Date Awarded

1984

Document Type

Dissertation

Degree Name

Doctor of Philosophy (Ph.D.)

Department

Virginia Institute of Marine Science

Abstract

The eelpouts, Zoarcidae, are a group of bony fishes, most species of which inhabit continental shelves and slopes of boreal seas. There are about 200 species of eelpouts, most of which are rare in collections, thus they have been only cursorially studied by most workers. as a result, the systematics of the family is in a poor state. This work is a contribution to the improvement of that state. The anatomy of all nominal genera of Zoarcidae was studied in an attempt to reconstruct phylogeny and establish the limits of genera. From analysis of a matrix of 63 characters, the 43 nominal genera recognized here form two subfamilies. One, Lycozoarcinae, contains only the primitive Lycozoarces regani. The other, Zoarcinae, is divided into three tribes, Zoarcini, Gymnelini and Lycodini. The more primitive zoarcids are characterized by having 4-6 suborbital bones arranged in a circular pattern close to the orbit, and complete cephalic lateralis pore patterns, except some of the few deep-sea forms. The more derived zoarcids are characterized by the loss of the interorbital pore (except for a few reversals) and by having 6-11 suborbital bones arranged in an "L-shaped" pattern away from the orbit (except a few which have lost some bones). An hypothesis is presented for the sister group relationship of Zoarcidae with six zoarceoid families: Ptilichthyidae, Zaproridae, Anarhichantidae, Stichaeidae, Pholididae and Scytalinidae. Bathymasteridae is hypothesized to be the primitive sister group of all the above taxa. The zoarceoids are probably most closely related to notothenioids and some of the trachinoids than to blennioids, a group recently restricted to six tropical-subtropical families. Since fully 45% of the genera recognized here are known from less than 15 specimens each, zoogeographic patterns are unsatisfactorily resolved. Considering the known distributions of all zoarcid genera, the highest endemism is found in temperate South America (30%), the northwestern Pacific (23%) and northeastern Pacific (11%). The best known deep-sea genera and species are wide-ranging, this perhaps due to the benthic, precocious larvae of most species.

DOI

https://dx.doi.org/doi:10.25773/v5-qgxc-9x74

Rights

© The Author

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