taxonID	type	description	language	source
0637D00515480B4FFF3873D6E7DCFE35.taxon	description	(Fig. 2 A – F, Table 3) http: // zoobank. org / urn: lsid: zoobank. org: act: 1 D 5772 C 8 - 99 E 4 - 40 B 7 - ADA 6 - DF 404 C 2 F 1 D 0 D	en	Boonzaaier-Davids, Melissa K., Ma, Kevin C. K., Mcquaid, Christopher D. (2023): Epibiotic association of encrusting cheilostome bryozoans on shells of an invasive mussel from rocky shores of South Africa, with the description of a new aviculiferous species of Chaperia. Zootaxa 5258 (2): 197-210, DOI: 10.11646/zootaxa.5258.2.2, URL: http://dx.doi.org/10.11646/zootaxa.5258.2.2
0637D00515480B4FFF3873D6E7DCFE35.taxon	materials_examined	Material examined. Holotype: SAMC-A 094514 (dry), Seagulls (32 ° 38 ′ 31.0 ″ S, 28 ° 25 ′ 41.5 ″ E), 8 March 2020. Paratype: SAMC-A 094513, same details as the holotype. Other non-type specimens: SAMC-A 094511, Tenza Beach (32 ° 22 ′ 37.8 ″ S, 28 ° 45 ′ 06.2 ″ E), 29 January 2020. SAMC-A 094508 (on the same substratum as C. hyalina), SAMC- A 094509 (on the same substratum as C. hyalina), SAMC-A 094512, Kei Mouth (32 ° 41 ′ 03.4 ″ S, 28 ° 22 ′ 59.3 ″ E), 30 January 2020. SAMC-A 094515 - 18, Kidds Beach (33 ° 08 ′ 57.3 ″ S 27 ° 42 ′ 09.2 ″ E), 7 March 2020. SAMC-A 094520 - 25, Schoenmakerskop (34 ° 02 ′ 27.4 ″ S, 25 ° 31 ′ 59.5 ″ E), 5 August 2020. SAMC-A 094528, St. Francis Bay (34 ° 10 ′ 15.7 ″ S, 24 ° 50 ′ 06.2 ″ E), 4 August 2020. SAMC-A 094630 - 34, Jeffreys Bay (34 ° 01 ′ 35.5 ″ S, 24 ° 55 ′ 52.2 ″ E), 3 August 2020. All material was collected by K. C. K. Ma and is kept dry. Additional comparative material examined: Chaperia capensis (Busk, 1884), SAMC-A 026485, station SM 179 (33 ° 30.3 ′ S, 27 ° 22.1 ′ E), off Great Fish River Mouth, Southeast Coast, South Africa, dredged, depth 80 m, 29 May 1978. Chaperia septispina Florence, Hayward & Gibbons, 2007, SAMC-A 028571, Homestead Plateau, Oudekraal (33 ° 58 ′ 90 ″ S, 17 ° 15 ′ 00 ″ E), depth 12 m, collected by W. Florence, 30 April 1999.	en	Boonzaaier-Davids, Melissa K., Ma, Kevin C. K., Mcquaid, Christopher D. (2023): Epibiotic association of encrusting cheilostome bryozoans on shells of an invasive mussel from rocky shores of South Africa, with the description of a new aviculiferous species of Chaperia. Zootaxa 5258 (2): 197-210, DOI: 10.11646/zootaxa.5258.2.2, URL: http://dx.doi.org/10.11646/zootaxa.5258.2.2
0637D00515480B4FFF3873D6E7DCFE35.taxon	etymology	Etymology. From the Latin a- plus typica, meaning atypical, not usual, and referring to the atypical diagnostic features noted in this new Chaperia compared to other species of the genus.	en	Boonzaaier-Davids, Melissa K., Ma, Kevin C. K., Mcquaid, Christopher D. (2023): Epibiotic association of encrusting cheilostome bryozoans on shells of an invasive mussel from rocky shores of South Africa, with the description of a new aviculiferous species of Chaperia. Zootaxa 5258 (2): 197-210, DOI: 10.11646/zootaxa.5258.2.2, URL: http://dx.doi.org/10.11646/zootaxa.5258.2.2
0637D00515480B4FFF3873D6E7DCFE35.taxon	diagnosis	Diagnosis. Colony encrusting. Cryptocyst typically granular, extensive; gymnocyst reduced or absent. Suborificial occlusor laminae well-developed. Spines on distal rim. Interzooidal avicularia and vestigial ooecia present. Pore chamber windows present.	en	Boonzaaier-Davids, Melissa K., Ma, Kevin C. K., Mcquaid, Christopher D. (2023): Epibiotic association of encrusting cheilostome bryozoans on shells of an invasive mussel from rocky shores of South Africa, with the description of a new aviculiferous species of Chaperia. Zootaxa 5258 (2): 197-210, DOI: 10.11646/zootaxa.5258.2.2, URL: http://dx.doi.org/10.11646/zootaxa.5258.2.2
