 3, respectively) and first hooks occur from chaetiger 3 (Pettibone 1966). However, in A. hartmanae eyespots are present and the tentacular cirri are short, while in A. kornkanokae sp. nov. eyespots are absent and the tentacular cirri are longer (Table 1).	en	Plathong, Jintana, Dean, Harlan K., Plathong, Sakanan (2021): Four new species of Pilargidae (Annelida: Pilarginae) from the Gulf of Thailand. Zootaxa 5071 (4): 537-562, DOI: https://doi.org/10.11646/zootaxa.5071.4.4
6050E603155AFF9AFF2E83CFF657FEEC.taxon	description	Figs 5 – 8	en	Plathong, Jintana, Dean, Harlan K., Plathong, Sakanan (2021): Four new species of Pilargidae (Annelida: Pilarginae) from the Gulf of Thailand. Zootaxa 5071 (4): 537-562, DOI: https://doi.org/10.11646/zootaxa.5071.4.4
6050E603155AFF9AFF2E83CFF657FEEC.taxon	materials_examined	Material examined. Five specimens, collected from the Songkhla Sea, Gulf of Thailand, Western Pacific. Coll. MEM (Marine Ecosearch Management Co., Ltd.), mud mixed with sand and shells. Holotype: PSUZC-POL- 0310 (1 spec.), S 06 (7 ° 20 ’ 9 ” N, 100 ° 36 ’ 58 ” E), 15 Mar 2016, 15.5 m. Paratypes: PSUZC-POL- 0311 (1 spec., on SEM stub), S 06 (7 ° 20 ’ 10 ” N, 100 ° 36 ’ 59 ” E), 12 Feb 2015, 15.5 m; PSUZC-POL- 0312 (1 spec.), S 17 (7 ° 36 ’ 16 ” N, 100 ° 34 ’ 48 ” E), 7 Oct 2013, 18.0 m; PSUZC-POL- 0313 (1 spec.), S 02 (7 ° 31 ’ 44 ” N, 100 ° 28 ’ 15 ” E), 15 Mar 2016, 10.0 m; PSUZC-POL- 0314 (1 spec.), S 09 - 3 (7 ° 32 ’ 1 ” N, 100 ° 42 ’ 41 ” E), 16 Aug 2018, 24.0 m. Type locality. Songkhla Sea, Gulf of Thailand (Fig. 1 B).	en	Plathong, Jintana, Dean, Harlan K., Plathong, Sakanan (2021): Four new species of Pilargidae (Annelida: Pilarginae) from the Gulf of Thailand. Zootaxa 5071 (4): 537-562, DOI: https://doi.org/10.11646/zootaxa.5071.4.4
6050E603155AFF9AFF2E83CFF657FEEC.taxon	diagnosis	Diagnosis. Ancistrosyllis nakkaritae sp. nov. is characterized by the absence of eyespots; the presence of a minute, conspicuous median antenna; elongate lateral antennae and tentacular cirri; and the first dorsal and ventral cirri start from chaetiger one. Dorsal and ventral tentacular cirri papillate, as long as lateral antennae, longer than first dorsal cirri. Notopodial hooks from chaetiger 3.	en	Plathong, Jintana, Dean, Harlan K., Plathong, Sakanan (2021): Four new species of Pilargidae (Annelida: Pilarginae) from the Gulf of Thailand. Zootaxa 5071 (4): 537-562, DOI: https://doi.org/10.11646/zootaxa.5071.4.4
6050E603155AFF9AFF2E83CFF657FEEC.taxon	description	Description. Holotype incomplete, 8.7 mm long, 0.6 mm wide with 44 segments. Paratypes incomplete with 2.9 – 6.7 mm long, 0.3 – 0.7 mm wide and 21 – 40 segments. Body whitish, dorsal numerous of long papillae on the dorsal and ventral body throughout. Prostomium broad, papillose, with two elongate papillose digitiform lateral antennae (162 and 130 µm long), longer than the palps (Figs 5 A – B, 6 A – D, 8 A). Median antenna very small, conspicuous present on the posterior of prostomium (Figs 5 B, 6 B, D, 8 A). Eyespots absent, palps with small, digitate ventrolateral palpal papillae (Figs 5 A – B, 6 C – D, 8 A). Proboscis retracted in holotype and paratypes. Peristomium short with two pairs of elongate, digitate, papillose tentacular cirri (up to 203 µm in complete dorsal tentacular cirri) inserted laterally, shorter than