aqua International Journal 15(3)
Volume 15, Issue 3
20 July 2009
Volume 15, Issue 3 – 20 July 2009
Gerald R. Allen and Mark V. Erdmann: Two new species of damselfishes (Pomacentridae: Chromis) from Indonesia, pp. 121-134
Two new species in the pomacentrid genus Chromis are described from Indonesian seas. Chromis albicauda is described from nine specimens, 79.6-133.7 mm SL, collected at Nusa Penida, off the east coast of Bali. It closely resembles C. analis, which ranges widely in the western Pacific. Both species have a similar yellow colouration, but C. albicauda has an abruptly white caudal fin compared to the yellow caudal of C. analis. It also differs in having a more densely scaled preorbital and a suborbital margin that is obscured by scales. Additional differences include a black blotch covering the anal opening, a larger size, and taller dorsal spines. The other new species, Chromis unipa, is described from five specimens, 42.8-50.4 mm SL collected in 45-60 m in Cenderawasih Bay, Western Papua, Indonesia. Diagnostic features include XIV,11 dorsal rays; II,11 anal rays; 18 pectoral rays; 3 spiniform caudal rays; 14-17 tubed lateral-line scales; body depth 2.0-2.2 in SL, and a distinctive colouration of alternating blue-grey and brassy yellow stripes on the side of the body, blue-grey ventrally on the head and body, bluish fins except for brown basal portion of the caudal fin, and a prominent black spot on the anal fin. It belongs to a complex of deep-dwelling Chromis possessing 14 dorsal spines and it appears most similar to C. degruyi, known from 85-120 m depths in the Caroline Islands. Although both species have similar counts for pectoral-fin rays, tubed lateral-line scales, and gill rakers, they differ with respect to modal numbers of soft dorsal and anal-fin rays as well as body depth and snout length. They also exhibit significant colour pattern differences.
Gerald R. Allen and Mark V. Erdmann: Heteroconger mercyae, a new species of garden eel (Congridae: Heterocongrinae) from West Papua, Indonesia, pp. 135-142
A new species of heterocongrine garden eel is described from West Papua, Indonesia based on 13 specimens, 106.3-678.1 mm TL. It differs from other members of the genus by its distinct colour pattern, consisting of zebra-like black and white barring on the head grading to a complex black and white maze pattern on the body and a combination of features that include dorsal fin origin anterior to gill opening, pterygoid teeth present, body depth at gill opening 28.8-35.2 percent of head length, 62-71 (mean = 65) preanal vertebrae, 204-213 (mean =207.4) total vertebrae, and 63-69 (mean = 65.7) preanal lateral-line pores. A key is provided for the Indo-west Pacific species of Heteroconger.
Stefano Valdesalici, Marc Bellemans, Kiril Kardashev, Alexander Golubtsov: Nothobranchius nubaensis (Cyprinodontiformes: Nothobranchiidae) a new annual killifish from Sudan and Ethiopia, pp. 143-152
A new species of annual killifish, Nothobranchius nubaensis, is described based on specimens collected from ephemeral water bodies in central Sudan and south-west Ethiopia. The new species is distinguished from the other members of the Nothobranchius ugandensis species group by the following combination of characters: 17-19 dorsal fin rays; 17-19 anal fin rays; 29-30 scales in median lateral series; dorsal and anal fins in males with short filamentous rays; pelvic fins short, tips reaching the anus; orange red head with three distinct oblique bars on the operculum; dorsal fin light blue with a pattern of irregular orange-red spots and elongated yellow spots in distal areas; anal fin yellow, light blue at base, with a pattern of orange-red spots; pelvic fins yellow with a pattern of orange-red spots; pectoral fins orange-red with a light blue margin; caudal fin orange-red with short pale or dark red lines, extending from fin base onto fin rays.
Flávio C. T. Lima & Leandro M. Sousa: A new species of Hemigrammus from the upper rio Negro basin, Brazil, with comments on the presence and arrangement of anal-fin hooks in Hemigrammus and related genera (Ostariophysi: Characiformes: Characidae), pp. 153-168
A new species of Hemigrammus is described from the rio Tiquié, a tributary of the rio Uaupés, upper rio Negro basin, Amazonas, Brazil. The new species can be distinguished from all congeners by the presence (in life specimens) of an orange blotch, situated between the two dark humeral blotches, immediately ahead and slightly above the posterior, darker second humeral blotch. Additionally, the new species can be distinguished from all congeners, except H. haraldi, H. luelingi, H. neptunus, H. ocellifer, H. pretoensis, and H. pulcher, by the possession of two humeral blotches. It can be distinguished from these species by lacking a blotch on the caudal peduncle (vs. caudal peduncle blotch present). A monophyletic group within Hemigrammus, the Hemigrammus ocellifer species-group, encompassing the new species, plus Hemigrammus ocellifer, H. neptunus, H. guyanensis, H. luelingi, H. pulcher, and H. haraldi, is proposed, based on the shared possession of a derived hook arrangement in the anal-fin of mature males and some pigmentary features. A discussion of the hooks’ presence and arrangement within the genus Hemigrammus and in the related genera Parapristella and Petitella is presented, based on an extensive examination of specimens belonging to these genera. It is hypothesized that the close association between anal-fin hooks and dense, presumably secretory tissue, found in all Hemigrammus, Parapristella, Petitella, and Hyphessobrycon species examined, is a mechanism to facilitate cell rupture, enhancing the setting free of cell secretions.
|Dimensions||26.6 x 20.3 x 0.3 cm|
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