A new genus and two new species of cavernicolous amphipods (Crustacea: Typhlogammaridae) from the Western Caucasus

This study deals with the biodiversity and distribution of cavernicolous Amphipoda in caves of the Arabika massif (Western Caucasus). The Sarma, Trojka and Orlinoe Gnezdo caves were explored during speleological expeditions over the years 2011–12. Two new species of Amphipoda were found: a sub-surface dweller Zenkevitchia sandroruffoi sp. nov. is reported from the Sarma, Trojka and Orlinoe Gnezdo caves at depths from -30 m to -350 m; the second one, a deep dweller Adaugammarus pilosus gen. et sp. nov. is reported from the Sarma Cave at depths of -1270 to -1700 m. Adaugammarus gen. nov. shares similarities with Typhlogammarus Schäferna, 1907 and Zenkevitchia Birstein, 1940. The species Anopogammarus birsteini Derzhavin, 1945 is also re-described herein based on new samples that suggest close affinity of this species with the family Gammaridae. The original taxonomic combination is resurrected for Zenkevitchia revazi Birstein &amp; Ljovuschkin, 1970, comb. resurr. (from Anopogammarus Derzhavin, 1945). To accommodate morphologically different species in the genus Zenkevitchia, two new groups are proposed. These are the admirabilis-group (Z. admirabilis Birstein, 1940 and Z. yakovi Sidorov, 2015) and the sandroruffoi-group (Z. sandroruffoi sp. nov. and Z. revazi). An updated molecular (mt-cox1) phylogeny, an identification key to the genera and a distribution map for the typhlogammarid amphipod species of Transcaucasia are provided.This study deals with the biodiversity and distribution of cavernicolous Amphipoda in caves of the Arabika massif (Western Caucasus). The Sarma, Trojka and Orlinoe Gnezdo caves were explored during speleological expeditions over the years 2011–12. Two new species of Amphipoda were found: a sub-surface dweller Zenkevitchia sandroruffoi sp. nov. is reported from the Sarma, Trojka and Orlinoe Gnezdo caves at depths from -30 m to -350 m; the second one, a deep dweller Adaugammarus pilosus gen. et sp. nov. is reported from the Sarma Cave at depths of -1270 to -1700 m. Adaugammarus gen. nov. shares similarities with Typhlogammarus Schäferna, 1907 and Zenkevitchia Birstein, 1940. The species Anopogammarus birsteini Derzhavin, 1945 is also re-described herein based on new samples that suggest close affinity of this species with the family Gammaridae. The original taxonomic combination is resurrected for Zenkevitchia revazi Birstein &amp; Ljovuschkin, 1970, comb. resurr. (from Anopogammarus Derzhavin, 1945). To accommodate morphologically different species in the genus Zenkevitchia, two new groups are proposed. These are the admirabilis-group (Z. admirabilis Birstein, 1940 and Z. yakovi Sidorov, 2015) and the sandroruffoi-group (Z. sandroruffoi sp. nov. and Z. revazi). An updated molecular (mt-cox1) phylogeny, an identification key to the genera and a distribution map for the typhlogammarid amphipod species of Transcaucasia are provided.</p

A new genus and two new species of cavernicolous amphipods (Crustacea: Typhlogammaridae) from the Western Caucasus

This study deals with the biodiversity and distribution of cavernicolous Amphipoda in caves of the Arabika massif (Western Caucasus). The Sarma, Trojka and Orlinoe Gnezdo caves were explored during speleological expeditions over the years 2011–12. Two new species of Amphipoda were found: a sub-surface dweller Zenkevitchia sandroruffoi sp. nov. is reported from the Sarma, Trojka and Orlinoe Gnezdo caves at depths from -30 m to -350 m; the second one, a deep dweller Adaugammarus pilosus gen. et sp. nov. is reported from the Sarma Cave at depths of -1270 to -1700 m. Adaugammarus gen. nov. shares similarities with Typhlogammarus Schäferna, 1907 and Zenkevitchia Birstein, 1940. The species Anopogammarus birsteini Derzhavin, 1945 is also re-described herein based on new samples that suggest close affinity of this species with the family Gammaridae. The original taxonomic combination is resurrected for Zenkevitchia revazi Birstein & Ljovuschkin, 1970, comb. resurr. (from Anopogammarus Derzhavin, 1945). To accommodate morphologically different species in the genus Zenkevitchia, two new groups are proposed. These are the admirabilis-group (Z. admirabilis Birstein, 1940 and Z. yakovi Sidorov, 2015) and the sandroruffoi-group (Z. sandroruffoi sp. nov. and Z. revazi). An updated molecular (mt-cox1) phylogeny, an identification key to the genera and a distribution map for the typhlogammarid amphipod species of Transcaucasia are provided

Variation of sperm morphology in Pacific oyster precludes its use as a species marker but enables intraspecific geo-authentification and aquatic monitoring

Abstract According to recent reports, shell morphology is unreliable for the identification of oysters because of the high phenotypic plasticity of these bivalves. Using COI DNA barcoding and sperm morphology, we reinvestigated the species validity of wild Pacific oyster Crassostrea gigas habituating the Peter the Great Bay (Sea of Japan). DNA barcoding confirmed the species validity of samples collected. Application of the single sperm pattern was not possible for species identification due to pronounced sperm plasticity being found. Six sperm morphs were discovered in the testes of each oyster collected. The amount of abundant sperm morphs and the type of the most dominant sperm pattern are particular to geographical localities that are individual depending on the environmental factors. Ecological monitoring of marine areas and commercially assigned intraspecific geo-authentification of the Pacific oyster seems possible based on the analysis of this species’ heterogenic sperm. Further work will be needed to test if sperm heterogeneity exists in other Ostreidae species and if heterogenic sperms could be used for interspecific analysis