0637D00515480B4FFF3873D6E7DCFE35.taxon	description	Description. Colony encrusting, unilaminar, multiserial, usually forming small patches, some colonies up to 30 mm in diameter (see Table 2). Dried (unbleached) material light brown to creamy white. Autozooids arranged quincuncially (Fig. 2 A), rounded distally, widest at one third to half zooidal length, with a pair of distal and one lateral pore chamber windows, approximately at autozooid mid-length (Fig. 2 B). Cryptocyst well-developed, occupying nearly the total length of autozooid, a raised rim outlining the autozooids, sometimes with the distal part of the opesia raised; frontal surface granular, grain size 4 – 12 μm in diameter (N T = 60). Reduced or negligible gymnocyst. Opesia eye-shaped with a pair of well-developed occlusor laminae (Fig. 2 C); 6 – 8 oral spines, more commonly seven (N T = 20; length range = 0.17 – 0.35 mm; 12 – 28 μm in diameter) distributed evenly around the distal part of the opesia in a shallow arc (Fig. 2 E), ending more or less at level with the proximal border of the opesia. Interzooidal avicularia present, twinned or single, each situated disto-medially, projecting into the next distal zooid, distally directed, oval-shaped, the rostrum rounded, with condyles as mandibular pivots (Fig. 2 D), more or less situated mid-length of the avicularium. Intramural budding observed (Fig. 2 D). Ooecia as a transversely narrow rim on the distal border of opesia with ooecial pore located medio-distally (Fig. 2 E, F). Ancestrula not seen.	en	Boonzaaier-Davids, Melissa K., Ma, Kevin C. K., Mcquaid, Christopher D. (2023): Epibiotic association of encrusting cheilostome bryozoans on shells of an invasive mussel from rocky shores of South Africa, with the description of a new aviculiferous species of Chaperia. Zootaxa 5258 (2): 197-210, DOI: 10.11646/zootaxa.5258.2.2, URL: http://dx.doi.org/10.11646/zootaxa.5258.2.2
0637D00515480B4FFF3873D6E7DCFE35.taxon	discussion	Remarks. This species is confidently placed in the genus Chaperia due to the presence of the eye-shaped opesia not exceeding 50 % of the zooidal length, extensive cryptocyst, stout spines around the distal oral border and well-developed occlusor laminae as described in Gordon (1982). Avicularia and ovicells were not reported in the original genus description by Jullien (1881) and subsequent observations made by Gordon (1982). However, interzooidal avicularia and vestigial ooecia were recently observed in some Chaperia species from New Zealand (D. P. Gordon, personal communication, 27 July 2022). These features differ from those of Chaperiopsis species that have an oval opesia generally occupying 75 % or more of the zooidal length, narrow cryptocyst, negligible occlusor laminae and the presence of frequent small avicularia and prominent hyperstomial ovicells (Gordon 1982). Chaperia acanthina Lamouroux, 1824 (C. australis Jullien, 1881 by original designation, p. 62), originally described from Falkland Islands in the South Atlantic, was also reported from South Africa (O’Donoghue & de Watteville 1937; O’Donoghue 1957; Hayward 1980). Chaperia atypica n. sp. differs from this species in the shape of the opesia, in the position and number of spines, and in having a reduced gymnocyst. However, records