Volume 4, Issue 4, August 2001
Volume 4, Issue 4 – August 2001
Gerald R. Allen: Description of Two New Gobies (Eviota, Gobiidae) from Indonesian Seas, pp. 125-130
Two new species of Gobiidae are described from Indonesia. Eviota raja is described from 16 specimens, 12.7-23.8 mm SL, collected at the Raja Ampat Islands, Irian Jaya Province. It is closely related to E. bifasciata, a sympatric species that is distributed across the Indo-Australia Archipelago. The two species differ in colour pattern, as well as counts for segmented rays in the second dorsal fin and lateral scale rows (usually 9 and 22 respectively for E. bifasciata and 10 and 25 in E. raja). The second new species, Eviota mikiae, is described on the basis of 9 specimens, 12.6-19.1 mm SL, collected at Pulau Weh, northern Sumatra. It is similar in appearance to E. pellucida of the western Pacific, but differs in having more segmented rays in the second dorsal fin, (9 versus a usual count of 8), more branches on the fourth pelvic fin ray (modally 8 versus 5), ad fewer segments between branches on the fourth pelvic fin ay (1 versus 5).
Underwater photograph of Eviota raja, about 23 mm SL, in 8 m depth, Pef Island, Raja Ampat, Indonesia. Photo by G. R. Allen
John E. Randall and Aharon Miroz: Thalassoma lunare x Thalassoma ruepellii, a Hybrid Labrid Fish from the Red Sea, pp. 131-134
A hybrid of the endemic Red Sea labrid fish Thalassoma ruepellii (Klunzinger) (identified as T. klunzingeri Flower and Steinitz by most recent authors) and the wide-ranging Indo-Pacific T. lunare (Linaeus) is documented. Colour illustrations of the hybrid, the parent species, and the young and subadult of T. rueppellii are presented. The hybrid specimen (BPBM 38478, 247 mm SL) is deposited in the Bishop Museum, Honolulu, Hawaii.
Thalassoma lunare x T. rueppellii, Corald World, Eilat, Gulf of Aqaba, Red Sea. Photo by J. E. Randall
Shelley Walker and Francisco J. Neira: Aspects of the reproductive biology and early life history of black bream, Acanthopagrus butcheri (Sparidae), in a brackish lagoon system in southeastern Australia, pp. 135-142
Aspects of the reproductive biology and early life history of black bream (Acanthopagrus butcheri) in the Gippsland Lakes, a large brackish lagoon system in southeastern Australia, are described. Trends in mean gonadosomatic indices of males and females between November 1993 and March 1996 indicate that spawning occurred between October and February, with a peak in October-November when water temperatures were 15-22°C. Larvae (4.6-11.2 mm body length (BL)) were caught in shallow brackish ponds in November 1996 ad January 1997 and possess the typical sparid characteristics. Notochord flexion in larvae occurs at 4.6-6.0 mm BL, while early juveniles settle from about 13 mm BL. Ageing of black bream showed that the youngest sexually mature male (15.6 cm fork length (FL)) and female (15.9 cm FL) were 3+ year olds. The ability of black bream to complete their life cycle within estuarine environments appears to be unique amongst members of the Sparidae worldwide.
Larvae and early juvenule of Acanthopagrus butcheri from the Gippsland Lakes, south-eastern Australia. (a) 4.64 mm BL early flexion larva. (b) 5.90 mm BL flexion larva. (c) 8.84 mm BL early postflexion larva. (d) 11.35 mm BL postflexion larva; note forming third anal fin spine. (e) 13.68 mm BL early juvenile; myomeres and forming scales omitted. Illustrated by F. J. Neira.
Gerald R. Allen: Two New Species of Cardinalfishes (Apogonidae) from the Raja Ampat Islands, Indonesia, pp. 143-149
Two new species of apogonid fishes are described from the Raja Ampat Islands, off western New Guinea (Indonesian province of Irian Jaya), based on specimens collected during a Conservation International Survey in March-April 2001. Apogon leptofasciatus is described from three specimens, 48.2-50 mm SL, collected from a depth of 15 m. It is most similar to A. nigrocinctus Smith and Radcliffe (northern Australia to the Philippines) and A. jenkinsi Evermann and Seale (Australia to Japan), both of which possess similar black markings on the dorsal fins and caudal fin base. However, adults of these species lack narrow stripes on the upper body, and A. jenkinsi also differs in having a black spot on each side of the nape. The new species further differs from these two species in having fewer developed rakers on the first branchial arch (18 versus 22-25). Apogon oxygrammus is described on the basis of three specimens, 30.8-38.7 mm SL, collected from a depth of 46 m. It differs from all known species in the genus on the basis of colour pattern (overall whitish with a tapering black mid-lateral stripe that extends onto the caudal fin) and jaw dentition (enlarged teeth in relatively few rows).
Underwater photograph of holotype of Apogon leptofasciatus, 48.2 mm SL. Wruwarez Island, Raja Ampat Group. Photo by G. R. Allen
Victor G. Springer and Gerald R. Allen: Ecsenius ops, from Indonesia, and E. tricolor, from Western Philippines and Northwestern Kalimantan, New species of Blenniid Fishes in the Stigmatura Species Group, pp. 151-160
Based on additional material and numerous colour photographs taken in the field, Ecsenius melarchus, as treated by springer (1988), is shown to comprise three species, two of which are described as new. We hypothesize that six species within Ecsenius (E. stigmatura, E. melarchus, E. ops n. sp, E. tricolor n. sp., E. midas, and E. lividanalis) form a monophyletic clade, the Stigmatura (E. bicolor, E. namiyei) is the sister group of the Stigmatura group. The Stigmatura group comprises a trichotomy of two monospecific branches and the Stigmatura complex, which comprises an unresolved polytomy of E. melarchus, E. stigmatura, E. ops, and E. tricolor. Aspects of the distribution of the Stigmatura complex species are discussed with regard to Huxley’s Line.
Ecsenius melarchus, Church Reef, Borneo (ca. 04°41'N, 118°39'E). Photo by G. R. Allen
Luiz A. Rocha and Ricardo S. Rosa: Halichoeres brasiliensis (Bloch, 1791), a valid wrasse species (Teleostei: Labridae) from Brazil, with notes on the Caribbean species Halichoeres radiatus (Linnaeus, 1758), pp. 161-166
Halichoeres brasiliensis (Bloch, 1791), previously considered to be a junior synonym of H. radiatus (Linnaeus, 1758), is a valid species. It differs from H. radiatus by having 19-21 instead of 21-23 gill rakers, lacking four whitish blotches on the dorsum, and having a blue instead of a yellow margin on the caudal fin. The two species have allopatric distributions: H. brasiliensis is found on the Brazilian continental shelf and at Trindade Island, whereas the range of H. radiatus comprises the Caribbean, Gulf of Mexico, Florida, Bermuda, and the Brazilian oceanic islands of Fernando de Noronha, Atol das Rocas, and St. Paul’s Rocks.
Adult male Halichoeres brasiliensis (ca. 190 mm SL), aquarium photo. Photo by J. L. Gasparini
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