Marcelo R. S. Melo

A New Synaphobranchid Eel (Anguilliformes: Synaphobranchidae) from Brazil, with Comments on the Species from the Western South Atlantic

Abstract A new synaphobranchid eel from the Brazilian continental slope is described herein as Synaphobranchus calvus. The species is distinguished from its congeners by the absence of scales on the head (vs. head scaled in other species) and its black to brown body with a deep blue belly (vs. body entirely black, gray, or brown in the remaining species). Further comments about the synaphobranchid eels of the western South Atlantic are given and a key with new characters to all species of Synaphobranchus are provided.

Revision of the Genus Chiasmodon (Acanthomorpha: Chiasmodontidae), with the Description of Two New Species

Abstract Chiasmodon is a genus of meso- and bathypelagic fishes, commonly known as swallowers. The genus has a wide distribution in the Atlantic, Pacific, Indian, and Southern Oceans. Five species previously described are considered valid and two are described as new: C. niger, from tropical North Atlantic, including the Gulf of Mexico and Caribbean; C. subniger from the eastern Pacific; C. braueri from the Indian, western and Central Pacific, and western South Atlantic; C. microcephalus, from southern parts of the Atlantic, Indian, and Pacific, and the Southern Ocean; C. pluriradiatus from tropical Atlantic, Indian, and Pacific; C. asper n. sp., from the temperate North Pacific; and C. harteli n. sp., from the temperate North Atlantic. Chiasmodon bolangeri is considered a junior synonym of C. niger, and C. lavenbergi a junior synonym of C. pluriradiatus. Taxonomic keys to the family Chiasmodontidae and to the species of Chiasmodon, as well as updated maps of distribution are provided.

Characidium stigmosum (Characiformes: Crenuchidae): A New Species of Characidiin Fish from Central Brazil

Abstract A new species of Characidium is described from tributaries of the rio Paranã (Tocantins drainage), in Goiás State, central Brazil. Characidium stigmosum is diagnosed by the presence of dark marks along the sides of the body, which are associated with the vertical bars that occur in most species of Characidium. These marks are vertically oriented elliptical, except one or two anteriormost marks which may be roundish or horizontally elongate; there is usually one mark for each bar above abdominal area and two marks for each bar on posterior half of body; lower marks are slightly offset posteriorly. Characidium stigmosum shares apomorphic traits with the clade comprised of Characidium rachovii, Characidium occidentale, Characidium orientale, and Characidium vestigipinne.

A New Species of Characidium Reinhardt (Characiformes, Crenuchidae) with a Distinctively Dimorphic Male

We herein describe Characidium satoi, new species, only known from its type locality at Rio Curral das Éguas, a small tributary of Rio Abaeté, in the Rio São Francisco basin, Brazil. It can be distinguished from its congeners by the following characteristics: area between the pelvic fin and the origin of anal fin moderate to strongly convex in lateral view; presence of irregular and discontinuous bars, forming dorsal blotches separated from ventral V-, W-, or diamond-shaped marks; and the first anal-fin radials inserted between the fifth and sixth caudal vertebrae. The juveniles and mature females of Characidium satoi, new species, have smooth fin rays, while mature males have hooks on pelvic and, in some specimens, pectoral and dorsal fins. Moreover, females and immature males have irregular bars on dorsum and fuzzy vertical bars on body; during the breeding season, males develop uniformly darker pigmentation on body and head, lacking any distinctive vertical bar on body. This seasonal color dimorphism is reported in the family Crenuchidae for the first time.

A new species of Characidium Reinhardt, 1867 (Characiformes: Crenuchidae) endemic to the Atlantic Forest in Paraná State, southern Brazil

A new species of Characidium is described based on specimens obtained from the highland streams of the Serra do Mar, Atlantic Forest Biome, in Parana State, Southern Brazil. The new species is possibly a member member of the C. lauroi group, which is diagnosed by having the isthmus unscaled, bars poorly marked, and spots on sides of body, and is composed by four additional species: C. japuhybense ; C. lauroi ; C. oiticicai ; and C. schubarti . The new species differs from its congeners with naked isthmus, except C. helmeri , by having 15-18 principal caudal-fin rays; and 10-12 pectoral-fin rays; and from C. helmeri , by having a slender body, tip of pectoral fin not reaching origin of pelvic fin, tip of pelvic fin not reaching beyond anus, supraorbital present and well developed, and by lacking vertically elongated dashes on sides of body. The new species is known from tributaries of the rio Jordao, in the rio Iguacu Basin, and rio Taquari, a tributary of the rio Ribeira de Iguape coastal drainage.

Redescription of Urophycis brasiliensis (Kaup 1858), a senior synonym of Urophycis latus Miranda Ribeiro 1903 (Gadiformes: Phycidae).

Urophycis Gill 1864 is a genus of demersal fish composed by eight valid species with anti-tropical distributions in the western Atlantic. Only two species occur in the South Atlantic: U. brasiliensis (Kaup 1858) and U. mystacea Miranda Ribeiro 1903. These species have similar ranges from southeastern Brazil to northern Argentina, but U. brasiliensis occurs in more shallow waters than U. mystacea. Both species are important fishery resources in southern Brazil and Uruguay. Herein, we redescribe U. brasiliensis based on comparison of types and additional specimens, including the description of the Sagitta otolith, formerly place U. latus Miranda Ribeiro 1903 as a junior synonym of U. brasiliensis, and provide an updated map of distribution.