Review and phylogeny of the New Zealand hagfishes (Myxiniformes: Myxinidae), with a description of three new species

Abstract

Hagfishes from New Zealand are reviewed and a phylogeny proposed using morphological and genetic data (DNA sequences of cytochrome c oxidase subunit I gene, COI, and the small subunit RNA, 16S). Eptatretus cryptus sp. nov. was previously confused with Eptatretus cirrhatus (Forster in Bloch & Schneider, 1801) because of their similar morphology, and is found from the Three Kings Islands to Stewart Island and in the eastern part of the Chatham Rise (at depths of 96–922 m). Eptatretus poicilus sp. nov. is endemic to the Three Kings Islands, where it is common and associated with soft sediment and deep‐sea coral‐sponge habitats (114–842 m). Neomyxine caesiovitta sp. nov. is a slender hagfish found along the east coast of the North Island south to the Chatham Rise (430–1083 m). A neotype is erected for E. cirrhatus (type locality: Breaksea Sound, Fiordland), occurring widely in New Zealand coastal, shelf, and slope waters (1–922 m), but not at the Three Kings Islands. Eptatetrus goliath Mincarone & Stewart, 2006, Neomyxine biniplicata (Richardson & Jowett, 1951), and Nemamyxine elongata Richardson, 1958 are further described using additional material. Rubicundus eos (Fernholm, 1991) is still only known from the holotype (type locality: Challenger Plateau). Genetic results showed that the New Zealand Eptatretus species form a monophyletic group within the subfamily Eptatretinae, indicating likely speciation from a single common ancestor within the area. Eptatretus poicilus sp. nov. is the sister species of E. cirrhatus, and E. cryptus sp. nov. is closely associated with the clade formed by these two species. Eptatretus goliath is most closely associated with Eptatretus minor Fernholm & Hubbs, 1981 (Gulf of Mexico), these two species basally diverging within New Zealand hagfishes. The endemic genus Neomyxine forms a well‐supported monophyletic group of as yet uncertain position within the phylogenetic tree. A key to the New Zealand hagfishes, fresh colour photographs, distribution maps, and in situ video recordings are presented. © 2015 The Linnean Society of London

Morphological analysis of the hagfish heart. II. The venous pole and the pericardium

“…A recent study (Zintzen et al, ) appears to indicate that E. cirrhatus is indeed a complex of two species , E. cirrhatus and E. cryptus . However, morphological differences are minimal, that is, small variations in the number of prebranchial slime pores and body color, and a clear distinction is only recognized by molecular techniques.…”

A critical appraisal of appendage disparity and homology in fishes

“…Myxines, or hagfishes, are either the most basal of extant craniates or they are basal vertebrates (see next subsection for hypothesized interrelationships among hagfishes, lampreys and gnathostomes) and comprise a single order, with about 79 extant species (Zintzen et al, 2015). (Bardack, 1991(Bardack, , 1998.…”

“…Myxiniformes although both species of Neomyxine present lateral folds of skin located immediately above the gill openings (Richardson, 1953(Richardson, , 1958Zintzen et al, 2015). Contrary to the paired fins found in most other craniates, these 'ventrolateral branchial fin-folds' are located dorsally to the branchial openings and do not seem to be used in swimming but rather as support when individuals settle on substrate (Adam & Strahan, 1963;Janvier, 1978;Richardson, 1953).…”

An integrated pathway for building regional phylogenies for ecological studies

“…The taxonomy and phylogenetic relationships of New Zealand's fishes is an area of active research and has included the discovery of several cryptic taxa in recent years (Delrieu-Trottin et al, 2018;Zintzen et al, 2015). Thus, our case study highlights the use of a spatially informed phylogeny constrained according to well-developed global phylogenies for fishes, and accordingly provides an excellent exemplar for the functionality of regPhylo.…”

“…Although New Zealand waters possess less than 10% of the overall diversity of marine ray‐finned fishes (1,106 recognized species; Roberts, Stewart, Struthers, Barker, & Kortet, ), they span a large diversity of clades, with many species (> 60%) also occurring elsewhere (Roberts et al ). The taxonomy and phylogenetic relationships of New Zealand's fishes is an area of active research and has included the discovery of several cryptic taxa in recent years (Delrieu‐Trottin et al, ; Zintzen et al, ). Thus, our case study highlights the use of a spatially informed phylogeny constrained according to well‐developed global phylogenies for fishes, and accordingly provides an excellent exemplar for the functionality of regPhylo .…”