palps and longer than first dorsal cirri; dorsal tentacular cirri longer than ventral tentacular cirri and slightly longer than lateral antennae (Figs 5 A – B, 6 A – D, 8 A). Parapodia sub-biramous, with reduced notopodial lobe; neuropodia truncate and straight. Dorsal cirri long, conical, papillose with numerous large, elongate papillae; present from first chaetiger. First dorsal cirri long, about twice length of dorsal cirri at chaetiger 2. Subsequent several dorsal cirri shorter than those of chaetiger 1 but at chaetiger 3 dorsal cirri gradually increase in length until those of midbody being of greater length than those of chaetiger 1. Ventral cirri present from first chaetiger, shorter than dorsal cirri, longer than neuropodial lobes (Figs 5 A, C, 6 A – D, 7 A – C, 8 A, B). Notopodia each with single aciculum, chaetae absent. Large notopodial hooks present from chaetiger 3; strongly curved with one hook per parapodium (Figs 5 A, 6 A, D, 7 B, 8 A). Neurochaetal bundles with 2 – 4 short limbate chaetae with bifid tips and 5 – 8 long, narrow, finely toothed non-limbate chaetae with bifid tips (Figs 7 A – D, 8 B – C). Pygidium unknown. Reproduction. Holotype with eggs (collected in Mar 2016), (Fig. 7 D).	en	Plathong, Jintana, Dean, Harlan K., Plathong, Sakanan (2021): Four new species of Pilargidae (Annelida: Pilarginae) from the Gulf of Thailand. Zootaxa 5071 (4): 537-562, DOI: https://doi.org/10.11646/zootaxa.5071.4.4
6050E603155AFF9AFF2E83CFF657FEEC.taxon	etymology	Etymology. The new species is named in honor of Miss Nuenghathai Nakkarit, the marine biologist at MEM who has worked with us from the beginning of the Songkhla Sea project. Habitat. Found at 10 – 24 m depth, mud mixed with sand and shells.	en	Plathong, Jintana, Dean, Harlan K., Plathong, Sakanan (2021): Four new species of Pilargidae (Annelida: Pilarginae) from the Gulf of Thailand. Zootaxa 5071 (4): 537-562, DOI: https://doi.org/10.11646/zootaxa.5071.4.4
6050E603155AFF9AFF2E83CFF657FEEC.taxon	distribution	Distribution. Songkhla Sea, Gulf of Thailand, Western Pacific (Fig. 1 B).	en	Plathong, Jintana, Dean, Harlan K., Plathong, Sakanan (2021): Four new species of Pilargidae (Annelida: Pilarginae) from the Gulf of Thailand. Zootaxa 5071 (4): 537-562, DOI: https://doi.org/10.11646/zootaxa.5071.4.4
6050E603155AFF9AFF2E83CFF657FEEC.taxon	discussion	Remarks. Ancistrosyllis nakkaritae sp. nov. belongs to the second group of species in the genus Ancistrosyllis characterized by the presence of both a median antenna and two lateral antennae. It mostly resembles A. fioronii Fiege & Böggemann, 1999 and A. kornkanokae sp. nov. of this group by having the first dorsal cirri start from chaetiger 1, the absence of eyespots and first notopodial hooks begin at chaetiger 3 (Table 1). Ancistrosyllis nakkaritae sp. nov. differs from A. fioronii and A. kornkanokae sp. nov. in having the first ventral cirri from chaetiger 1 instead chaetiger 2 as in A. fioronii (Fiege & Böggemann 1999) and chaetiger 3 in A. kornkanokae sp. nov .. Moreover, the lateral antennae and tentacular cirri in A. nakkaritae sp. nov. are longer than those of A. fioronii and A. kornkanokae sp. nov., and the median antenna in A. nakkaritae sp. nov. is conspicuously smaller. A. nakkaritae sp. nov. also differs from A. fioronii by having two types of