Bradleytriebella tuberculata ( Hartmann, 1964 ), 2014Strandesia tuberculata Hartmann, 1964

Smith, Robin James, Lee, Jimin & Chang, Cheon Young, 2014, Nonmarine Ostracoda (Crustacea) from Jeju Island, South Korea, including descriptions of two new species, Journal of Natural History 49 (1), pp. 37-76 : 59-60

Genus Bradleytriebella Savatenalinton and Martens, 2009a Bradleytriebella tuberculata ( Hartmann, 1964)

( Figure 2G–J )

Strandesia tuberculata Hartmann, 1964

Strandesia decorata ( Sars, 1903) – Okubo 1990b, 2004. Synonymy herein.

Bradleystrandesia tuberculata ( Hartmann, 1964) nov. comb. Savatenalinton and Martens 2009b

Bradleytriebella tuberculata ( Hartmann, 1964) nov. comb. Savatenalinton and Martens 2009a

Remarks

The Korean specimens closely match the redescription provided by Savatenalinton and Martens (2009a), with the exception that the two small sub-marginal tubercles at approximately mid-height on the anterior part of the carapace (one on each valve) are very weakly developed or absent in the Korean material. In one specimen, there are very small tubercles on the carapace seen in dorsal view (marked with triangles on Figure 2H ), which correspond to the areas where tubercules are present in specimens from other areas. Within the superfamily Cypridoidea , some species have ornamentation present in some specimens while it is lacking in others. For example, Ilyocypris gibba ( Ramdohr, 1808) , Ilyocypris decipiens Masi, 1905 , Prioncypris zenkeri (Chyzer and Toth in Chyzer, 1858) , Heterocypris incongruens ( Ramdohr, 1808) , and Heterocypris salina ( Brady, 1868) typically have tubercles or denticles on the carapace, but such ornamentation can be lacking in some specimens/populations ( Meisch 2000). In the superfamily Cytheroidea , the presence or absence of tubercles of Cyprideis torosa is ecophenotypically induced (e.g. Keyser 2005), although it is not known what causes differences in surface ornamentation in the Cypridoidea . As the appendages and other carapace features of the Korean specimens are identical to the redescription of B. tuberculata from Thailand, we conclude that the Korean specimens represent a form of B. tuberculata with very weakly developed or absent tubercules.

In Japan, both Strandesia tuberculata and Strandesia decorata ( Sars, 1903) have been reported ( Okubo 1990b), but later the Japanese specimens were considered to all be S. decorata ( Okubo, 2004) . However, S. decorata has a smooth carapace ( Sars 1903; Savatenalinton and Martens 2010), whereas the Japanese specimens are clearly striated. We consider that the Japanese and Korean specimens are conspecific, and specimens with weak or no tubercles attributed to S. decorata by Okubo (1990b, 2000, 2004) are B. tuberculata . The Thai specimens figured by Savatenalinton and Martens (2009a) also appear to have two weakly developed posterior tubercules in addition to the two anterior tubercles, similar to Strandesia spinulosa Bronshtein in Akatova, 1958 . Further investigation is required to determine whether these two species are synonyms.

Bradleytriebella tuberculata is known from India ( Hartmann 1964 as S. tuberculata ), Thailand ( Savatenalinton and Martens 2009a), Japan ( Okubo 1990b as S. tuberculata and S. decorata ; Okubo 2000 as S. tuberculata and S. decorata ; Okubo 2004 as S. decorata ), and Taiwan ( Yu et al. 2009, as Bradleystrandesia tuberculata , citing grey literature). From Japan and Thailand it is known from rice fields, whereas the Korean specimens were recovered from a streamside seep (locality 17) and an irrigation pond (locality 26).

Figures

Figure 2. (A, B) Candona quasiakaina: (A) right view of male carapace (DB40033); (B) dorsal view of male carapace, anterior to right (DB40033). (C–F) Cyclocypris anacola n. sp.: (C) left view of female carapace (paratype, DB40035); (D) dorsal view of female carapace, anterior to right (paratype, DB40035); (E) internal view of female left valve (allotype, NIBRIV0000297034); (F) internal view of right valve (allotype, NIBRIV0000297034). (G–J) Bradleytriebella tuberculata: (G) left view of female carapace (DB40036); (H) dorsal view of female carapace, anterior to right (white triangles mark the areas where tubercles are weakly expressed) (DB40036); (I) internal view of female left valve (DB40037); (J) internal view of female right valve (DB40037). Scale bar = 587 µm for A, B; 209 µm for C–E; 269 µm for G–J.