Abstract. A single specimen of Nessorhamphus ingolfianus (Schmidt, 1912) leptocephalus larva (NMMBLF16, 35.04 mm TL) was collected from Taiwan. Shallow ...
First offshore record of Nessorhamphus ingolfianus (Schmidt, 1912) (Derichthyidae) leptocephalus larva in the Taiwan Shallow Bank Leu, Ming-Yih1, Yumin Ju1, Chun-Ning Lin1 and Lee-Shing Fang2 1
National Museum of Marine Biology & Aquarium, Checheng, Pingtung 944, Taiwan, R.O.C.
2
Cheng Shiu University, No 840 Chengcing Rd., Kaohsiung County 833, Taiwan, R.O.C.
Abstract A single specimen of Nessorhamphus ingolfianus (Schmidt, 1912) leptocephalus larva (NMMBLF16, 35.04 mm TL) was collected from Taiwan Shallow Bank, Taiwan on 28 October 2005. This larva is identified as N. ingolfianus due to the presence of small melanophores above the eye, a simple gut without melanophores, a total of 154 myomeres, and the position of the last vertical blood vessel at the 78th myomere. Judging from the body length, appearance of the teeth and fins, and disposition of the anus, the present larva belongs to the pre-leptocephalus stage. The presence of this early larval stage in this area suggests that one of the spawning grounds of N. ingolfianus is near Taiwan Shallow Bank in autumn. Keywords: Nessorhamphus ingolfianus, Derichthyidae, Taiwan Shallow Bank, leptocephalus larva
Introduction
lives in the open ocean, with adults inhabiting depths of several hundred meters (Robins, 1989). N. ingolfianus is a bathypelagic species in the temperate and subtropical Atlantic, southwestern Indian, and southwest Pacific. Leptocephalus larvae of the species were caught in the Atlantic, Indian and Pacific Oceans (Karmovskaya, 1985). The present paper describes the first record of the offshore
The Derichthyid consists of 2 genera and 3 species, including Derichthys serpentines Gill 1884, Nessorhamphus ingolfianus (Schmidt, 1912) and Nessorhamphus danae Schmidt, 1931b. Derichthyids lack the strong morphological specializations of other midwater eels (Nemichthyidae, Serrivomeridae, and Saccopharyngiformes) and spend their
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distribution of N. ingolfianus leptocephalus in the Taiwan Shallow Bank.
an ichthyoplankton net on 28 October 2005 at a location several kilometers offshore of Taiwan Shallow Bank, Pescadores, Taiwan (119 ﾟ 44 E; 23 ﾟ 25 N) (Fig. 1). The specimen was fixed in 5%
Materials and Methods A single specimen was caught with
N
CHINA
East China Sea
Taiwan Strait Pescadores
Philippine Sea
South China Sea
E Fig. 1. Station location ( was collected.
Luzon Strait
★) from where the present specimen of Nessorhamphus ingolfianus
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Shallow Bank, Pescadores(119 ﾟ 44 E; 23 25 N), 28 October 2005, collected by Y. Ju. Diagnosis: The 35.04 mm N. ingolfianus larva is moderately elongate, with body depth 15% of its length; snout elongate, its length is equal to twice the eye diameter; teeth of the jaws are sharp; intestine long, greater than 86.7% of body length. Small melanophores are present near the upper margin of the orbit. Total myomeres 154, preanal myomeres 108. The last vertical blood vessel located at the 78th myomeres. Skeleton of dorsal fin poorly differentiated. Distribution: Eastern Atlantic: France to Morocco; off the Cape, South Africa. Also known from temperate and subtropical latitudes of the western Atlantic, southwestern Indian, and southwest Pacific.
formalin, transferred to 70% ethanol, and desposited at the National Museum of Marine Biology & Aquarium (NMMBA), Taiwan. Morphometric measurements and meristic counts followed Fahay (1983) and Mochioka (1988).