of C. acanthina in South Africa are in need of revision (D. P. Gordon, personal communication, 13 September 2022) and also discussed in Hayward & Cook (1983, p. 19). Two species of Chaperia are known from South Africa, namely C. capensis and C. septispina. An additional species, C. polygonia Kluge, 1914 is known from Antarctica in the Southern Ocean. Chaperia atypica n. sp. has 6 – 8 distolateral spines, while C. acanthina has 4 – 5 distal spines, C. polygonia 5 – 6, C. septispina 5 – 7 and C. capensis only two. This new species is the first Chaperia with avicularia and the first South African species with ooecia. Four out of nine C. atypica n. sp. colonies examined using SEM (SAMC-A 094513, SAMC-A 094516, SAMC-A 094524 and SAMC-A 094525), indicated the presence of avicularia, usually one or two interzooidal avicularia scattered sporadically in a colony of at least 20 autozooids. One colony (SAMC-A 094513), with at least 40 autozooids, had four autozooids associated with a single interzooidal avicularium, and one associated with twinned avicularia (see Fig. 2 D). These avicularia differ in shape and frequency from those in Chaperiopsis: they are rare and with rounded rostra (Fig. 2 D), as opposed to the frequent avicularia with triangular rostra and pedunculate avicularia usually present for example in Chaperiopsis multifida (Busk, 1884), a species reported from South Africa (e. g. Marcus 1922; O’Donoghue & de Watteville 1935; Hayward & Cook 1983; Florence et al. 2007) and also New Zealand (Gordon 1984). Vestigial ooecia (as seen in Fig. 2 E, F) have also been reported from an Australian Chaperia sp. (see Cook et al. 2018, p. 107, fig. 3.44 A) and are likely to be typical of the genus but previously overlooked. To date, this species has only been observed forming encrusting patches on the invasive mussel M. galloprovincialis, distributed on rocky shores from Tenza Beach to St. Francis Bay on the southeast coast of South Africa.	en	Boonzaaier-Davids, Melissa K., Ma, Kevin C. K., Mcquaid, Christopher D. (2023): Epibiotic association of encrusting cheilostome bryozoans on shells of an invasive mussel from rocky shores of South Africa, with the description of a new aviculiferous species of Chaperia. Zootaxa 5258 (2): 197-210, DOI: 10.11646/zootaxa.5258.2.2, URL: http://dx.doi.org/10.11646/zootaxa.5258.2.2
0637D005154D0B4DFF387601E625FE11.taxon	description	(Fig. 3 A – C, Table 4)	en	Boonzaaier-Davids, Melissa K., Ma, Kevin C. K., Mcquaid, Christopher D. (2023): Epibiotic association of encrusting cheilostome bryozoans on shells of an invasive mussel from rocky shores of South Africa, with the description of a new aviculiferous species of Chaperia. Zootaxa 5258 (2): 197-210, DOI: 10.11646/zootaxa.5258.2.2, URL: http://dx.doi.org/10.11646/zootaxa.5258.2.2
0637D005154D0B4DFF387601E625FE11.taxon	materials_examined	Material examined. SAMC-A 094507, Morgan Bay (32 ° 42 ′ 41.1 ″ S, 28 ° 20 ′ 21.7 ″ E), 10 December 2019. SAMC- A 094508 - 09, Kei Mouth (32 ° 41 ′ 03.4 ″ S, 28 ° 22 ′ 59.3 ″ E), 10 – 11 December 2019. SAMC-A 094510, Mazeppa Bay (32 ° 28 ′ 25.0 ″ S, 28 ° 39 ′ 25.5 ″ E), 28 January 2020. SAMC-A 094518 (on the same substratum as C. atypica n. sp.) (dry), Kidds Beach (33 ° 08 ′ 57.3 ″ S, 27 ° 42 ′ 09.2 ″ E), 7 March 2020. SAMC-A 094526 - 27, SAMC-A 094528 (on the same substratum as C. atypica n. sp.), St. Francis Bay (34 ° 10 ′ 15.7 ″ S, 24 ° 50 ′ 06.2 ″ E), 4 August 2020. SAMC- A 094519, Mossel Bay (34 ° 10 ′ 52.4 ″ S, 22 ° 09 ′ 29.1 ″ E), 26 March 2020. All material was collected by K. C. K. Ma and is kept dry. Additional comparative material examined: Celleporella hyalina, SAMC-A 073500 (preserved in ethanol), False Bay, rock dredge, collected by J. Gilchrist, 31 January 1959.	