Monday, May 18, 2020

[Invertebrate • 2020] Vampyroctena delmarvensis (Vampyroctenidae, fam. nov.) • A Mesopelagic Ctenophore representing A New Family, with Notes on Family-level Taxonomy in Ctenophora


Vampyroctena delmarvensis Townsend, Damian-Serrano & Whelan

in Townsend, Tassia, Damian-Serrano, et al., 2020.

Abstract
The stunning diversity of midwater ctenophores is well-known to veterans of oceanographic cruises and ROV operations, but many species lack formal descriptions, leading to taxonomic confusion and a systematic underestimation of the biodiversity of the mesopelagic zone. Here, we present a description of a novel genus and species of one such ctenophore, Vampyroctena delmarvensis gen. nov. sp. nov. This cydippid ctenophore, the sole described representative of Vampyroctenidae fam. nov. (Class Tentaculata, Order Cydippida), was collected in mesopelagic waters off the coast of Delaware in the northwest Atlantic Ocean and has a characteristic bright red mesoglea, large paragastric diverticulae, deep red macrocilia, and a darkly pigmented gut. A molecular phylogenetic analysis of Ctenophora based on transcriptomic data places V. delmarvensis gen. nov. sp. nov. as the closest known relative to Euplokamis dunlapae Mills, 1987 (Euplokamididae), in a clade that is sister to all other ctenophore lineages.

Keywords: 18S, Atlantic Ocean, Delmarva, Molecular phylogeny, New species, Transcriptome, Tucker trawl

 Vampyroctena delmarvensis gen. nov. sp. nov. anatomy.
Schematic representation of V. delmarvensis gen. nov. sp. nov. anatomy based on accumulated photographs, video, and notes.

 Vampyroctena delmarvensis gen. nov. sp. nov. anatomy.
 b Representative photograph of V. delmarvensis gen. nov. sp. nov. in the stomodeal plane; c Close-up of aboral organ depression and surrounding meridional canals; d Close-up of comb rows, showing the underlying light orange meridional canal; e Close-up view of paragastric diverticulae; f Detail showing the tentacle sheaths, which open into a broad groove spanning ~ 30% of the animal’s total body length.

Systematics

Vampyroctenidae fam. nov. Townsend, Damian-Serrano & Whelan


Vampyroctena gen. nov. Townsend, Damian-Serrano & Whelan

Etymology: Compound feminine noun derived from the French “vampyre” and Greek κτεíςκτενóς, “comb.” This metaphorical comparison to mythological creatures refers to the dark gut pigmentation, which may serve as a “cloak” enabling them to hide bioluminescence emitted from captured prey, and the blood red pigmentation of the epithelium, comb plates, and mesoglea.

Diagnosis: Tentaculate ctenophores with bright red mesoglea and an elongate, cylindrical body. Adults with large, darkly pigmented stomodaeum. Comb rows with large, pigmented ctenes. Orange canals, tentacle bulbs, and tentacles which bear tentilla.


Vampyroctena delmarvensis sp. nov. Townsend, Damian-Serrano & Whelan

Etymology: Compound noun from “Delmarva,” the colloquial name for the peninsula nearest to the type locality, derived from the three states that occupy it: Delaware, Maryland, and Virginia.


 Vampyroctena delmarvensis gen. nov. sp. nov. anatomy.
 a Schematic representation of V. delmarvensis gen. nov. sp. nov. anatomy based on accumulated photographs, video, and notes; 
b Representative photograph of V. delmarvensis gen. nov. sp. nov. in the stomodeal plane; c Close-up of aboral organ depression and surrounding meridional canals; d Close-up of comb rows, showing the underlying light orange meridional canal; e Close-up view of paragastric diverticulae; f Detail showing the tentacle sheaths, which open into a broad groove spanning ~ 30% of the animal’s total body length.


James P. Townsend, Michael G. Tassia, Alejandro Damian-Serrano, Nathan V. Whelan, Kenneth M. Halanych and Alison M. Sweeney. 2020. A Mesopelagic Ctenophore representing A New Family, with Notes on Family-level Taxonomy in Ctenophora: Vampyroctena delmarvensis gen. nov. sp. nov. (Vampyroctenidae, fam. nov.). Marine Biodiversity. 50: 34.  DOI: 10.1007/s12526-020-01049-9