Volume 14, Issue 4, 15 October 2008
Volume 14, Issue 4 – 15 October 2008
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Aaron P. Jenkin, Gerald R. Allen and David Boseto: Lentipes solomonensis, a new species of freshwater goby (Teleostei: Gobioidei: Sicydiinae) from the Solomon Islands , pp. 165-174
A new species of freshwater gobiid, Lentipes solomonensis, is described on the basis of 10 specimens, 18.2-26.9 mm SL, collected from Rendova, Ranongga and Makira Islands, Solomon Islands. The species is distinguished from its closest relatives by a combination of characters that include: dorsal rays VI-I, 9; anal rays I, 9; pectoral rays usually 16; membrane of last spine of first dorsal fin connected to base of second dorsal fin origin in males; upper jaw with 12-16 tricuspid teeth in males; single pair of broad and flattened lobes obscuring most of a pointed urogenital papillae in males and absent in females; female urogenital papillae rectangular and usually retracted into sheath-like groove; male upper lip and snout golden yellow, diffusing posteriorly into golden-yellow flecks along dorsal half of trunk to caudal peduncle; basal two thirds of dorsal and pectoral fins golden-yellow, second dorsal fin with pearl white spot outlining a small dark spot medially at ray one.
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Lentipes kaeaa, Tarihau Creek, Makira Island, Western Province, Solomon Islands, in situ photo of live specimen, USPS 5794, male, 28.5 mm SL. Photo by G. R. Allen
Maria Anaïs Barbosa and Wilson J. E. M. Costa: Description of a new species of catfish from the upper rio Paraíba do Sul basin, south-eastern Brazil (Teleostei: Siluriformes: Trichomycteridae) and re-description of Trichomycterus itatiayae, pp. 175-186
Trichomycterus nigroauratus n. sp. is described from south-eastern Brazil and Trichomycterus itatiayae is redescribed. Trichomycterus nigroauratus differs from all the remaining species of Trichomycterus by possessing golden spots on its snout and body. The species seems to be closely related to T. itatiayae, based on the presence of a broad metapterygoid, which is wider than long, and colour pattern that exhibits a black stripe along the lateral midline, which posteriorly reaches the caudal fin posterior margin, at least in juveniles. Trichomycterus nigroauratus differs from T. itatiayae mainly by the number of rays on the pectoral fin, the related position of the anal fin, the morphology of the opercular and interopercular odontodes, the autopalatine and urohyal bones, the caudal fin and by its colour pattern. Trichomycterus diabolus also has a broad metapterygoid but seems to be closely related to T. castroi, with which it shares a distinctive unpigmented area on the basal region of the caudal fin. Trichomycterus nigroauratus and T. itatiayae are often found together living syntopically in small mountain rivers of the region, swimming close to the substrate during daylight.
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Trichomycterus nigroauratus, UFRJ 6034, live holotype, 50.1 mm SL; Brazil: São Paulo: Município de São José do Barreiro. Photo by W. J. E. M. Costa
Stefano Valdesalici and Holger Hengstler: Nothobranchius krammeri n. sp. (Cyprinodontiformes: Nothobranchiidae): a new annual killifish from the Meronvi River basin, northeastern Mozambique, pp. 187-194
Nothobranchius krammeri n. sp., a small annual killifish collected from a seasonal pool in Meronvi River basin, northeastern Mozambique, is described. It differs from all congeners by the following combination of characters: 13-15 dorsal fin rays; 14-15 anal fin rays; 24-27 scales in median lateral series; pelvic fin tips not reaching anus; male body and head scales light blue with pale red or orange margin; snout reddish; throat orange to yellow; frontal and superior portion of head reddish; anal fin yellowish with a pattern of narrow pale brown lines; caudal fin pale red with a small black seam along its outer margin, and a sharply delineated hyaline submarginal band. Based on coloration of males and morphological aspects, this new species belongs to the Nothobranchius melanospilus species group.
