Friday, June 10, 2016

[Ichthyology • 2016] Varicus lacerta • A New Species of Goby (Gobiidae, Gobiosomatini, Nes Subgroup) from A Mesophotic Reef in the southern Caribbean


Varicus lacerta
 Tornabene, Robertson & Baldwin, 2016

Figure 2. Holotype, USNM 434796, 36.2 mm SL, male, live. Photo by Barry Brown.
Figure 3.  Holotype, USNM 434796, prior to preservation. 

Abstract
We describe a new species of gobyVaricus lacerta sp. n., which was collected from a mesophotic reef at Curacao, southern Caribbean. The new species is the tenth species of Varicus, all of which occur below traditional SCUBA depths in the wider Caribbean area. Its placement in the genus Varicus is supported by a molecular phylogenetic analysis of three nuclear genes and the mitochondrial gene cytochrome b. In addition, the new species has one anal-fin pterygiophore inserted anterior to the first haemal spine, which distinguishes Varicus species from most species in the closely related and morphologically similar genus Psilotris. Varicus lacerta sp. n. is distinguished from all other named species of Varicus by the absence of scales, having highly branched, feather-like pelvic-fin rays, and in its live coloration. We provide the cytochrome c oxidase I DNA barcode of the holotype and compare color patterns of all species of Varicus and Psilotris for which color photographs or illustrations are available. This study is one of several recent studies demonstrating the utility of manned submersibles in exploring the diversity of poorly studied but species-rich deep-reef habitats.

Keywords: Systematics, molecular phylogeny, deep reefs, submersible, Curaçao, Psilotris


Figure 2. Varicus lacerta sp. n., holotype, USNM 434796, 36.2 mm SL, male, live. Photo by Barry Brown.


Diagnosis: Second dorsal fin I,9; anal fin I,7; pectoral fin 18; no scales; cephalic papillae rows 5s and 5i connected, forming a single row; pelvic rays 1-4 highly branched and feather-like; one anal-fin pterygiophore inserted anterior to first haemal spine; body with five broad, indistinct, dark vertical bands washed with bright yellow in life; pelvic, pectoral and anal fins yellow-orange in life, dorsal, anal, and caudal fins yellow with faint orange tint.

Habitat: The only known specimen was collected at 129–143 m. Quinaldine was dispersed around a yellow sponge (~20 cm tall) tentatively identified from videos by Allen Collins (National Marine Fisheries Service) as Dactylocalyx pumiceus, situated on a rocky outcropping along the deep-reef slope. After approximately 20 seconds the stunned fish emerged from a space in the rocky substrate at the base of the sponge and was captured. It is unclear whether the fish was originally in direct association with the sponge itself or was instead sheltering in spaces within the rock. Video of the capture taken from a high-definition video camera mounted on the outside of the Curasub is available online (youtu.be/UvxJEi-vER0). Subsequent collections targeting similar sponges and rocky substrates within this depth range at the type locality have not yielded additional specimens.

Distribution: Known only from the type location in Curaçao.

Etymology: The specific epithet ‘lacerta’ (Latin for ‘lizard’) is in reference to the reptilian or saurian appearance of this species, as indicated by its bright yellow and orange coloration, green eyes, disproportionately large head possessing raised ridges of papilla, and multiple rows of recurved canine teeth in each jaw. The common name Godzilla goby (gobio Godzilla in Spanish) refers to the radioactive reptilian monster from the sea that appeared in Japanese science-fiction films as Gojira, renamed Godzilla in subsequent English-language films.

Figure 6. Coloration of species of Varicus.
All illustrations by R. Grant Gilmore. Photographs by Barry Brown, Ross Robertson and Carole Baldwin (Varicus sp. 1), and the crew of the R/V Bellows (for V. vespa). Photos of V. bucca and V. benthonis not available.

 Luke Tornabene, D. Ross Robertson and Carole C. Baldwin. 2016. Varicus lacerta, A New Species of Goby (Teleostei, Gobiidae, Gobiosomatini, Nes Subgroup) from A Mesophotic Reef in the southern Caribbean. ZooKeys. 596: 143-156. DOI:  10.3897/zookeys.596.8217


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