Primavelans glabricollaris, Min & Chae & Yang & Noh & Seo, 2021

Min, Bum Sik, Chae, Hyun Sook, Yang, Ho Jin, Noh, Geon Woo & Seo, Dong Hee Lee and Ji Eun, 2021, A new species and new record of Pacificincolidae (Bryozoa: Cheilostomata) from Korea, Journal of Species Research 10 (3), pp. 276-286 : 281-282

Primavelans glabricollaris n. sp. ( Fig. 3 )

Mucronella perforata : Rho and Seo, 1985, p. 4, pls. 9, 10. Pacificincola perforata Hirose, 2010 , pp. 124, 125, pl. 214

A- E. Not Pacificincola perforata ( Okada and Mawatari,

1937).

Type. Holotype: MABIK IV00170721 , One intact colony, collected by 21 Nov. 2009 at rocky shore of Munseom Island , Jeju-do, (B.S. Min and H.J. Yang) by SCUBA diving from 25-30 m in depth . Paratype: MABIK IV00170722 , Bangeojin Port, 13 Aug. 2009, by B.S. Min, and H.J. Yang .

Additional material examined. Yeondaedo Island , 10 Jul. 1964 ; Yeonhwado Island , 19 Jul. 1978 ; Seogwipo , 13 Jul. 1979 ; Sangju-ri , 20 May 1981 ; Mipo , 25 May 1981 ; 8 Dec. 1981 ; Dodong , 11 Jul. 1984 ; Neunggeol , 26 Aug. 2003 ; Deoksan Port , 7 Jul. 2002 ; Gyedo Island , 24 Jun. 2008 ; Yangpo Port , 12 Aug. 2009 ; 24 Jun. 2010 ; 24 Jun. 2011; 22 Aug. 2012; 22 Dec. 2012; 25 Feb. 2014; 3 Mar. 2015; Bangeojin Port , 13 Aug. 2009 ; Gujora Port , 15 Aug. 2009 ; Jumunjin Port , 30 Aug. 2009 ; Daebyeon Port , 19 Sep. 2009 ; Munseom Island , 6 Oct. 2009 (J.E. Seo, B.S. Min and H.J. Yang) by SCUBA diving from 30 m in depth; 21 Nov. 2009 ; 19 Jan. 2010 (B.S. Min and H.J. Yang) by SCUBA diving from 25-30 m in depth; Jodo Island , 5 May 2010 (B.S. Min and H.J. Yang) by SCUBA diving from 10 m in depth; Yokjido Island , 1 Nov. 2011 (B.S. Min and S.G. Ra) by SCUBA diving from 10-15 m in depth; 2 Nov. 2011 (B.S. Min and S.G. Ra) by SCU- BA diving from 10-15 m in depth; Ganggu Port , 17 Jan. 2012 ; Daegueulbido Island , 25 Jun. 2013 (B.S. Min) by SCUBA diving from 10-15 m in depth; Daetseom Island , 26 Jun. 2013 ; Tongyeong Port , 2 Mar. 2015 ; Gyeongpodae ( Gangneung-si ) 5 May 2015 (B.S. Min and J.K. Jung) by SCUBA diving from 15 m in depth; Gapado Island (Jeju-do) 5 Jul. 2015 (B.S. Min, H.J. Yang and J.K. Jung) by SCUBA diving from 25 m in depth; Almado , 20 Jul 2017 (B.S. Min) by SCUBA diving from 25 m in depth; Hongdo , 26 Apr. 2018 (B.S. Min) by SCUBA diving from 25 m in depth .

Substrata. Anthozoans (sea fans), hydrozoans, oyster shells, rocks, buoys (plastic or styrofoam).