en	Boonzaaier-Davids, Melissa K., Ma, Kevin C. K., Mcquaid, Christopher D. (2023): Epibiotic association of encrusting cheilostome bryozoans on shells of an invasive mussel from rocky shores of South Africa, with the description of a new aviculiferous species of Chaperia. Zootaxa 5258 (2): 197-210, DOI: 10.11646/zootaxa.5258.2.2, URL: http://dx.doi.org/10.11646/zootaxa.5258.2.2
0637D005154D0B4DFF387601E625FE11.taxon	discussion	Remarks. Celleporella hyalina has been reported to be widely distributed throughout the northern and southern hemispheres (e. g. Hincks 1880; Morris 1980; Moyano 1986). In South Africa, C. hyalina has been reported from Saldanha Bay on the west coast to Durban on the east coast (O’Donoghue 1924, 1957; O’Donoghue & de Watteville 1937, 1944; Florence et al. 2007). This species can typically be identified by its elongated, transversely striated frontal wall, often with a lunate umbo below the orifice, orifice of the female zooid wide and short, bearing a porous globular ovicell (Florence et al. 2007). The orifice shape of non-ovicelled zooids shown by Florence et al. (2007, p. 28, fig. 10 E, F) differs from the present material in having a deep U-shaped sinus as opposed to a broad shallow sinus (as seen in Fig. 3 B). These differences may reflect inter-lineage or interspecific variation. Morris (1980) also described variation in orifice shape for C. hyalina from the Pacific Coast of North America. Previous reports of C. hyalina from South Africa lack morphological measurements useful to quantify intraspecific variation of South African populations. Therefore, re-examining specimens from previous collections would be necessary for this purpose. In the present material, ovicelled zooids (N T = 5; mean length 0.28 mm by mean width 0.18 mm, Table 4) are smaller than non-ovicelled zooids (N T = 20; mean length 0.42 mm by mean width 0.22 mm, Table 4). The ovicells are prominent, globose and irregular in shape, with 5 – 11 conspicuous pores (N T = 10; mean number of pores = 8 ± 1) distributed over the entire surface as seen in colony SAMC-A 094526. Some studies have shown that C. hyalina can be considered as a species complex comprising significant morphological variation (e. g. Morris 1980; Navarrete et al. 2005; Grischenko et al. 2007). Integrated morphological, molecular, and reproductive-compatibility studies are required to better understand the C. hyalina species complex (Dick et al. 2005) and to establish species- and population-level diversity within this species complex in South Africa. Celleporella hyalina forms encrusting patches on mussels (this study), the fronds of kelp, and sometimes pelagic plastic debris in shallow waters (<30 m) from Saldanha Bay on the west coast to Durban on the east coast (Florence et al. 2007).	en	Boonzaaier-Davids, Melissa K., Ma, Kevin C. K., Mcquaid, Christopher D. (2023): Epibiotic association of encrusting cheilostome bryozoans on shells of an invasive mussel from rocky shores of South Africa, with the description of a new aviculiferous species of Chaperia. Zootaxa 5258 (2): 197-210, DOI: 10.11646/zootaxa.5258.2.2, URL: http://dx.doi.org/10.11646/zootaxa.5258.2.2