neurochaetae and a higher A. carolinensis Gar- Western Atlantic, North Absent Globular tentacular 1 2 6 Low, rounded Rounded or trun- Gardiner 1976 diner, 1976 Carolina to the Gulf of cirri cate, Mexico conical retractile acicular lobes A. falcata Day, 1957 South Africa, Inhaca Present Fusiform, papillose 1 1 7 Reduced Truncate, bent Day 1957 Island tentacular cirri downwards A. hamata Hartman, Pacific Ocean, Southern Absent Short, subequal 1 3 4 – 7 Short, rounded Short, truncate, Hartman 1960 1960 California tentacular cirri longer than notopodia A. matlaensis Mandal & R. Matla, Sundarban Absent Conical, papillose 1 2 7 Reduced Truncate, straight Mandal & Deb Deb, 2018 Estuarine System, India tentacular cirri 2018 A. papillosa Jones, 1961 Florida, intertidal Present Long tentacular cirri 1 3 3 Reduced Conical, well devel- Jones 1961 (longer than palps) oped number of neurochaetae per fascicle than A. fioronii with up to 12 chaetae per bundle while A. fioronii has only a single type neurochaeta with 4 – 6 chaetae per bundle (Fiege & Böggemann 1999). Furthermore, A. nakkaritae sp. nov. also differs from A. kornkanokae sp. nov. by all neurochaetae with bifid tips, papillae on the body surface and the parapodia are numerous and longer and larger. The neurochaetae of A. kornkanokae sp. nov. are unidentate and the papillae on the body surface are smaller than in A. nakkaritae.	en	Plathong, Jintana, Dean, Harlan K., Plathong, Sakanan (2021): Four new species of Pilargidae (Annelida: Pilarginae) from the Gulf of Thailand. Zootaxa 5071 (4): 537-562, DOI: https://doi.org/10.11646/zootaxa.5071.4.4
6050E603155CFF9AFF2E82CAF793FD60.taxon	diagnosis	Diagnosis. (after Glasby & Salazar-Vallejo 2021). Pilargids with body cylindrical, integument with few verrucae, larger and more numerous in anterior and posterior ends. Median antenna absent, lateral antennae papilliform. Palps unfused, biarticulated, palpostyle minute. Paired ventrolateral palpal papillae present. Pharynx lacking terminal papillae; proximally with soft papillae or hardened denticles arranged in rows. Two pairs of tentacular cirri, minute. Deep constriction between the first segment and the first chaetiger. Dorsal and ventral cirri papilliform; the latter from chaetigers 1 or 3. Notochaetae are hooks, from chaetigers 6 to 8. Neurochaetae are a variety of capillaries, limbate or nonlimbate, smooth or finely serrated.	en	Plathong, Jintana, Dean, Harlan K., Plathong, Sakanan (2021): Four new species of Pilargidae (Annelida: Pilarginae) from the Gulf of Thailand. Zootaxa 5071 (4): 537-562, DOI: https://doi.org/10.11646/zootaxa.5071.4.4
6050E603155CFF87FF2E852DF1F8FD5C.taxon	description	Figs 9 – 12	en	Plathong, Jintana, Dean, Harlan K., Plathong, Sakanan (2021): Four new species of Pilargidae (Annelida: Pilarginae) from the Gulf of Thailand. Zootaxa 5071 (4): 537-562, DOI: https://doi.org/10.11646/zootaxa.5071.4.4
