Volume 10, Issue 3, October 2005
Volume 10, Issue 3 – October 2005
Gerald R. Allen and Mark V. Erdmann: Chromis xouthos, a new species of damselfish (Pomacentridae) from the East Andaman Sea and Central Indian Ocean, pp. 89-94
Chromis xouthos is described from six specimens, 82.4-92.3 mm SL, collected at Pulau Weh, Aceh Province, Sumatra, Indonesia at a depth of 25 m. Diagnostic features include: XIII,12 dorsal rays; II,11 (rarely 12) anal rays; 19 (rarely 18) pectoral rays; 3 spiniform caudal rays; 16-17 tubed lateral line scales; 6-7+19-21 (total, 26-28) gill rakers on the first branchial arch; body depth 1.9-2.0 in SL; and colour in life mainly golden brown with a yellowish caudal fin and pale bluish-grey pelvic fins. It appears to be closely related to C. pembae of the western Indian Ocean and Red Sea, but exhibits apparent modal differences in the number of total gill rakers on the first branchial arch, tubed lateral line scales, and pectoral rays. The two species share similar colour patterns, although C. xouthos is overall golden brown compared with the dark brown ground colour of C. pembae.
Chromis xouthos, underwater photograph of adult, approximately 120 mm total length, Pulau Weh, Indonesia. Photo by G. R. Allen
Gerald R. Allen and John E. Randall: A new species of damselfish (Pomacentrus: Pomacentridae) from Fiji, pp. 95-102
Pomacentrus microspilus is described from 48 specimens, 16.7-73.6 mm SL, collected at Fiji. It is distinguished from similar species, particularly P. brachialis, P. imitator, P. nagasagiensis, and P. philippinus, on the basis of colour pattern and modal differences in certain meristic features. All of these species have a dark brown to grey-brown ground colour and a prominent black spot covering the pectoral fin base. However, P. microspilus is unique in having a triangular, dorsal extension of the pectoral spot, a thin pale marking above the eye, and a small black spot at the base of the posterior dorsal fin rays in adults. The new species is associated with silt-affected coral reefs at depths between about 2 to 30 m.
Pomacentrus microspilus, underwater photograph of juvenile, approximately 45 mm total length, Ovalau, Fiji. Photo by G. R. Allen
Jürgen Herler and Helge Hilgers: A synopsis of coral and coral-rock associated gobies (Pisces: Gobiidae) from the Gulf of Aqaba, northern Red Sea, pp. 103-132
Field investigations in the Gulf of Aqaba, northern Red Sea (Dahab, Sinai, Egypt) revealed 21 species in seven genera of gobiid fish associated with corals and/or coral rock. Three as yet undetermined species of Gobiodon (G. sp.1, 2 and 3) were found to be new for the Red Sea. Like the congeneric G. citrinus, G. histrio, G. reticulatus and G. rivulatus, they are obligate dwellers of Acropora corals. Among the other genera, Bryaninops yongei significantly differs from its congener B. ridens in live coloration as well as by its preference for Cirripathes sp., while the latter obligatorily inhabits Millepora dichotoma. A third species, B. natans, exhibits hyperbenthic behaviour, violet eyes and a yellow belly on the otherwise transparent body and is commonly associated with Acropora loripes and A. squarrosa. The five Eviota species examined were less specialized and associated with live corals of various growth forms and/or with coral rock. Paragobiodon echinocephalus showed very low occupation rates of the highly abundant Stylophora pistillata and was mostly found in small breeding pairs. Within the genus Pleurosicya, P. micheli is more slender than P. prognatha and shows a distinct longitudinal red internal stripe, while the latter is transparent with a few brown speckles in life. Pleurosicya micheli inhabits massive scleractinians, whereas P. prognatha is found in Acropora. Priolepis semidoliata was rare and associated with coral rock. Weak associations with scleractinians were also found in Trimma avidori, which was common but prefers steep or overhanging substrates mostly consisting of coral rock. Trimma mendelssohni prefers coral rock caves.
Coloration of Gobiodon reticulatus from the Gulf of Aqaba, northern Red Sea