Volume 4, Issue 3, April 2001
Volume 4, Issue 3 – April 2001
John E. Randall and Richard L. Pyle: Three New Species of Labrid Fishes of the Genus Cirrhilabrus from the Islands of the Tropical Pacific, pp. 89-98
The following three new wrasses of the genus Cirrhilabrus are described from islands of the central and western Pacific: C. claire, from two specimens, an 84.0 mm male and a 72.8 mm female taken in 92 m off Rarotonga, Cook Islands; C. earlei from nine specimens, 45.1-69.1 mm, collected in 80-92 m from Palau; and C. walshi from two male specimens, 56.0-62.8 mm, from 37-46 m off Taumu Bank, Tutuila, American Samoa. Colour illustrations are presented, and comparisons are made with similar species.
Aquarium photograph of holotype of Cirrhilabrus walshi, BPBM 37201, male, 62.8 m SL, Tutuila, American Samoa. Photo by R. Pyle
Eugenio Alberto Aragón-Noriega and Luis Eduardo Calderon-Aguilera: Age and growth of shrimp (Decapoda: Penaeidae) postlarvae in the Upper Gulf of California, pp. 99-104
Postlarvae are a critical stage in the life cycle of the shrimp because catches depend on the strength of this year class. To assess the growth of postlarvae in the upper Gulf of California, intensive sampling was performed during a complete tide cycle from July 12-27, 1995 and from June 30 to July 16, 1996, simultaneously in two locations: one off the mainland (Santa Clara) and one off the peninsula (San Felipe). A 10-minute trawl was performed every hour during the flood tide (day and night). The total length of each individual postlarva was determined by measuring it with the aid of a calibrated micrometer (0.001 mm). Two species were found: Farfantepenaeus californiensis and Litopenaeus stylirostris, known as brown and blue shrimp, respectively. Subsequently these two species were reared to assess their age from their length. Wild postlarvae range from 7 to 13 mm and average 9 mm. It was concluded that wild postlarvae are recruited to the upper Gulf of California 20 to 28 days after being spawned in oceanic waters.
Map of the study area showing fishing ports and sampling locations. Bathymetry indicated in metres
Luiz A. Rocha, Richardo Z. P. Guimarães, and João L. Gasparini: Redescription of the Brazilian Wrasse Thalassoma noronhanum (Boulenger, 1890) (Teleostei: Labridae), pp. 105-108
Thalassoma noronhanum is a poorly known wrasse that inhabits tropical reefs of the western South Atlantic. The species is found from Parcel de Manuel Luiz reefs to the coast of São Paulo, and at all Brazilian oceanic islands. It inhabits rocky and coralline algae reefs, and was collected from the shoreline to depths of 60 m. Juveniles are known to clean other fish, and adult females form harems dominated by a few terminal-phase males.
Large female Thalassoma noronhanum. Note the bicolored body (typical initial phase) with blue lines on head radiating from eye (typical terminal phase). Photo by G. R. Allen
João Luiz Gasparini, Luiz A. Rocha, and Sergio R. Floeter: Ptereleotris randalli n. sp., a new dartfish (Gobioidei: Microdesmidae) from the Brazilian Coast, pp. 109-114
Ptereleotris randalli n. sp., the third species of the genus from the Western Atlantic, is described from the Brazilian Coast. It differs from P. helenae, its North Atlantic sister species, in having the second dorsal and anal fins comparatively lower and slightly more elevated anteriorly; a shorter caudal fin with the fifth and sixth rays prolonged as filaments; and shorter pelvic fins which are about the same length as the pectorals. This species is known from Parcel de Manuel Luiz (00°52’S, 44°16’W), NE Brazil to Alcatrazes Archipelago (24°06’S, 45°42’W), SE Brazil, in depths between 8 and 60 m.
Holotype of Ptereleotris randalli n. sp., photographed in an aquarium immediately after collection. Photo by J. L. Gasparini
John E. Randall, Richard L. Pyle, and Robert F. Myers: Three Examples of Hybrid Surgeonfishes (Acanthuridae), pp. 115-120
Three hybrids of surgeonfishes (Acanthuridae) are documented: Acanthurus nigricauda x A. olivaceus from the Marshall Islands, A. olivaceus x A. tennentii from Bali, Indonesia, and Zebrasoma rostratum x Z. scopas from Kiritimati (formerly Christmas Island), Line Islands.
Zebrasoma rostratum, Kiritimati (Christmas Island), Line Islands. Photo by J. E. Randall
Gerald R. Allen: Lentipes multiradiatus, a New Species of Freshwater Goby (Gobiidae) from Irian Jaya, Indonesia, pp. 121-124
A new species of freshwater gobiid, Lentipes multiradiatus, is described on the basis of a single male specimen, 27.4 mm SL, collected from the Cyclops coast, near Jayapura, Irian Jaya Province, Indonesia. The species is characterised by a combination of features that include: dorsal rays VI-I,10; anal rays I,10; pectoral rays 20; first dorsal fin connected basally to second dorsal fin; four oculoscapular sensory pores; and the absence of both bilobed urogenital structures and a sac of replacement teeth on the upper jaw. It is the only species of Lentipes, except for L. watsoni from southern Papua New Guinea, in which males possess a small black spot at the beginning of the second dorsal fin.
Aquarium photograph of male holotype of Lentipes multiradiatus, 27.4 mm SL, Danyamo Stream, Irian Jaya, Indonesia