6050E603155CFF87FF2E852DF1F8FD5C.taxon	materials_examined	Material examined. Eight specimens, collected from Songkhla Sea, the Gulf of Thailand, Western Pacific. Coll. MEM (Marine Ecosearch Management Co., Ltd.), mud mixed with sand and shells. Holotype: PSUZC-POL- 0338 (1 spec.), S 09 - 5 (7 ° 32 ’ 01 ” N, 100 ° 42 ’ 30 ” E), 17 Aug 2018, 24.0 m. Paratypes: PSUZC-POL- 0339 (1 spec.), S 14 (7 ° 26 ’ 14 ” N, 100 ° 36 ’ 13 ” E), 5 Mar 2014, 15.5 m; PSUZC-POL- 0340 (1 spec.), S 18 - 1 (7 ° 21 ’ 38 ” N, 100 ° 37 ’ 01 ” E), 3 Jun 2015, 16.0 m; PSUZC-POL- 0341 (1 spec.), S 18 - 2 (7 ° 21 ’ 34 ” N, 100 ° 37 ’ 06 ” E), 3 Jun 2015, 16 m; PSUZC-POL- 0342 (1 spec.), S 09 - 3 (7 ° 32 ’ 01 ” N, 100 ° 42 ’ 42 ” E), 2 Mar 2016, 24.0 m; PSUZC-POL- 0343 (2 specs., 1 on SEM stub), S 08 (7 ° 29 ’ 10 ” N, 100 ° 47 ’ 06 ” E), 18 May 2016, 25.0 m; PSUZC-POL- 0344 (1 spec.), S 09 - 1 (7 ° 32 ’ 13 ” N, 100 ° 42 ’ 42 ” E), 17 Aug 2018, 24.0 m. Type locality. Songkhla Sea, Gulf of Thailand (Fig. 1 C).	en	Plathong, Jintana, Dean, Harlan K., Plathong, Sakanan (2021): Four new species of Pilargidae (Annelida: Pilarginae) from the Gulf of Thailand. Zootaxa 5071 (4): 537-562, DOI: https://doi.org/10.11646/zootaxa.5071.4.4
6050E603155CFF87FF2E852DF1F8FD5C.taxon	diagnosis	Diagnosis. Cabira saithipae sp. nov. is characterized by the presence of minute papilliform lateral antennae and tentacular cirri, the lack of a median antenna, and dorsal and ventral cirri beginning on chaetiger 1. Notopodial hooks occur from chaetiger 8. Three types of neurochaetae in the anterior parapodia: long, slender, non-limbate chaeta, short, broad chaeta with strongly recurved tips, and short, broad chaeta with curved tips.	en	Plathong, Jintana, Dean, Harlan K., Plathong, Sakanan (2021): Four new species of Pilargidae (Annelida: Pilarginae) from the Gulf of Thailand. Zootaxa 5071 (4): 537-562, DOI: https://doi.org/10.11646/zootaxa.5071.4.4
6050E603155CFF87FF2E852DF1F8FD5C.taxon	description	Description. Holotype largest specimen, incomplete, 11.1 mm long and 0.46 mm wide, for about 64 chaetigers. One paratype complete with one anal cirri (other anal cirri broken), about 50 chaetigers, 7.2 mm long and 0.3 mm wide. Other paratypes incomplete, 15 – 38 chaetigers, 1.8 – 6.6 mm long, 0.2 – 0.4 mm wide. Body whitish, papillose and annulated. Holotype, present large conical papillae at dorsal and ventral of chaetigers 7 – 17 (Fig. 9 A, D). Prostomium bilobed, short, broad, wider than long. Median antenna and eyespots absent; palps small, paired minute ventrolateral palpal papillae. One pair of small, short, button-like lateral antennae, basally papillose (Figs 9 A – B, 10 A – C, 12 A). Pair of nuchal organs on the posterolateral margin of the prostomium (Fig. 10 C). Peristomium fused with prostomium, two pairs of small basally papillose, conical, tentacular cirri inserted laterally (Figs 10 A – C, 12 A). Proboscis not everted in holotype, everted in smallest paratype with rows of denticles (Fig. 9 C). Dorsal tentacular cirri slightly longer than ventral cirri (Fig. 10 E – F). Dorsal and ventral cirri are small, papilliform, from first chaetiger. Parapodia sub-biramous, reduced; notopodial lobes reduced with small dorsal cirrus similar in size throughout. Notopodia with single acicula and 1 – 2 notopodial hooks. First notopodial hooks start at chaetiger 8 in all specimens; hooks small with strongly curved tip (Figs 11 B, 12 A). Neuropodia reduced, very short with acicular lobe. Anterior chaetigers from chaetiger 2 – 17 (chaetiger 2 – 21 in one paratype) with three types of neurochaetae: 1) long, slender, non-limbate chaeta with subdistally foliose, finely denticulate, tip falcate, 2) short chaeta with strong recurved tip and 3) short chaeta