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Adult male of Nothobranchius krammeri n. sp. F1 about six months old (not preserved). Photo by W. Krammer
Wilson J. E. M. Costa: Redescription of Rivulus santensis (Teleostei: Cyprinodontiformes: Rivulidae), a killifish species from the Atlantic forest of southeastern Brazil, pp. 195-202
Rivulus santensis, a poorly known killifish species from the Atlantic forest of southeastern Brazil, is redescribed. It is endemic to an area encompassing the middle and lower rio Ribeira de Iguape basin and smaller coastal river basins of São Paulo and Paraná states. Rivulus santensis is distinguished from all other species of the genus by the colour pattern of the caudal fin in males, in which there is a dark grey to black stripe on the dorsal margin of the fin, and another stripe that is similar but distinctively wider on the ventral margin. It is similar to R. haraldsiolii by having both the snout elongated and slightly pointed in a lateral view. Rivulus santensis differs from R. haraldsiolii in possessing 16 rows of scales around the caudal peduncle and one or two minute contact organs per scale on the middle portion of the flank in males, in contrast to 14 scale rows and two to seven prominent contact organs per scale.
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Rivulus santensis, UFRJ 6299, male, 30.4 mm SL (some hours after collection): Brazil: São Paulo: Itanhaém. Photo by W. J. E. M. Costa
Gerald R. Allen and Mark V. Erdmann: A new species of damselfish (Chromis: Pomacentridae) from the Raja Ampat Islands, Papua Barat Province, Indonesia, pp. 203-208
A new species of pomacentrid fish, Chromis athena, is described from five specimens, 49.8-54.3 mm SL collected in 62 m depth at the Raja Ampat Islands of western New Guinea (Papua Barat Province, Indonesia). Diagnostic features include XIII,10 or11 dorsal rays; II,10 or 11 anal rays; 17-18 pectoral rays; 3 spiniform caudal rays; 13-14 tubed lateral-line scales; body depth 2.0-2.1 in SL, and a distinctive colouration consisting of a mainly blue-grey body with a bright yellow zone encompassing the nape and upper back above the lateral-line scales.
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Chromis athena, underwater photograph of anesthetized freshly collected holotype, 49.8 mm SL, Raja Ampat Islands, Indonesia. Photo by G. R. Allen
Gerald R. Allen, Peter J. Unmack and Renny K. Hadiaty: Two new species of rainbowfishes (Melanotaenia: Melanotaeniidae), from, western New Guinea (Papua Barat Province, Indonesia), pp. 209-224
Two new species of rainbowfishes are described from the southwestern Birds Head region of western New Guinea (Papua Barat Province, Indonesia). Melanotaenia ammeri n. sp. is described on the basis of 19 specimens, 46.5-82.2 mm SL, collected near Gusimawa Village, Arguni Bay. It is most closely related to M. kokasensis n. sp., also described as new from 25 specimens, 27.2-68.5 mm SL, collected near Kokas Village on the northern Fakfak Peninsula. The two species are easily distinguished on the basis of colour pattern: M. ammeri has a distinctive pattern of alternating mauve to greyish blue and yellow stripes and the colour pattern of M. kokasensis is dominated by a broad, black midlateral stripe. In addition, males of M. ammeri are significantly deeper bodied (maximum body depth as % of standard length 39.3 versus 34.5) than those of M. kokasensis. Analysis of genetic relationships based on cytochrome b sequences indicates a close relationship between the two species and demonstrates that they are part of the unique rainbowfish clade found mainly on the Vogelkop Peninsula and some offshore islands. The new species differed in their mean Kimura 2-parameter genetic divergences by 2.4% from each other. Both were between 5.4 and 5.6% divergent from M. parva, the next most closely related species that we obtained genetic data for.
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Melanotaenia ammeri, preserved male, holotype, 82.2 mm SL, Gusimawa, Papua Barat Province, Indonesia. Photo by G. R. Allen