Paracypridinae, Sars, 1923

Smith, Robin James & Chang, Cheon Young, 2022, Two new species of non-marine Ostracoda (Crustacea) of the genera Vestalenula Rossetti & Martens, 1998 (Darwinuloidea) and Microloxoconcha Hartmann, 1954 (Cytheroidea) from Tsushima, Japan, and a summary of the non-marine ostracod fauna of the island, Zootaxa 5150 (4), pp. 529-555 : 551

Paracypridinae

Of the three species of Paracypridinae found during our study ( Dolerocypria mukaishimensis Okubo, 1980 , Paracypria adnata Smith & Kamiya, 2006 and Paracypria inujimensis ( Okubo, 1980)) , all have a small protrusion on the antero-ventral calcified inner lamella of the left valve ( Fig. 8O, R & U ), a feature that has not been recorded in these species before. Within the tribe, the Thalassocypridini Hartmann & Puri, 1974 , some species of the genus Mungava Harding, 1962 have similar small protrusions on the left valve (the antero-ventral knob-like thickening of Wouters 1987), but it is absent in others ( Maddocks 2005). A similar protrusion also appears present in both Mangalocypria ryukyuensis Hiruta & Kakui, 2016 and Paracypria plumosa Hiruta & Kakui, 2016 (see SEM figures in Hiruta & Kakui 2016), but due to a lack of internal SEM photographs of the left valve for most Thalassocypridini species, it is not clear how widespread this feature is. A tooth on the antero-ventral calcified inner lamella of the left valve and a corresponding socket on the right valve were used by Wouters (2001) as a diagnostic feature of the tribe Renaudcypridini McKenzie, 1980 . There is no corresponding socket on the right valve in P. adnata , P. inujimensis and D. mukaishimensis , and it seems that instead the edge of the right valve clips into the gap between the protrusion and the edge of the left valve. However, the protrusion in these three species is probably homologous with the tooth of the Renaudcypridini . Although the protrusion/tooth/knob is present in at least some of the species in the tribe Thalassocypridini , a socket on the right valve may still be a diagnostic feature of the tribe Renaudcypridini .

Figures

FIGURE 8. A & B, Cryptocandona tsukagoshii. A, female, RV, ext. B, female, LV, int. C & D, Fabaeformiscandona subacuta. C, male, LV, ext. D, male, RV, int. E & F, Pseudocandona abei. E, female, LV, ext. F, female, LV, int. G & H, Schellencandona yakushimaensis. G, female, LV, ext. H, female RV, int. I & J, Physocypria nipponica. I, male, RV, ext. J, male, LV, int. K & L, Cypretta seurati. K, female, RV, ext. L, female, RV int. M–O, Dolerocypria mukaishimensis. M, male, RV, ext. N, male, LV, int., arrow indicates position of antero-ventral tooth. O, male, LV, int., detail of antero-ventral tooth. P–R, Paracypria adnata. P, male, RV, ext. Q, male, LV, int., arrow indicates position of antero-ventral tooth. R, male, LV, int., detail of antero-ventral tooth. S–U, Paracypria inujimensis. S, female, RV, ext. T, female, LV, int., arrow indicates position of antero-ventral tooth. U, female, LV, int., detail of antero-ventral tooth. Scale bar = 445 µm for A & B, 617 µm for C & D, 381 µm for E & F, 289 µm for G & H, 403 µm for I & J, 464 µm for K & L, 396 µm for M & N, 392 µm for P & Q, 473 µm for S & T, and 77 µm for O, R & U.