)tn Judo - Pacifi~ Fish Conference oun a - e II denia ( vernb ~ 3 - t 1997 A ST ACTS Organized by Under the aegis of L'Institut français Société de recherche scientifique Française pour le développement d'Ichtyologie en coopération ' FI Fish Conference Nouméa - New Caledonia November 3 - 8 th, 1997 ABSTRACTS LATE ARRIVAL ZOOLOGICAL CATALOG OF AUSTRALIAN FISHES HOESE D.F., PAXTON J. & G. ALLEN Australian Museum, Sydney, Australia Currently over 4000 species of fishes are known from Australia. An analysis ofdistribution patterns of 3800 species is presented. Over 20% of the species are endemic to Australia, with endemic species occuiring primarily in southern Australia. There is also a small component of the fauna which is found only in the southwestern Pacific (New Caledonia, Lord Howe Island, Norfolk Island and New Zealand). The majority of the other species are widely distributed in the western Pacific Ocean. AGE AND GROWTH OF TROPICAL TUNAS FROM THE WESTERN CENTRAL PACIFIC OCEAN, AS INDICATED BY DAILY GROWm INCREMENTS AND TAGGING DATA. LEROY B. South Pacific Commission, Nouméa, New Caledonia The Oceanic Fisheries Programme of the South Pacific Commission is currently pursuing a research project on age and growth of two tropical tuna species, yellowfm tuna (Thunnus albacares) and bigeye tuna (Thunnus obesus). The daily periodicity of microincrements forrned with the sagittal otoliths of these two spceies has been validated by oxytetracycline marking in previous studies. These validation studies have come from fishes within three regions of the Pacific (eastem, central and western tropical Pacific). Otolith microincrements are counted along transverse section with a light microscope. Observations with a scanning electron microscope allow checking of the interpretation of readings made with light microscope. Several growth models are tested according to the results of these daily increment counts. A large tagging database provides independent validation of the growth models. From 1989 to 1992, 33523 yellowfin and 6796 bigeye were tagged, from which 3482 (10.4%) yellowfin and 602 (8.9%) bigeye were recaptured (as of October 1997). Growth models deduced from otolith readings are consistent with growth rates observed during the periods of liberty at sea (several days to 5 years) of tagged tuna. Furtherrnore, the tagging data aUow section of the model which describes the growth over a size range larger than the one provided with the otolith data. REPRODUCTIVE BEHAVIOUR OF JAPANESE TUBESNOUT, AUUCHTHYS JAPON/CUS. AKAGAWA 1., IWAMOTO T. & M. OKIYAMA Miyazaki University, Miyazaki, Japan Aulichthys japonicus is known as the only one species that copulates and hides the eggs in the sea squirts in Gasterosteiforrnes. Courtship and spawning behaviour of A. japonicus was observed under natural environment in Otsuchi Bay, Japan and in the aquarium, respectively. The males showed remarkable nuptial colouration (metallic green or blue) on their snout during the spawning season and established the territory on the wall of the harbour. They courted the gravid female approaching to them and tried to lead her to their territories by tail flagging. The females were significantly larger than the males. In the aquarium, the gravid females repeatedly looked into the sea squirts, Halocynthia roretzi. The males were swimming around them or watching them still. The female spawned the egg mass above the sea squirt and put them through the exhalent opening by her mouth. The eggs were attached to the atrium. Only for a few minutes after the spawning, all the males tried to copulate the female lying on their back beneath the female. Spawning behaviour and sexual dimorphism in size and colouration is discussed in comparison with other related species; Aulorhynchus flavidus, whieh is the other Aulorhynchid species, Hypoptychus dybowskii, having been considered as the most primitive in Gasterosteiforrnes, and Gasterosteid fishes. -A NEW SEABREAM (SPARIDAE, DENTICINAE) FROM OFF NEW CALEDONIA. AKAZAKI M. & B. SÉRET Akazaki Ichthyological Institute, Miyazaki, Japan The new species of yellow seabream caught from off New Caledonia differs its congeners from Japan, Okinawa, Europe and Africa, by its head length, eye diameter and suborbital width. The New Caledonian specimens have the typical dorsal fin count of the genus Dentex: XIII - 9. This new species of Dentex descrihed from New Caledonia may have a larger distribution: indeed, the seabream figured on plate 97 in " Illustrations of edible aquatic fauna of the south seas " (Kumada, 1941) as Taius tumifrons may he identical. If so, the" New Caledonian " species should also occurs in Australian waters and possibly in those of Japan as reported by Kumada. PRELIMINARY EXAMINATION OF GENETIC DIFFERENTIATION