Description. Colony unilaminar, encrusting when young; erect and massive, growing up into bilaminar to about 20 cm in diameter when older; light yellow, or orange when alive. Zooids elongate, rounded-hexagonal, or bar- rel-shaped, 0.45-0.84 mm long (average 0.62± 0.10 mm), 0.20-0.29 mm wide (average 0.26± 0.04 mm). Frontal wall slightly convex, evenly perforated, pustulose between perforations. Orifice subcircular, slightly wider than long, 0.14-0.21 mm long (average 0.18± 0.02 mm), 0.16-0.21 mm wide (average 0.19± 0.02 mm), with a wide, shallow sinus flanked by blunt condyles. Zooids of two types, male with a smaller orifice and female with a larger orifice. Male zooid, 0.49-0.5 mm long (average 00.48± 0.03 mm), 0.12-0.19 wide (average 0.16± 0.04 mm). Orifice of male zooid, 0.10-0.13 mm long (average 0.18± 0.01 mm), 0.09-0.11 wide (average 0.10± 0.01 mm). Peristome not well developed. Small heterozooid proximal to orifice forms lunate umbo small, elliptical foramen. Ovicell conspicuous, globose, reaching to condyles and leaving only 1/3 of orifice when mature, surface pustulose, 0.29-035 mm long (average 0.31± 0.02 mm), 0.25-0.29 mm wide (average 0.27± 0.01 mm); generally with a few tiny pores on surface. Developing ovicells with thin ribs radiating from proximal margin; mature ovicells lacking ribs but having a smooth zone along proximal margin and paired, thin, raised basal flanges at proximal corners, and appear to be closed by zooidal operculum ( Fig. 3C ). Spines and avicularia lacking. Ancestrula oval in outline, 0.11 mm long (average 0.11±0.00 mm), 0.10- 0.13 mm wide, (average 0.12±0.2 mm) budding a distal and two distolateral primary daughter zooids; frontal wall of ancestrula covered by the two lateral daughter zooids, having a median longitudinal ridge, only the ancestrular orifice remaining free.

Etymology. The species name is from the Latin glaber (smooth), collarium (collar), reflecting to the mature ovicell having with smooth collars.

Remarks. There are three species belonging to the genus Primavelans , Primavelans insculpa and Primavelans mexicana from the east Pacific, and Primavelans glabricollaris n. sp. The proximal lip by blunt and downcurved condyles of the orifice in our new species is more straight than slightly convex by sharp condyles in Primavelans insculpta . The condyles of Primavelans mexicana are much smaller than the rest two species of Primavelans , which it form the proximal lip arched slightly in the mid- dle ( Soule, Soule and Chaney, 1995). Both Primavelans glabricollaris n. sp. and Primavelans insculpta has two types of zooids, male with a smaller orifice and female with a larger orifice. However, the former species has more rare male zooids than the latter ( Nielsen, 1981). The ovicell in Primavelans glabricollaris n. sp. is minutely perforated and has thin flanges at the proximolateral corners and a smooth zone along the proximal margin, which seems to conform to the shape of the zooidal operculum. In addition, Primavelans glabricollaris n. sp. in lacking ridges on the mature ovicell differs from Primavelans insculpta , which has few small pores closed by advanced calcification ( Soule, Soule and Chaney, 1995). Primavelans mexicana has the imperforate ovicell with lateral oral flanges showing difference from the one of Primavelans glabricollaris n. sp. ( Soule, Soule and Chaney, 1995) ( Fig. 3 ). Japanese specimen from Sagami Bay ( Hirose, 2010) does not show the ancestrula of the genus Primavelans ; however it is clearly different from Pacificincola perforata in having perforate ovicell with thin flanges at its proximolateral corners and deeply covering zooidal orifice, when mature ( Hirose, 2010). Thus, of Japanese specimens, the one from Sagami Bay seems to be different from the one from Akkeshi Bay, Hokkaido.

Ecology. Primavelans glabricollaris n. sp. is initially unilaminar but then grows and rises into irregular, bilaminar and frilled massive colony in case of materials collected from a depth of about 25 m. This new species is a fouling bryozoan attached to the ropes hanging on wharfs or aquaculture cages. Most colonies collected from Jeju-do and eastern and southern shoreline of Korea are common- ly attached to buoys such as plastics or styrofoam in ports. In scallop farms, colonies of the new species encrust the aquaculture cages, and interrupt the growth of young scal- lops, causing a disturbance to the flow of water. This new species on hydroids seems to be found in Europe (personal communication). Occasionally in Jeju-do, other inverte- brates, such as decapods and starfish, are found within the colony of this species .

Figures

Fig. 3. Primavelans glabricollaris n. sp. (A) Hongdo, 26 Apr. 2018; (B-D) Jumunjin Port, 30 Aug. 2009. A, autozooids. arrow indicates male zooid; B, D-shaped orifice; C, ovicells with minute pores, paired proximilateral flanges, and smooth zone along proximal margin, which appears to conform shape of operculum; D, ancestrula with triplet of primary daughter zooids, with secondary calcification covering ancestrula proximal to orifice. Scale bars:A, C, D=0.10 mm, B=0.01 mm.