西太平洋地區鮟鱇科、棘茄魚科及單棘躄魚科（鮟鱇目）之分子系統分類

Abstract

鮟鱇科 (Lophiidae)、棘茄魚科 (Ogcocephalidae)、單棘躄魚科 (Chaunacidae)，同屬鮟鱇目 (Lophiiformes)，其科內物種大部分為深海底棲性。過去由於此三科內物種間形態特徵差異不大，使某些物種分類問題懸而未解。雖然前人以形態特徵對此三科內物種分別提出種群假說，然而這些假說皆沒有進一步以其它研究方法驗證。本研究利用分子系統分類方法，對分佈於西太平洋地區鮟鱇科、棘茄魚科及單棘躄魚科的物種標本進行親緣關係之推衍，以達成下列目的：(1) 檢視西太平洋地區此三科內分析物種之有效性及其分類地位；(2) 校正西太平洋地區此三科魚類之物種多樣性及地理分布；(3) 檢驗前人根據形態特徵對此三科建構之種群假說是否成立；(4) 檢驗此三科物種與其他鮟鱇目類群（躄魚亞目及角鮟鱇亞目）間的親緣關係假說。研究結果顯示，鮟鱇亞目（鮟鱇科）為鮟鱇目最早分化類群，單棘躄魚亞目（單棘躄魚科）與角鮟鱇亞目形成姊妹群，但其餘兩類群（棘茄魚亞目及躄魚亞目）親緣關係位置無法確定。鮟鱇科內四個屬皆獨立形成單系群 (monophyletic group)，但屬間親緣關係未解決。在Lophiodes屬內則形成四個演化系群，其中Lophiodes mutilus並非為單系群，種內至少有兩個隱蔽種。在單棘躄魚科中， Chaunax屬物種為單系群，其屬內物種的分類地位已進一步釐清，並發現五個可能的新種。棘茄魚科中，共發現十個可能的新種；部分屬間親緣關係獲得解決，然而Coelophrys、Halieutopsis、Malthopsis及Solocisquama屬未形成單系群，其中Coelophrys屬的物種應被歸到Halieutopsis屬的基因系群內；而Malthopsis mitrigera及Solocisquama erythrina並未與其它同屬物種形成單系群。此外，Halieutaea屬內形成五個演化系群，何博士待發表新種 Halieutaea n. sp. 不屬於Halieutopsis屬其它已知的四個種群。Halicmetus屬內形成兩個演化系群，但屬內多數物種之分類地位仍待進一步解決。

The families Lophiidae, Ogcocephalidae, and Chaunacidae belong to the order Lophiiformes. Most of the species in these three families are deep-sea benthic dwellers. Because few informative morphological characters useful for species delineation and for inferring intra-familiar phylogeny, some taxonomic problems persist. Although the species-group hypotheses within these families have been proposed previously using morphological characters, none of them were tested with other methods. In this study, molecular systematic approach is employed. I infer species phylogeny for the families Lophiidae, Ogcocephalidae, and Chaunacidae from the samples collected in the western Pacific Ocean. Our main objectives are: (1) to evaluate the validity of the species occurring in the western Pacific Ocean of these three families; (2) to revise the species diversity and the distribution pattern of these three families in the western Pacific Ocean; (3) to test the species-group hypotheses previously proposed based on morphology; (4) to test the previous phylogenetic hypotheses of the relationships among these three families and their relationships with other suborders (Antennarioidei and Ceratioidei). From our results, the Lophioidei (Lophiidae) is the basal-most group within the Lophiiformes, and the Chaunacoidei (Chaunacidae) form a sister-group to the Ceratioidei. However, the phylogenetic positions of the other two suborders (Antennarioidei and Ogcocephaloidei) are not confidently resolved. In Lophiidae, four genera from the Lophiidae are monophyletic respectively, but their inter-relationships remain unsolved. Four major lineages in the genus Lophiodes are identified; Lophiodes mutilus is not monophyletic with at least two cryptic species within it. In Chaunacidae, the samples from the genus Chaunax form monophyletic group. The taxonomy status of the species within the Chaunax is further clarified; five potential new species are recognized. In Ogcocephalidae, ten potential new species are recognized, and intergeneric relationships are partially resolved. The genera Coelophrys, Halieutopsis, Malthopsis and Solocisquama do not appear to be monophyletic; Malthopsis mitrigera and Solocisquama erythrina are separated lineages from other Malthopsis and Solocisquama species, and the Coelophrys is nested within the Halieutopsis. In addition, five lineages are found in the Halieutaea; an unpublished species by Dr. Ho, Halieutaea n. sp., forms an additional group to four existing species-groups. Two clades are found in the Halicmetus; however, taxonomic status for the species within the genus awaits for further clarifications.