Schizoporella japonica Ortmann, 1890

Fig. 14 A–F

Schizoporella unicornsis var. japonica Ortmann, 1890: 49, pl. 3, fig. 35.

Schizoporella japonica – Ryland et al. 2014: 485, figs 2–5.

Material

MALAYSIA: MSL BRY019b, BRY024, Kuah jetty, Langkawi, encrusting bivalves fouling a rope hanging from the jetty.

Description

Colony encrusting, multiserial, unilamellar, growing edge locally developing giant buds (Fig. 14B); vivid yellow-orange when alive (Fig. 14A). Autozooids small, 0.48–0.60 mm long by 0.18–0.38 mm wide, elongate, on average 1.9 × longer than wide; frontal shield convex, with marginal areolar pores and abundant deep pseudopores, suboral umbo; orifice about as long as wide, 0.11–0.14 mm in both dimensions, sinus wide, shallow, broad condyles occupying outer two-thirds of hingeline on either side of sinus (Fig. 14D); ovicell prominent, porous (Fig. 14 E–F). Adventitious avicularia (Fig. 14D) present in about one-third of autozooids, typically lacking in narrower examples, never more than one per zooid, proximal end level with proximal edge of orifice, directed distolaterally, about 0.11 mm long by 0.06 mm wide; rostrum a high triangle with slightly concave edges and rounded distal end somewhat raised; cross-bar straight; opesia semicircular.

Remarks

Ryland et al. (2014) comprehensively redescribed Schizoporella japonica and provided information on its geographical distribution, focusing especially on its recent introduction into western Europe. Living colonies of S. japonica from Langkawi have a vibrant yellow-orange colour, similar to the specimen from Friday Harbor, Washington depicted by Ryland et al. (2014: fig. 2d), although some of the colonies described by these authors are redder in colour. The Langkawi material has rather smaller autozooids than is usual for this species, which may reflect the warm ambient seawater temperature, and the avicularia tend to be slightly more laterally orientated.