A new species of chimaerid, Hydrolagus erithacus sp. nov., is described from nine specimens collected from the southeast Atlantic and southwest Indian oceans from depths of 470-1,000 meters. This species is distinguished from all other Hydrolagus species based on the following characteristics: head bulky, relatively large, followed by stocky body; head and body height from about pectoral fin origin to pelvic fin origin similar, then tapering rapidly to filamentous tail; first dorsal fin spine height about equal to, or slightly less than first dorsal fin apex height; second dorsal fin up to 81% of total body length and uniform in height; trifurcate claspers forked for approximately 20% of total length; robust frontal tenaculum nearly uniform in width, prepelvic tenaculae with five to seven medial spines, and a uniform black coloration with robust, non-deciduous skin. Comparison of mitochondrial NADH2 gene sequences with other morphologically similar Hydrolagus species suggests that H. erithacus is a distinct species.

Hydrolagus africanus (Gilchrist, 1922) is a little-known chimaeroid species, originally described from the KwaZulu-Natal coast of South Africa, with a range spanning the western Indian Ocean from Kenya, south to Mozambique and South Africa, and extending into the south-eastern Atlantic to Namibia. This species is characterised by a lateral patch of denticles on the male prepelvic tenacula, a second dorsal fin slightly indented in the centre, a long, curved dorsal spine equal to or sometimes exceeding the height of the first dorsal fin, and a uniform light brown body with no distinctive markings or patterns and slightly darker brown fins. To clarify the taxonomic status of H. africanus, we examined and compared specimens from throughout its range in southern Africa. Because the syntypes of H. africanus are lost, we designate a neotype and redescribe the species based on the neotype and additional southern African specimens. In addition, we present a review of southern African chimaeroids and provide an updated key to their identification.

No abstract

No abstract

TAXONOMIC REVISION OF THE SHORT NOSE CHIMAERAS (GENUS HYDROLAGUS) FROM THE SOUTHERN AFRICAN REGION by Kristin A. Walovich Short-nose chimaeras are an enigmatic and understudied group of deep-sea Chondrichthyan fishes. To resolve decades of confusion and misidentification in the southern African region, morphometric and genetic data were utilized to resolve taxonomic confusion for the genus Hydrolagus. Nearly 100 chimaeroid specimens were examined from numerous national and international museum ichthyology collections. A series of 96 measurements per specimen were recorded and analyzed with multivariate statistics to determine differences among species. Tissue was collected from various southern African species for analysis of the mitochondrial gene NADH2. The resulting genetic information was compared to morphologically similar species and those within the same geographical region. This study re-describes Hydrolagus africanus, officially describes a new species Hydrolagus erithacus sp. nov, identifies a species known as Hydrolagus cf. trolli as Hydrolagus affinis, and provides taxonomic clarification and detailed descriptions for all three species. The morphological and genetic differences between species of this genus are not pronounced, presenting challenges for identification and classification. Species clarification enables improved identification and fisheries statistics, informed management efforts, and the advancement of chimaera genetic and biological research. v Acknowledgements This thesis would not have been possible if not for the guidance and support from numerous people. Sincere thanks are owed to my three thesis advisors, Dr. David Ebert, whose immense knowledge of Chondrichthyans has helped save three more "Lost Sharks", Dr. Scott Hamilton, whose help extends back to my undergraduate days, and Dr. Kenneth Coale, for his unflagging support and insight. Thank you to Jenny Kemper (Medical University of South Carolina), whose work ethic, productivity and knowledge I strive to emulate. A special thanks goes to Rob Leslie (South African Department of Agriculture, Forestry and Fisheries) who has been instrumental to the success of my thesis. A number of people were very helpful during this research and I wish to extend a very appreciated thank you to Dominique Didier (Millersville University) and Douglas Long (Saint Mary's College) for their assistance on the Hydrolagus africanus paper, Gavin Naylor (College of Charleston, South Carolina), Mattias Lanas and Mark Dando who contributed their time and immense talent to draw the illustrations for my thesis, and to the staffs at the numerous museum collections and institutions I was privileged to visit