Volume 17, Issue 3, 10 July 2011
Volume 17, Issue 3 10 July 2011
Leonardo A. Abitia-Cárdenas, Xchel G. Moreno-Sánchez, Deivis S. Palacios-Salgado and Ofelia Escobar-Sánchez: Feeding habits of the convict surgeonfish Acanthurus triostegus (Teleostei: Acanthuridae) on the Los Frailes reef, Baja California Sur, Mexico, pp 121-126
Studies of the feeding habits of reef-inhabiting herbivorous species are important since they are the first level in the trophic chain between primary producers and consumers. This study is the first contribution to determine the diet of the convict surgeonfish Acanthurus triostegus from the Los Frailes reef, Baja California Sur, Mexico. We describe qualitative and quantitatively the trophic spectrum of 50 A. triostegus individuals, using the traditional methods of frequency of occurrence and weight, as well as the index of relative importance. Overall, we identified 35 food components, of which 18 were algae of the Class Rhodophyceae, 10 of the Chlorophyceae and six Phaeophyceae. We determined that A. triostegus is a strict diurnal herbivore, which mainly feeds on the green alga Ulva linza, and even though it is a species with a wide geographic distribution, its behavioral feeding pattern is homogeneous.
Main food compounds of Acanthurus triostegus, presented as percentage weight, frequency of occurrence and index of relative importance (%IRI). * NIOM (non-identified organic matter).
Richard Winterbottom: Six new species of the genus Trimma (Percomorpha; Gobiidae) from the Raja Ampat Islands, Indonesia, with notes on cephalic sensory papillae nomenclature, pp. 127-162
Recent (2010) fieldwork in the Raja Ampat Islands of Indonesia resulted in the collection of seven undescribed species of Trimma, six of which are described here. Two of these are currently only known from these islands, the others are known from other parts of the western Pacific. Trimma cheni n. sp. is distinguished from other species of Trimma in having 8-9 scales in the predorsal midline, 2-3 scales on the opercle, an elongate second dorsal spine reaching posteriorly to the bases of rays 1-4 of the second dorsal fin, middle pectoral fin rays branched, fifth pelvic fin ray branched once, a dark basal stripe in the dorsal fins, scale pockets indistinctly outlined with darker pigment, and, in life, two red to orange bars across the cheek and three diffuse yellow stripes on the body (most obvious along the caudal peduncle). It has been recorded from Palau, the Philippines, and Sulawesi and Flores in Indonesia. Trimma erdmanni n. sp. has a reddish-orange body with a dark red lateral stripe with darker borders on the body which extends anteriorly onto the head, where it bifurcates, and there is a thin longitudinal light stripe below the eye. It usually lacks scales in the predorsal midline, the second spine of the first dorsal is elongated, there are 9 dorsal and 8 anal rays, a single branch in the fifth pelvic fin ray, and 19-22 gill rakers on the first gill arch. The species is known from the Raja Ampat islands, the Hermit Islands and Madang (Papua New Guinea), and from photographs from El Nido, Palawan Island and Davao Gulf, Mindanoro, Philippines. Trimma habrum n. sp. has a bony interorbital width equal to the pupil diameter, 8-9 scales in the predorsal midline, 14 unbranched pectoral fin rays, an unbranched fifth pelvic fin ray, no basal membrane joining the fifth pelvic fin rays across the midline, usually a single full row of cheek scales, and scales on the upper two-thirds of the opercle. The fresh colouration is diagnostic: a pale translucent dorsum with light yellow blotches and the base of each element of the dorsal fin surrounded by a red spot, a thin red bar along the posterior margins of the hypurals, no dark pigment at all on the hypural region of the peduncle, and a darkly pigmented covering to the dorsal margins of the swim bladder, neural sheath, and the brain. It is currently known only from a single collection made at Kerou Island, Fam Islands in Raja Ampat, Indonesia. Trimma haimassum n. sp. is characterized by a relatively deep body, numerous