Results Leptocephalus ingolfianus Schmidt, 1912: 49. Nessorhamphus ingolfianus Schmidt, 1931a: 373; 1931b: 445, 487; Trewavas, 1932: 652; Beebe, 1935:29; Bruun, 1936: 10; Rees, 1964: 209; Nielsen, 1974: 53; Smith, 1979: 17; 1990: 194; Post & Tesch, 1982: 350; Karmovskaya, 1985:130; Paxton et al., 1989: 124; Robins, 1989: 427. Material examined: NMMBLF16 (Fig. 2), 1 specimen, 35.04 mm TL; off Taiwan
Fig. 2. Nessorhamphus ingolfianus (Schmidt, 1912) from Taiwan Shallow Bank (NMMBLF 16, 35.04 mm TL). Note posterior gut broken and omitted by plankton tow. 27
Discussion
January in the southwestern part of the Indian Ocean, mainly occurring in the 100-m layer. In the southcentral Pacific Ocean, larvae at different stages of development were found in October and November, mainly within the 0-150-m layer. N. ingolfianus has not been previously recorded in Taiwan, nor was it included in the latest list of Shen (1993). From the evidence of the collections of the present pre-leptocephalus larva, it was estimated that one of the spawning grounds of N. ingolfianus is near Taiwan Shallow Bank. According to oceanographical surveys conducted near the present area (Chern, 1982; Fan, 1982; Wang & Chern, 1989), the present specimen could have been transported by the Kuroshio Current if its migration is passive. Further studies on the spatial and temporal distribution of the leptocephali of N. ingolfianus throughout the region are needed to understand the early life history and recruitment mechanism of this species.
Nessorhamphus ingolfianus is a very rare, though widely distributed, deep-sea species. However, in the western Pacific it has never been reported. The present finding increases its range to include the entire Pacific. As we have already noted, N. ingolfianus, was described by Schmidt (1912) on the basis of leptocephali from the Azores. The position of the last vertical blood vessel at the 78th myomeres and presence of pigmented spots above the eye should be added to the diagnostic characters indicated by Schmidt. The latter character is of generic status and can serve as a good distinguishing feature of the leptocephali of Nessorhamphus from those of Derichthys and others (in particular, in leptocephali of genera belonging to family Serrivomeridae). Judging from the body length, appearance of the teeth and fins, and disposition of the anus, the present larva belongs to the pre-leptocephalus stage, the engyodonic stage (Leiby, 1979; Tabeta, 1988). N. ingolfianus is a Central Pacific species from 3 oceans (Karmovskaya, 1985). In the North Atlantic beyond the limits of central watermass, this species is found in the North Atlantic current up to 60ﾟN. Larvae at different developmental stages were found from April to December, which remain in the upper 100-m layer during day and night. Larvae at different developmental stages were found during
Acknowledgements The National Museum of Marine Biology and Aquarium (NMMBA) provided financial support for this research as part of NMMBA Project No. T9410010753. Special thanks to C.-J. Lin for his assistance in the photographs.
References Beebe, W. 1935. Deepsea fishes of the Bermuda oceanographic expedition. I. Fam. Derichthyidae. 1. Fam. Nessorhamphidae.
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an oceanic eel recorded in Canadian continental waters. Journal of the Fisheries Research Board of Canada, 21: 209-211. Robins, C.H. 1989. Family Derichthyidae. In E.B. Bohlke (Ed). Fishes of the Western North Atlantic. Part 9 Volume 1: Orders Anguilliformes and Saccopharyngiformes. Sears Foundation for Marine Research, Yale University. pp. 420-431. Schmidt, E.J. 1912. Contributions to the biology of some North Atlantic species of eels. Videnskabelige Meddelelser fra Dansk Naturhistorik Forening Köbenhavn, 64: 39-51. Schmidt, E.J. 1931a. Nessorhamphus , a new cosmopolitan genus of oceanic eels. Videnskabelige Meddelelser fra Dansk Naturhistorik Forening Kjøbenhavn, 90: 371-375. Schmidt, J. 1931b. Oceanographic expedition of the Dana, 1928-1930. Nature (London), 127: 444-446, 487-490. Shen, S.C., S.C. Lee, K.T. Shao, H.K. Mok, C.T. Chen & C.H. Chen. 1993. Fishes of Taiwan. Department of Zoology, National Taiwan University, Taipei. 960 pp. Smith, D.G. 1979. Guide to the leptocephali (Elopiformes, Anguilliformes). NOAA Technical report, NMFS circular 424, 1-39. Smith, D.G. 1990. Derichthyidae. In J.C. Quero, J.C. Hureau, C. Karrer, A. Post & L. Saldanha (Eds). Check-list of the fishes of the eastern tropical Atlantic (CLOFETA). Vol. 1. JNICT, Lisbon; SEI, Paris; and UNESCO, Paris. pp. 193-194. Tabeta, O. 1988. Leptocephalus larvae. In M. Okiyama (Ed). An Atlas of the Early Life Stage Fishes in Japan. Tokai University Press, Tokyo. p. 15. Trewavas, E. 1932. A contribution to the classification of the fishes of the order Apodes, based on the osteology of some rare eels. Proceedings of the Zoological Society of London, 2: 639-659. Wang, J. & C.S. Chern. 1989. On cold water intrusions in the eastern Taiwan Strait during the cold season. Acta Oceanographica Taiwanica, 22: 43-67.
