Volume 16, Issue 4 – 15 October 2010

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Abstract

Bathygobius is currently represented by three species in the western Atlantic (B. soporator, B. curacao and B. mystacium) based on diagnostic morphological features. Our combined genetic and morphological analyses indicate that there are at least six species of Bathygobius comprising eight genetic lineages in the western Atlantic. Two lineages are identified as B. curacao and B. mystacium. Four lineages possess characters that would previously have led to their identification as B. soporator. Two of those are morphologically indistinguishable and are recognized here tentatively as a single species, B. soporator. A third “B. soporator” lineage is distinct, and Gobius lacertus is resurrected here as Bathygobius lacertus for that lineage. The fourth “B. soporator” lineage is also distinct and is described as a new species. Two other closely related genetic lineages are morphologically indistinguishable and are treated as a single new species. Redescriptions of B. soporator, B. mystacium and B. curacao are provided. Comments are made on the identification of larval Bathygobius from Belize.

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Bathygobius antilliensis, holotype, 46 mm SL, female, Hatillo, Puerto Rico, DNA #PR1313, AMNH 251650. A, longitudinal pattern of pigment on first dorsal fin; B, upper, complete row of 7-8 blotches, row terminating just anterior to basicaudal markings; C, lower, incomplete row of 3 (rarely 4) blotches row usually terminating anterior to origin of anal fin. Photo by R. Chabarria. Image editing by L. Tornabene.

Gerald R. Allen, Mark V. Erdmann and Alison M. Hamilton: Hoplolatilus randalli, a new species of sand tilefish (Pisces: Malacanthidae) from the tropical western Pacific with comments on the validity of H. luteus, pp. 171-186

Abstract

Hoplolatilus randalli n. sp. is described on the basis of 13 specimens, 46.7-158.2 mm SL, collected at the Banda Islands and West Papua in Indonesia, Luzon in northern Philippines, Palau and Yap in Micronesia, and the Solomon Islands. The species has previously been confused with H. fronticinctus Günther, a closely related species that is restricted to the Indian Ocean from eastern Africa to the East Andaman Sea. The two species can be distinguished by basic colour differences, particularly the predominately greenish colour of H. randalli n. sp. and mainly bluish hue of H. fronticinctus. They also differ in caudal fin lobe shape; both species have an emarginate caudal fin, but the posterior edge of each lobe is slightly convex in H. randalli n. sp. and straight in H. fronticinctus. In addition, H. randalli n. sp. has longer dorsal spines (last spine 2.5-3.0 vs. 3.5-4.1 in HL) and longer soft dorsal rays (longest ray 1.1-1.4 vs. 1.5-1.7 in HL). Genetic data are also provided that confirm its validity. Additionally, we include comprehensive evidence (morphological, genetic, and ontogenetic colour pattern differences) for the recognition of H. luteus, which was recently considered a junior synonym of H. fourmanoiri.

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Underwater photographs of Hoplolatilus randalli n. sp. approximately 150 mm SL, Triton Bay, West Papua, Indonesia. Photos by G. R. Allen.

Tyson R. Roberts: Barbus sensitivus, a new species with extensive pitlines from the Sanaga River (Teleostei: Cyprinidae), pp. 187-196

Abstract

Barbus sensitivus new species, from the Sanaga River in Cameroon, West Africa, has a much more slender caudal peduncle than any other small African barb. It also has extensively distributed exposed pitline organelles in pit lines on the head and scales, illustrated here by scanning electron micrographs. Similar pit lines and pitline organelles evidently occur in various other Old World barbs assigned to various genera in Africa and Asia but adequate comparative studies including SEM observations are not available to permit their comparison and identification. None of the species previously described are very similar to this new species. The pitline organelles of B. sensitivus n. sp. have exposed or free neuromasts. Their sensory modality presumably is mechanosensory. Extensively distributed in large pit lines on the head and body of adult B. sensitivus n. sp., they are similar to lateral line neuromast organs in advanced larvae of Cyprinus carpio, Gnathopogon elongatus caerulescens, and Danio rerio. They are most concentrated on the ventrolateral part of the head, which has about 3000 of them, most bearing 20 to 100 kinocilia up to 7 micra long and 0.4 micra in diameter. Pit lines with smaller pitline organelles and fewer kinocilia occur in rows on the scales of the body and on the dorsal surface of the head but are absent from the fins. Their presence in adult B. sensitivus new species might represent a neotenic retention. In larval Gnathopogon elongatus caerulescens they facilitate detection of tiny planktonic prey such as Artemia when feeding under reduced light conditions.

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Barbus sensitivus, 40.6 mm female holotype, Sanaga River at Belabo, Cameroon (CAS 95344). Specimen oriented obliquely in order to show the pit lines on the undersurface of the head and the genital pad to better effect. Photo by J. Fong

Michel Bariche: Champsodon vorax (Teleostei: Champsodontidae), a new alien fish in the Mediterranean, pp. 197-200

Abstract

The Indo-Pacific gaper Champsodon vorax is reported for the first time from the Mediterranean Sea, off the coast of Lebanon. This new alien species is considered to have established a population along the Levantine basin in the eastern Mediterranean Sea. A detailed description of the Mediterranean specimens is provided.

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Champsodon vorax collected from Lebanon. 93.04 mm SL, AUBM OS3673