irregular scales with about 30 lateral rows and over 15 scales in the anterior transverse series, a fifth pelvic fin ray that branches twice dichotomously, usually a somewhat elongate second dorsal spine, no predorsal, cheek or opercular scales, a moderately wide bony interorbital with a fleshy median ridge between the eyes, and a dermal ridge anterior to the first dorsal spine. There is a red spot or elongate blotch above the opercle in live and fresh material, and the dorsal surface of the snout has a reticulated dark pattern, with dark transverse stripes over the dorsal margin of the orbit. The species is known from south-western Sulawesi north to Palawan and eastwards to the Solomon Islands. Trimma papayum n. sp. is unique among the described species of the genus in having a one-third pupil diameter black ocellated spot on and just behind the fourth dorsal fin spine. It has 9 dorsal and 8 anal fin rays, a single branch point in the fifth pelvic fin ray, 10-11 anterior and 8-9 posterior transverse scale rows, 5-10 scales in the predorsal midline, and a single row of 3 scales on the upper margin of the opercle. Freshly collected specimens are orange red in overall colouration, with scattered diffuse yellow spots. The species is known only from Indonesia, at Maumere, Flores and Kawe Island, Raja Ampat. Trimma xanthochrum n. sp. is characterized by a wide interorbital region (80-100% pupil diameter), a second dorsal spine usually reaching posteriorly to between the bases of the second to third dorsal fin rays, 15-16 pectoral rays usually with 7-8 branched rays, vertical rows of sensory papillae below eye of 2-3 papillae in rows 1-4 and 4-5 in row 5, a caudal blotch which has a lower half about two-thirds the width of the upper half, and usually an overall yellowish body with yellow at least proximally in the caudal fin. It is currently known with certainty only from the Raja Ampat islands.
Left lateral view of Trimma cheni, 22.3 mm SL male paratype, ROM 85085, Mutus Island, Raja Ampat. Photo by R. Winterbottom.
Doug Hoese, Koichi Shibukawa and Jiro Sakaue: A redescription of the gobiid fish Cryptocentrus sericus Herre, with clarification of Cryptocentrus leptocephalus and C. melanopus, pp. 163-172
Cryptocentrus sericus Herre is redescribed from the holotype and recently collected material in the Australian Museum, Museum and Art Gallery of the Northern Territory and Western Australian Museum. The species is distinctive in coloration, presence of predorsal scales, and in fin-ray and scale counts. We provide a comparison with other species with similar morphological features. Illustrations are provided of C. sericus and its most similar species, C. fasciatus. A brief comparison and figures are provided for separating the related C. leptocephalus and C. melanopus. These two species have been confused and frequently misidentified.
Freshly collected specimen of Cryptocentrus sericus, AMS I.19474-003; note that as the specimen was speared the image has been modified and the belly and upper part of the pelvic fin is distorted.
Renny K. Hadiaty and Gerald R. Allen: Glossamia arguni, a new species of freshwater cardinalfish (Apogonidae) from West Papua Province, Indonesia, pp. 173-180
A new species of freshwater cardinalfish, Glossamia arguni, is described on the basis of 13 specimens, 12.8-102.3 mm SL, collected in November 2010 from streams in the Arguni Bay area of the Bird’s Neck region of Kaimana Regency, West Papua Province, Indonesia. It is most similar to G. sandei, which ranges widely in south-central New Guinea from the Purari River of Papua New Guinea to Lake Yamur in Papua Province of Indonesia. Both species are characterised by relatively small scales and a barred colour pattern. However, G. arguni n. sp. has fewer lateral-line scales (43-45 vs. 46-50), and five broad bars on the sides compared with 8-12 narrow bars in G. sandei. The new species also has nine soft dorsal rays compared to the usual count of 10 for G. sandei.
Aquarium photograph of Glossamia timika, approximately 90 mm SL, Timika, Papua Province, Indonesia. Photo by G. R. Allen.