Thalamoporella californica ( Levinsen, 1909 )

Chae, Hyun Sook, Yang, Ho Jin, Min, Bum Sik, Noh, Geon Woo & Seo, Dong Hee Lee and Ji Eun, 2022, Three newly recorded species of Korean fouling bryozoans, Journal of Species Research 11 (3), pp. 180-187 : 181-183

1. Thalamoporella californica ( Levinsen, 1909)

( Fig. 1 )

? Steganoporella rozieri form gothica Hincks, 1880: 380 .

Thalamoporella rozieri Robertson, 1908: 277 .

Thalamoporella rozieri var. E. ( californica ), Levinsen, 1909: 184.

Thalamoporella californica Hastings, 1930: 716 ; Osburn, 1950: 111; Soule, 1959: 33; Chaney, Soule and Soule, 1989: 345; Soule, Soule and Chaney, 1999: 21.

Not Thalamoporella californica : Long and Rucker, 1969: 62.

Material examined. Korea: Gyeongsangnam-do: Tongyeong yacht marina, 29 July 2020 ; MABIK IV00172 393 - MABIK IV00172395 , 7 July 2021 .

Substratum. Ropes.

Description. Colony light beige in color when alive, erect, dichotomously branching ( Fig. 1A, B ). Zooids distinct, rectangular, 0.39-0.57 mm long (0.47± 0.04 mm), 0.22-0.33 mm wide (0.25± 0.02 mm). Orifice sub- circular, 0.12-0.18 mm long (0.14± 0.01 mm), 0.12-

0.16 mm wide (0.14± 0.01 mm), approximately longer than wide, articulations tiny, arcuate distally with wide, shallow, concave sinus proximally; a pair of large and conspicuous adoral tubercles present or absent lateral to orifice ( Fig. 1C ). Cryptocyst flat, densely granulated, uniformly perforated, with two different sized opesiules. Avicularium nearly as long as autozooid, 0.44-0.49 mm long (0.46± 0.02 mm), acute triangular, tapering to rounded point, with smooth distal platform, vicarious or interzooidal, directed to distal: interzooidal avicularium situated at bifurcation of zooidal row; rostrum raised with slightly biconcave rim, length 65-70% of avicularium length; mandibular pivots developed, conspicuous; mandible tapering to rounded like round triangle, with smooth surface; opesia large, quadrated, gently concave proximal margin; cryptocyst, imperforate, smooth ( Fig. 1D ). Spicules only C-shaped calipers, no straight compasses ( Fig. 1E ). Ovicells very large, distinctive, hyperstomial, comprising two halves with median groove as typically thalamoporellid, 0.04-0.44 mm wide (0.43± 0.02 mm) ( Fig. 1F ).

Distribution. Korea, East Pacific (Monterey Bay to southern California, Colombia, and Galapagos Islands).

Remarks. Two species of the genus Thalamoporella , T. lioticha and T. sibogae , have previously been report- ed from Korea ( Rho and Seo, 1984: 1990; Seo, 1992: 1998 a; 1998b; 2005; 2010; Chae et al., 2016). In this study, we add Thalamoporella californica to the Korean bryozoan fauna. Both T. lioticha and T. sibogae encrust on substrates, and have two spicules (calipers and compasses); on the contrary, T. californica is cellariform with chitinous joints and has a number of only C-shaped calipers without a compass. In addition, avicularium is spatula shaped in T. lioticha and T. sibogae , whereas T. californica has a round triangular avicularium.

Thalamoporella californica is similar to T. arabiensis Amui and Kaselowsky, 2006 from Gulf of Aden in having features such as an erect, typically thalamoporellid ovicell and only C-shaped calipers without compass spicules. However, T. arabiensis is different from T. californica in having no tubercles and avicularia ( Amui and Kaselowsky, 2006). Thalamoporella prominens ( Levinsen, 1909) also resembles T. californica in that it has cellariform colonies with joints and no adoral tubercles, but smaller and larger ones are present in older zooids (i.e., absent or present adoral tubercles); however, T. prominens differs in having both calipers and compasses ( Soule et al., 1999). Table 2 provides a comparison of characteristics and distribution among the five Thalamoporella species mentioned above: T. arabiensis , T. californica , T. lioticha , T. prominens , and T. sibogae . In regard to distribution, T. arabiensis was recorded from the Indian Ocean and T. prominens from the Torres Strait. The three Thalamoporella found from Korea, T. californica , T. lioticha , and T. sibogae , were from the Pacific Ocean.

Long and Rucker (1969) reported T. californica from

Japan. However, spatulate avicularia of their Japanese specimen are clearly different from those of T. californica , which are triangular in shape with a round tip, described by Soule (1959), Chaney et al. (1989), and Soule et al. (1999).

Figures

Fig. 1. Thalamoporella californica (Levinsen, 1909). A, Colony; B, Dichotomous branch; C, Adoral tubercles of orifice and zooidal arrangement; D, Avicularium; E, C-shaped calipers; F, Ovicells. Scale bars: B=10mm; C, F=0.5 mm; D =0.2 mm; E=0.05mm.