with curved tips; about 4 – 6 chaetae per fascicle; 3 at upper acicular lobe and 3 at the lower acicular lobe. Each parapodia with 1 – 2 short strong recurved chaetae, 1 – 3 short slightly recurved chaetae, and 2 – 3 long, slender, non-limbate chaetae (Figs 11 A – F, 12 B – C). Two types of neurochaetae from chaetiger 18 – 26 or 27, lacking the short broad chaeta with strongly recurved tip, each with four chaetae per fascicle; one short, narrow chaeta with curved tips and 3 non-limbate capillary chaetae; from chaetiger 28 to posterior parapodia, neuropodia with three capillary chaetae; one long chaeta, longer about twice the length of short ones and two short chaetae, length almosty equal. Pygidium with two anal cirri (0.05 mm long). Reproduction. Holotype and paratype were collected in August 2018, body with eggs (Fig. 9 E).	en	Plathong, Jintana, Dean, Harlan K., Plathong, Sakanan (2021): Four new species of Pilargidae (Annelida: Pilarginae) from the Gulf of Thailand. Zootaxa 5071 (4): 537-562, DOI: https://doi.org/10.11646/zootaxa.5071.4.4
6050E603155CFF87FF2E852DF1F8FD5C.taxon	etymology	Etymology. The new species name is honor to Miss Kanoknapat (Saithip) Plathong, older sister of Sakananauthor. Habitat. Found at 16 – 25 m depth, in mud mixed with sand and shells.	en	Plathong, Jintana, Dean, Harlan K., Plathong, Sakanan (2021): Four new species of Pilargidae (Annelida: Pilarginae) from the Gulf of Thailand. Zootaxa 5071 (4): 537-562, DOI: https://doi.org/10.11646/zootaxa.5071.4.4
6050E603155CFF87FF2E852DF1F8FD5C.taxon	distribution	Distribution. Only known from type locality - Songkhla Sea, Gulf of Thailand.	en	Plathong, Jintana, Dean, Harlan K., Plathong, Sakanan (2021): Four new species of Pilargidae (Annelida: Pilarginae) from the Gulf of Thailand. Zootaxa 5071 (4): 537-562, DOI: https://doi.org/10.11646/zootaxa.5071.4.4
6050E603155CFF87FF2E852DF1F8FD5C.taxon	discussion	Remarks. Cabira saithipae sp. nov. belongs to the second group (Group II) of Cabira species which have more than one type of chaetae (Table 2). It mostly resembles C. brevicirris Rangarajan, 1964 from Palk Bay, Southern India which also has long non-limbate chaetae, short chaetae with strong recurved tips, and short chaetae with curved tips. However, C. saithipae sp. nov. differs from C. brevicirris by having all three types of neurochaetae in antererior chaetigers from chaetiger 2 to 17 – 21, while C. brevicirris has only two types of neurochaetae beginning at chaetigers 4 – 13 (Rangarajan 1964; Mandal et al. 2007). In addition, Cabira saithipae sp. nov. has large conical papillae on the posterior edge of the annulations from chaetigers 7 – 17 both dorsally and ventrally. These conical papillae are absent in C. brevicirris which has mainly square papillae. Moreover, the appearance of the first ventral cirri and the first notopodial hooks in C. saithipae sp. nov. occurs at chaetiger 1 and chaetiger 8, respectively while the first ventral cirri of C. brevicirris, begin at chaetiger 1 or 3 and the first notopodial hooks occurs at chaetiger 6 – 8 (Rangarajan 1964). Cabira saithipae sp. nov. also differs from C. thailandica sp. nov. in that there are three types of neurochaetae and bidentate tipped chaetae are lacking while C. thailandica sp. nov. has only a single type of neurochaetae with bidentate tips. Additionally, the first ventral cirri and first notopodial hooks begin at chaetiger 1 and 8, respectively in C. saithipae sp. nov. while they begin at chaetiger 3 and 7 in C. thailandica sp. nov. (Table 2).	en	Plathong, Jintana, Dean, Harlan K., Plathong, Sakanan (2021): Four new species of Pilargidae (Annelida: Pilarginae) from the Gulf of Thailand. Zootaxa 5071 (4): 537-562, DOI: https://doi.org/10.11646/zootaxa.5071.4.4
