More new deep-reef basslets (Teleostei, Grammatidae, Lipogramma), with updates on the eco-evolutionary relationships within the genus

Abstract

Two new Lipogramma basslets are described, L. barrettorum and L. schrieri, captured during submersible diving to 300 m depth off Curaçao, southern Caribbean. Superficially resembling L. robinsi in having 11–12 bars of pigment on the trunk, L. barrettorum is distinct from L. robinsi in having a stripe of blue-white pigment along the dorsal midline of the head (vs. a cap of yellow pigment), in patterns of pigment on the median fins, and in having 8–10 gill rakers on the lower limb of the first arch (vs. 11–12). Lipogramma schrieri is distinct from all congeners in having seven or eight dark bars of pigment on the trunk and broad, irregular, whitish blue markings on the dorsal portion of the head. The new species are genetically distinct from one another and from seven other Lipogramma species for which genetic data are available. A phylogenetic hypothesis derived from mitochondrial and nuclear genes suggests that the new species belong to a clade that also comprises L. evides and L. haberi. Collectively those four species are the deepest-living members of the genus, occurring at depths predominantly below 140 m. This study thus provides further evidence of eco-evolutionary correlations between depth and phylogeny in Caribbean reef fishes. Tropical deep reefs are globally underexplored ecosystems, and further investigation of Caribbean deep reefs undoubtedly will provide samples of species for which no genetic material currently exists and reveal more cryptic species diversity in the genus.

Plectranthias ahiahiata, a new species of perchlet from a mesophotic ecosystem at Rapa Nui (Easter Island) (Teleostei, Serranidae, Anthiadinae)

“…Scientists’ use of closed-circuit, mixed-gas rebreathers is allowing exploration and comparison between mesophotic and shallow coral ecosystems. The many new species descriptions resulting from the exploration of mesophotic reefs reveal the importance and uniqueness of these ecosystems (Pyle et al 2016; Baldwin et al 2016, 2018; Rocha et al 2017).…”