OF THE " KINUBARI " GOBY, PTEROGOB/US ELAPO/DES. AKIHITO, IKEDA Y. & Y. SUZAWA Imperial Palace, Tokyo, Japan P. elapoides is distributed from Hokkaido to Kyuushu in Japan and is also found in waters around the Korean Peninsula. There are two patterns of body coloration: one has 6 bands on the side of the body (Pacifie Ocean), the other has 7 bands (Sea of Japan). This geographic variation has never been studied in detail. Therefore, our objective was to c1arify possible genetic differentiation using electrophoresis. We compared two populations, one from Kanagawa Prefecture, Japan (Pacifie Ocean), and the other from Ishikawa Prefecture, Japan (Sea of Japan). Genetic variations were deterrnined for 23 allozymic loci relating to 12 enzymes and 1 non-enzymatic protein. Our results demonstrate that these two populations do show genetie variation (Nei's genetic distance, D=0.022). 3 MOLECULAR PHYLOGENY BETWEEN LOACH GOBY (RHYACICHTHYIDAE), FIVE SLEEPERS AND TWO GOBIES (GOBIIDAE) AND ONE WORM FISH (GUNNELICHTHYDAE). AKIHITO, KOBAYASHI T., IWATA A. & T. GOJOBORI Imperial Palace, Tokyo, Japan Based on character states of their cephaIic sensory canals and certain bones, Bostrychus sinensis and Oxyeleotris marmorata (Gobioidei: Eleotrididae) were considered to represent an ancestral gobioid morphotype (Akihito, Prince 1986). Using other morphological characters, Gill and Hoese (1993) hypotheesized that Odontobutis, Micropercops, and Perccottus represented the most primitive group of gobioid fishes (except for the Rhyacichthyidae); they erected the family Odontobutidae for these three genera. The purpose of our study is to hypothesize gobioid phylogeny using molecular data. About 800 bp of cytochrome b sequences from the following gobioid species will be analyzed using the percoid Lateolabrax japonicus as outgroup: Rhyacichthys aspro, Bostrychus sinensis. Eleotris fusca. Gunnellichthys monostigma. Micropercops swinhonis, Odontobutis obscura, Oxyeleotris marmorata, Tridentiger bifasciata and Tridentiger obscurus. The results will be compared with those ofAkihito, Prince (1986) and Gill and Hoese (1993). EFFECTS OF THE 1991 GULF WAR OIL SPILL ON REEF FISH ASSEMBLAGES. ALMARRI M. & F. KRUPP National Commission for WildIife Conservation and Development (NCWCD), Jubail, Saudi Arabia Following the 1991 Gulf War oil spil1, benthic and demersal fish assemblages 'were studied in nearshore areas between Ras az-Zor and Abu Ali and at five offshore locations north of Jubail, Saudi Arabia. This area has the highest fish species diversity anywhere in the Arabian Gulf. It was severely affected by the Gulf War oil spill, but coral reefs and reef associated biota escaped direct oil contamination. Upon first inspection in 1991, reef fish assemblages seemed to be in a reasonably healthy condition. However, a conclusive assessment of their status was hampered by a lack of comparative pre-war data. Additionally, in these high latitude reefs where many tropical fish species live close to their physicallimits, there are considerable natural fluctuations of population densities. Between 1992 and 1997 reef fishes were counted annually along 50 fi transect lines. AlI specimens of 20 mm total length and longer occurring one metre to each side and two metres above the transect were recorded. Counts taken in 1992 and 1993 gave similar results with an average of 34.0 species and 254.1 individuals per 100 m"2 transect (1993 data). In summer 1994, the average number of species increased by Il % and the number of specimens per transect almost doubled, indicating that fish assemblages had recovered from the effects of the oil spill. Similarly high or higher counts were obtained in subsequent years. A possible explanation is that the oil had no direct effect on fishes inhabiting these reef areas. However, as shown in other studies, planktonic eggs and larvae were affected by the oil slick on the water surface, resulting in lower levels of recruitment onto the reef in 1991 and 1992 and thus lower fish counts in the two subsequent years. 4 A REVISION OF ARNOGLOSSUS FROM THE WATERS AROUND NEW CALEDONIA. - AMAOKA K., MillARA E. & 1. RIVATON Laboratory of Marine Zoology, Faculty of Fisheries, Hokkaido University, Hakodate, Japan Species of the bothid genus Amoglossus collected from the waters around New Caledonia are reviewed. Seven species were identified including two new species: A. macrolophus, A. japonicus, A. elongatus, A. tenuis, A. polyspilus, A sp. 1 and A. sp. 2. A. sp. 1 is described from ten specimens collected from depth of 230-315m off southern New Caledonia. This species is unique in having the pelvic fins with seven rays. A. sp. 2 is described from two specimens collected from depths of 300-315m of the Chesterfield Plateau and the northwest