6050E6031541FF8CFF2E801AF4A1FD04.taxon	description	Figs 13 – 15	en	Plathong, Jintana, Dean, Harlan K., Plathong, Sakanan (2021): Four new species of Pilargidae (Annelida: Pilarginae) from the Gulf of Thailand. Zootaxa 5071 (4): 537-562, DOI: https://doi.org/10.11646/zootaxa.5071.4.4
6050E6031541FF8CFF2E801AF4A1FD04.taxon	materials_examined	Material examined. 76 specimens, collected from the Songkhla Sea, Gulf of Thailand, Western Pacific. Coll. MEM (Marine Ecosearch Management Co., Ltd.) mud mixed with sand and shells. Details of geographic positions and environmental characteristics of sampling stations are in Table 2. Holotype: PSUZC-POL- 0200 (1 spec.), S 52 (7 ° 42 ’ 05 ” N, 100 ° 40 ’ 15 ” E), 11 Feb 2015, 23.0 m. Paratypes: PSUZC-POL- 0201 (1 spec.), S 09 - 10 (7 ° 31 ’ 56 ” N, 100 ° 42 ’ 47 ” E), 3 Jul 2014, 24.3 m; PSUZC-POL- 0202 (1 spec.), S 09 - 6 (7 ° 32 ’ 13 ” N, 100 ° 42 ’ 21 ” E), 20 Feb 2015, 23.6 m; PSUZC-POL- 0203 (1 spec.), S 02 (7 ° 31 ’ 44 ” N, 100 ° 28 ’ 15 ” E), 5 Feb 2015, 10.0 m; PSUZC-POL- 0204 (7 specs., 4 specs. on SEM stubs), S 03 (7 ° 21 ’ 02 ” N, 100 ° 31 ’ 45 ” E), 2 Dec 2015, 9.0 m; PSUZC-POL- 0205 (1 spec.), S 46 (7 ° 40 ’ 58 ” N, 100 ° 29 ’ 39 ” E), 22 Feb 2015, 14.5 m; PSUZC-POL- 0206 (1 spec.), S 19 (7 ° 21 ’ 01 ” N, 100 ° 36 ’ 54 ” E), 17 Jul 2015, 14.0 m; PSUZC-POL- 0207 (1 spec.), S 08 (7 ° 29 ’ 10 ” N, 100 ° 47 ’ 06 ” E), 16 Mar 2016, 25.0 m; PSUZC- POL- 0208 (1 spec.), S 14 (7 ° 26 ’ 14 ” N, 100 ° 36 ’ 13 ” E), 20 Sep 2017, 15.5 m; PSUZC-POL- 0209 (1 spec.), S 11 - 2 (7 ° 31 ’ 01 ” N, 100 ° 36 ’ 39 ” E), 27 Mar 2017, 18.9 m; PSUZC-POL- 0210 (1 spec.), S 11 - 9 (7 ° 31 ’ 11 ” N, 100 ° 36 ’ 18 ” E), 27 Mar 2017, 18.7 m; PSUZC-POL- 0211 (1 spec.), S 10 - 8 (7 ° 28 ’ 44 ” N, 100 ° 36 ’ 11 ” E), 5 May 2018, 18.5 m; PSUZC-POL- 0212 (1 spec.), S 09 - 3 (7 ° 32 ’ 01 ” N, 100 ° 42 ’ 41 ” E), 16 Aug 2018, 24.0 m; AM W. 52912 (1 spec.), S 05 (7 ° 34 ’ 03 ” N, 100 ° 33 ’ 57 ” E), 13 Oct 2015, 16.5 m; AM W. 52913 (1 spec.), S 06 (7 ° 20 ’ 10 ” N, 100 ° 36 ’ 59 ” E), 13 Oct 2015, 15.5 m. Additional Material. S 02 (7 ° 31 ’ 44 ” N, 100 ° 28 ’ 15 ” E), 6 May 2014 (3 specs.), 21 May 2015 (1 spec.), 10 m; S 03 (7 ° 21 ’ 02 ” N, 100 ° 31 ’ 45 ” E), 6 May 2014 (1 spec.), 2 Dec 2015 (6 specs.), 13 Oct 2015 (1 spec.), 9.0 m; S 04 (7 ° 49 ’ 22 ” N, 100 ° 29 ’ 11 ” E), 20 May 2015 (2 specs.), 14 Oct 2015 (1 spec.), 17.5 m; S 05 (7 ° 34 ’ 03 ” N, 100 ° 33 ’ 57 ” E), 6 May 2014 (4 specs.), 21 May 2015 (5 specs.), 13 Oct 2015 (3 specs.), 2 Dec 2015 (2 specs.), 15 Mar 2016 (1 spec.), 18 Oct 2016 (1 spec.), 16.5 m; S 06 (7 ° 20 ’ 10 ” N, 100 ° 36 ’ 59 ” E), 6 May 2014 (2 specs.), 10 Sep 2014 (1 spec.), 2 Dec 2015 (1 spec.), 15 May 2016 (1 spec.), 17 May 2016 (1 spec.), 15.5 m; S 07 (7 ° 44 ’ 01 ” N, 100 ° 43 ’ 02 ” E), 6 May 2014 (1 spec.), 26 Jan 2015 (2 specs.), 14 Oct 2015 (3 specs.), 18 May 2016 (2 specs.), 26.5 m; S 08 (7 ° 29 ’ 10 ” N, 100 ° 47 ’ 06 ” E), 16 Mar 2016 (1 spec.), 18 May 2016 (1 spec.), 19 Oct 2016 (1 spec.), 25.0 m; S 09 - 3 (7 ° 32 ’ 01 ” N, 100 ° 42 ’ 41 ” E), 2 Mar 2016 (1 spec.), 24.0 m; S 09 - 7 (7 ° 32 ’ 19 ” N, 100 ° 42 ’ 24 ” E), 1 Mar 2016 (1 spec.), 23.7 m; S 10 - 4 (7 ° 28 ’ 14 ” N, 100 ° 36 ’ 39 ” E), 15 Feb 2015 (1 spec.), 19.0 m; S 14 (7 ° 26 ’ 13 ” N, 100 ° 36 ’ 12 ” E), 20 Feb 2015 (3 specs.), 15.5 m; S 17 (7 ° 36 ’ 16 ” N, 100 ° 34 ’ 48 ” E), 7 Oct 2015 (2 specs.), 18.0 m; S 18 - 1 (7 ° 21 ’ 38 ” N, 100 ° 37 ’ 01 ” E), 3 Jun 2015 (4 specs.), 16.0 m; S 18 - 2 (7 ° 21 ’ 34 ” N, 100 ° 37 ’ 06 ” E), 3 Jun 2015 (2 specs.), 16.0 m; S 19 (7 ° 21 ’ 01 ” N, 7 ° 21 ’ 01 ” E), 17 Jul 2015 (5 specs.), 14.0 m; S 21 (7 ° 33 ’ 16 ” N, 100 ° 46 ’ 43 ” E), 17 Feb 2015 (1 spec.), 24.0 m; S 23 (7 ° 49 ’ 20 ” N, 100 ° 33 ’ 17 ” E), 14 Jul 2015 (3 specs.), 20.5 m; S 25 (7 ° 16 ’ 28 ” N, 100 ° 48 ’ 46 ” E), 13 Jul 2015 (1 spec.), 6 Oct 2015 (1 spec.), 22.0 m; S 38 (7 ° 37 ’ 29 ” N, 100 ° 42 ’ 53 ” E), 3 Jun 2015 (3 specs.), 22.0 m; S 40 (7 ° 26 ’ 50 ” N, 100 ° 44 ’ 49 ” E), 26 Sep 2011 (1 spec.), 21.0 m; S 45 (7 ° 47 ’ 46 ” N, 100 ° 28 ’ 10 ” E), 22 Feb 2015 (1 spec.), 14.3 m; S 47 (7 ° 34 ’ 04 ” N, 100 ° 31 ’ 37 ” E), 22 Feb 2015 (11 specs.), 14.0 m; S 48 (7 ° 47 ’ 38 ” N, 100 ° 42 ’ 29 ” E), 22 Feb 2015 (1 spec.), 24.6 m; S 50 (7 ° 35 ’ 01 ” N, 100 ° 46 ’ 58 ” E), 21 Feb 2015 (2 specs.), 22.5 m; S 53 (7 ° 27 ’ 59 ” N, 100 ° 31 ’ 47 ” E), 23 Feb 2015 (1 spec.), 14.3 m. Type locality. Songkhla Sea, Gulf of Thailand (Fig. 1 D).	en	Plathong, Jintana, Dean, Harlan K., Plathong, Sakanan (2021): Four new species of Pilargidae (Annelida: Pilarginae) from the Gulf of Thailand. Zootaxa 5071 (4): 537-562, DOI: https://doi.org/10.11646/zootaxa.5071.4.4
6050E6031541FF8CFF2E801AF4A1FD04.taxon	diagnosis	Diagnosis. Cabira thailandica sp. nov. is characterized by the presence of minute papilliform lateral antennae and tentacular cirri; median antenna absent; dorsal cirri begin on chaetiger 1 and ventral cirri from chaetiger 3. Notopodial hooks occur from chaetiger 7. Single type of neurochaetae, long, slender, non-limbate capillary chaeta with bidentate tips.	en	Plathong, Jintana, Dean, Harlan K., Plathong, Sakanan (2021): Four new species of Pilargidae (Annelida: Pilarginae) from the Gulf of Thailand. Zootaxa 5071 (4): 537-562, DOI: https://doi.org/10.11646/zootaxa.5071.4.4
6050E6031541FF8CFF2E801AF4A1FD04.taxon	description	Description. A small species, holotype complete, 14.4 mm long and 0.3 mm wide for 53 chaetigers. Body papillose, whitish, transparent with brown and light tan eggs visible in the body cavity, widest anteriorly. Paratypes, one complete about 48 chaetigers (13.8 mm long, 0.9 mm wide), one with the last six chaetigers regenerating (350 μm long, 126 μm wide), no hooks present in the regenerating region but with two small digitate anal cirri about 57 μm long (others incomplete, 1.6 – 21.1 mm long, 0.37 – 0.74 mm wide with 14 – 80 segments). Prostomium bilobed, short, broad, wider than long (163 µm length and 355 µm wide); median antenna and eyespots absent. One pair of lateral antennae; short, small, conical and papillose. Palps posterior on prostomium with longitudinal folds. Pair of nuchal organs on the posterolateral margin of the prostomium (Fig. 13 C). Peristomium