| Summary: | 碩士 === 國立臺灣大學 === 動物學研究所 === 90 === Abstract
The grenadiers (Family: Macrouridae) is one of the major group of benthopelagic fishes. Grenadiers occupy all oceans, except the high Arctic, and almost all basins with deep oceanic connections; none normally occur in depths shallower than found at abyssal depths. One species to more than 6000m, most species are found between 200m and 2000m (Iwamoto, 1990). At present, Grenadiers are approximately divided into 4 subfamilies, 38 genera and 327 species in the world. According to "Fishes of Taiwan" (Shen et al, 1993), there were 1 subfamily, 5 genera and 19 species occurred in Taiwan. The present study attempted to review this group of fish by re-examining previous deposited specimens and re-collecting new specimens from deep sea bottom trawler fisheries from 300-800 meters in north-eastern and south-western waters near Tashi, Nanfanao and Tungkang . Our preliminary study results obtained a total number of 2 subfamilies,11 genera and 40 species in which 19 species are new records and 3 are new species .They include three new species of Caelorinchus leptorhinus ,C.ephippins and C.logispinosus, and new records of 19 species: Gadomus coletti, Bathygadus antrodes, B.nipponicus, B.garretti, Hymenogadus gracilis, Hymenocephalus lethonenus, Nezumia condylura, Pseudoctenurous septifer, Kumba japonica, Ventrifossa longibarbata , V.macroptera, V.rhipidodorsalis V.saikaiensis, V.Lucifer, V.divergens, V.atherodon, C.productus, C.longissimus and C.asteroids.
Due to the difficulty and the divergence of character’s identification, the classification of this group of fish have many synonymous, misidentification and different classification system problems. The diagnostic key and the specimen color photos of each species are provided.
Additionally, the phylogenetic relationship of these 11 genera and 40 species were constructed using both phenetic and cladistic methods. Using 91 morphological characters to construct the phylogenetic relationships by phenetic (NTSYS) and cladistic (Henning 86).In conclusion:the subfamily Bathygadinae, Macrouridae, genus Caelorinchus and Hymenogadus-Hymenocephalus group are surely four monophyletic groups.The cladistic analysis shows Bathygadinae is more primitive than other taxa and Caelorinchus is the most specialize group for Macrouridae. Macrourinae and Bathygadinae are sister group. The relationship for Ventrifossa is a monophyletic group ; Hymenogadus and Hymenocephalus reach the genus level; Nezumia and Coryphaenoides are sister group; Kumba, Pseudoctenurous, Malacocephalus and Ventrifossa are very close in phenetic analysis. The phylogeny of Ventrifossa is not a monophyletic group ; Hymenogadus and Hymenocephalus not reach the genus level; Kumba ,Pseudoctenurous , Malacocephalus, Nezumia and Coryphaenoides are still unresolved in cladistic analysis. The difference for Oxymacrurus, Oxygadus, Paramacrurus and Quincunica of Caelorinchus are not reach the subgenus level in phenetic and cladistic analysis. So in the present study that the rank of subgenus for Caelorinchus differ from the generally-acknowledged system.
The thesis also analysis the distribution and abundance data of macrourids from the waters around Taiwan. Tashi has the highest fish fauna compare with the Tungkang and Nanfanao. Caelorinchus formorsanus , C.kishnouyei, C.multispinulosus and Ventrifossa rhipidodorsalis are the dominant species regarding to the total catch. As to the zoogeographical distribution, the species composition of grenadiers between north and south Taiwan are quite different. This result is quite consistent with the pattern obtained from coral reef and estuarine fishes. It may imply that the different fish fauna between northern and southern Taiwan can extend to the fishes which inhabit in deep waters. The thesis review the macrourids fauna of 9 areas of Indo-Pacific region. Taiwanese macrourids fauna are most similar to that of Japan and China. The global geographical distribution of macrourid species should be affected by the factors of degree of latitude, water temperature, ocean currents, land barrier, geographical distance, depth and substrata.
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