Fish biodiversity and conservation in South America.

The freshwater and marine fish faunas of South America are the most diverse on Earth, with current species richness estimates standing above 9100 species. In addition, over the last decade at least 100 species were described every year. There are currently about 5160 freshwater fish species, and the estimate for the freshwater fish fauna alone points to a final diversity between 8000 and 9000 species. South America also has c. 4000 species of marine fishes. The mega-diverse fish faunas of South America evolved over a period of >100 million years, with most lineages tracing origins to Gondwana and the adjacent Tethys Sea. This high diversity was in part maintained by escaping the mass extinctions and biotic turnovers associated with Cenozoic climate cooling, the formation of boreal and temperate zones at high latitudes and aridification in many places at equatorial latitudes. The fresh waters of the continent are divided into 13 basin complexes, large basins consolidated as a single unit plus historically connected adjacent coastal drainages, and smaller coastal basins grouped together on the basis of biogeographic criteria. Species diversity, endemism, noteworthy groups and state of knowledge of each basin complex are described. Marine habitats around South America, both coastal and oceanic, are also described in terms of fish diversity, endemism and state of knowledge. Because of extensive land use changes, hydroelectric damming, water divergence for irrigation, urbanization, sedimentation and overfishing 4-10% of all fish species in South America face some degree of extinction risk, mainly due to habitat loss and degradation. These figures suggest that the conservation status of South American freshwater fish faunas is better than in most other regions of the world, but the marine fishes are as threatened as elsewhere. Conserving the remarkable aquatic habitats and fishes of South America is a growing challenge in face of the rapid anthropogenic changes of the 21st century, and deserves attention from conservationists and policy makers.

Deep-sea bigscales, pricklefishes, gibberfishes and whalefishes (Teleostei: Stephanoberycoidei) off Brazil: new records, range extensions for the south-western Atlantic Ocean and remarks on the taxonomy of Poromitra.

The Stephanoberycoidei includes 23 genera and c. 94 species of deep-sea teleosts commonly known as bigscales, pricklefishes, gibberfishes and whalefishes. Stephanoberycoidei is one of the least known groups of deep-sea fishes, in spite of their apparent relative abundance in meso and bathypelagic depths. Nine species of the Stephanoberycoidei are reported here for the first time in Brazilian waters, and most of them represent new range extensions for the south-western Atlantic Ocean. Those species are Melamphaes polylepis, Melamphaes typhlops, Poromitra sp. and Scopeloberyx robustus (Melamphaidae), Acanthochaenus luetkenii and Stephanoberyx monae (Stephanoberycidae), Rondeletia bicolor and Rondeletia loricata (Rondeletiidae) and Gyrinomimus sp. (Cetomimidae). Occurrences of the pricklefish Scopelogadus mizolepis (Melamphaidae), the gibberfish Gibberichthys pumilus (Gibberichthyidae) and the velvet whalefish Barbourisia rufa (Barbourisiidae) are confirmed in the Brazilian exclusive economic zone, but previously published records of Poromitra capito and Melamphaes simus (Melamphaidae) in the region most likely represent misidentifications. Validities of the recently described Poromitra kukuevi and Poromitra indooceanica are discussed in light of new specimens of the genus collected in the south-western Atlantic Ocean. An identification key for the 13 species of Stephanoberycoidei reported off Brazil is also provided.

First record and further description of the Cape hagfish Myxine capensis(Myxinidae) off Mozambique, western Indian Ocean.

The first record of the Cape hagfish Myxine capensis in Mozambican waters is reported based on a single 356 mm total length specimen taken by bottom trawl off Maputo, 25° 52·9' S; 34° 42·7' E - 25° 54·1' S; 34° 41·0' E, at depths from 557 to 564 m. This account also represents the northernmost record of a hagfish in the western Indian Ocean. Morphometric and meristic data are provided and compared with those of 27 specimens (including the holotype) caught off Namibia and South Africa.

New records of coastal fishes in the northern Rio de Janeiro State, Brazil, with comments on the biogeography of the south-western Atlantic Ocean.

The distribution limits in the Atlantic of Callorhinchus callorynchus (Callorhinchidae) and Odontesthes argentinensis (Atherinopsidae) are extended northwards to 22° 22' S and 22° 31' S, respectively, whereas that of Lile piquitinga (Clupeidae) is extended southwards to 22° 22' S. Their occurrence in the north of Rio de Janeiro State is discussed. Remarks on the osteology of O. argentinensis, and morphometric and meristic data of L. piquitinga, are also provided.

Review of the Australian hagfishes with description of two new species of Eptatretus (Myxinidae).

This paper revises and updates taxonomic and distributional information about hagfishes (Myxinidae) from Australia. It covers five species of the genus Eptatretus: Eptatretus cirrhatus known from eastern Australia and also distributed around New Zealand, Eptatretus longipinnis endemic to South Australia, Eptatretus strahani originally described from the Philippines and reported here as a new record from Western Australia and two new species described herein as Eptatretus alastairi and Eptatretus gomoni, both from Western Australia. Eptatretus alastairi is distinguished from all congeners by the unique combination of the following characters: six pairs of gill pouches; three-cusp multicusps on the anterior and posterior rows of cusps; anterior unicusps 9-12; posterior unicusps 8-11; total cusps 48-56; prebranchial pores 13-16; branchial pores 5-6; trunk pores 50-55; tail pores 11-13; total pores 83-88; two bilaterally symmetrical nasal-sinus papillae in the dorsal surface of the nasal sinus. Eptatretus gomoni is distinguished from all congeners by the unique combination of the following characters: eight pairs of gill pouches; three-cusp multicusps on the anterior and two-cusp multicusps on the posterior row of cusps; anterior unicusps 10-11; posterior unicusps 9-10; total cusps 50; prebranchial pores 12-13; branchial pores 7-8; trunk pores 57-58; tail pores 14-15; total pores 91-93; no nasal-sinus papillae. An identification key for the Australian species of Eptatretus is also provided.

A new species of hagfish (Myxinidae: Eptatretus) from Papua New Guinea.

A new species of seven-gilled hagfish Eptatretus astrolabium (Myxinidae) is described from a 400 mm total length female trapped 1 km east from Planet Rock, Astrolabe Bay, Papua New Guinea, at c. 500 m depth. This is the first hagfish species reported from the waters around New Guinea. It can be distinguished from other hagfishes by a combination of characters including seven pairs of gill apertures, three-cusp multicusps on the anterior and posterior rows of cusps, 10 posterior unicusps, 52 total cusps, 18-19 prebranchial pores, five branchial pores, 48-49 trunk pores, 83-84 total pores and no nasal-sinus papillae.