fuse with prostomium, two pairs of short, conical, papillose tentacular cirri insert laterally (Fig. 11 A – C). Dorsal tentacular cirri slightly shorter than ventral cirri. Parapodia sub-biramous; notopodia reduced, each with very short papillated dorsal cirri, single acicular, and strongly curved notopodial hooks start from chaetiger 7 (Figs 13 A – B, 14 B, 15 A – B). Dorsal cirri present from first chaetiger, continue throughout body. Ventral cirri present from chaetiger 3 (Fig. 13 A). Neuropodia short, reduced, all long narrow, non - limbate capillary chaetae with bidentate tips, vary in length, up to six chaetae per fascicle (Figs 14 A, B, D, E, 15 C). Pygidium with two long, digitate and papillose anal cirri.	en	Plathong, Jintana, Dean, Harlan K., Plathong, Sakanan (2021): Four new species of Pilargidae (Annelida: Pilarginae) from the Gulf of Thailand. Zootaxa 5071 (4): 537-562, DOI: https://doi.org/10.11646/zootaxa.5071.4.4
6050E6031541FF8CFF2E801AF4A1FD04.taxon	etymology	Etymology. The new species is named after Thailand, the country where the specimens were collected. Habitat. Found at 10 – 27 m depth, in mud mixed with sand and shells.	en	Plathong, Jintana, Dean, Harlan K., Plathong, Sakanan (2021): Four new species of Pilargidae (Annelida: Pilarginae) from the Gulf of Thailand. Zootaxa 5071 (4): 537-562, DOI: https://doi.org/10.11646/zootaxa.5071.4.4
6050E6031541FF8CFF2E801AF4A1FD04.taxon	distribution	Distribution. Widely present in the Songkhla Sea, Gulf of Thailand, Western Pacific.	en	Plathong, Jintana, Dean, Harlan K., Plathong, Sakanan (2021): Four new species of Pilargidae (Annelida: Pilarginae) from the Gulf of Thailand. Zootaxa 5071 (4): 537-562, DOI: https://doi.org/10.11646/zootaxa.5071.4.4
6050E6031541FF8CFF2E801AF4A1FD04.taxon	discussion	Remarks. Cabira thailandica sp. nov. is characterized by the absence of both eyespots and a median antenna, the presence of two short, papillate lateral antennae, dorsal cirri from the first chaetiger, ventral cirri from chaetiger 3 and notopodial hooks from chaetiger 7. All neurochaetae are narrow, non - limbate chaetae with bidentate tips. It belongs to group I of Cabira species by having only a single type of neurochaetae (Table 2). Cabira thailandica sp. nov. resembles C. incerta Webster, 1879 from Western Atlantic and C. rangarajani Mandal, Harkantra & Salazar - Vallejo, 2007 from Indian Ocean (Arabian Sea) in that all three species have a single type of neurochaetae and the first notopodial hooks beginning on chaetiger 7 (Webster 1879; Mandal et al. 2007). However, C. thailandica sp. nov. can be distinguished from C. incerta and C. rangarajani by having bidentate neurochaetae which are lacking in C. incerta and C. rangarajani. Cabira thailandica sp. nov. differs from C. saithipae sp. nov. by having a single type of long, non - limbate chaeta with bidentate tips, the first ventral cirri occur at chaetiger 3 and first notopodial hooks begin on chaetiger 7. Cabira saithipae sp. nov. has three types of neurochaetae, ventral cirri begin at chaetiger 1 and notopodial hooks start from chaetiger 8.	en	Plathong, Jintana, Dean, Harlan K., Plathong, Sakanan (2021): Four new species of Pilargidae (Annelida: Pilarginae) from the Gulf of Thailand. Zootaxa 5071 (4): 537-562, DOI: https://doi.org/10.11646/zootaxa.5071.4.4