Zoologica, New York, 20: 25-51. Bruun, A.F. 1936. Sur la distribution, de quelques poisons océaniques d’après les expeditions danoises. Bulletin de L'institut Oceanographique Monaco, 700: 1-16. Chern, C.S. 1982. A preliminary study on the response of Taiwan Strait to winter monsoon. Acta Oceanographica Taiwanica, 13: 124-139. Fahay, M.P. 1983. Guide to the early stages of marine fishes occurring in the western North Atlantic Ocean, Cape Hatteras to the southern Scotian Shelf. Journal of Northwest Atlantic Fishery Science, 4: 1-423. Fan, K.L. 1982. A study of water masses in Taiwan Strait. Acta Oceanographica Taiwanica, 13: 140-153. Gill, T.N. 1884. Three new families of fishes added to the deep-sea fauna in a year. The American Naturalist, 18: 433. Karmovskaya, E. 1985. Mesopelagic eels of Family Derichthyidae (Anguilliformes). Journal of Ichthyology, 25: 119-134. Leiby, M.M. 1979. Leptocephalus larvae of the eel family Ophichthyidae. I. Ophichthus gomesi Castelnau. Bulletin of Marine Science, 29: 329-343. Mochioka, N. 1988. Derichthyidae. In M. Okiyama (Ed). An Atlas of the Early Life Stage Fishes in Japan. Tokai University Press, Tokyo. p. 62. Nielsen, J.G. 1974. Fish types in the Zoological Museum of Copenhagen. 115 pp. Paxton, J.R., D.F. Hoese, G.R. Allen & J.E. Hanley. 1989. Zoological Catalogue of Australia. Volume 7: Pisces. Petromyzontidae to Carangidae. Australian Government Publishing Service, Canberra. 665 pp. Post, A. & F.W. Tesch. 1982. Midwater trawl catches of adolescent and adult anguilliform fishes during the Sargasso Sea Eel Expedition. Helgolander Meeresuntersuch., 35: 341-356. Rees, E.I.S. 1964. Nessorhamphus ingolfianus,
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台灣淺灘新記錄之鴨頸鰻 Nessorhamphus ingolfianus (Schmidt, 1912)(頸鰻科)狹首型仔魚 呂明毅 朱育民 林君寧 方力行 1
1
1
1
2
國立海洋生物博物館 正修科技大學 2
摘 要 2005年10月28日，在澎湖群島的西南方海域-台灣淺灘採集到1尾狹首型仔魚標本 (館藏編號：NMMBLF16)。此尾仔魚體全長35.04 mm，總肌節數為154，最終垂直血 管位於第78肌節處，消化道呈直線狀，小黑色素胞僅分布於眼之下方，由上述特徵 可以鑑定為鴨頸鰻
Nessorhamphus ingolfianus
(Schmidt, 1912)，屬於台灣新記錄之科、
屬、種魚類。此外，由體長、牙齒及鰭膜發育、肛門在肌節之位置，推測其屬於狹 首型前期仔魚。根據這尾仔魚的出現，可以推斷鴨頸鰻的產卵場也許位於台灣淺灘 附近海域，且產卵期在秋天。
關鍵詞：鴨頸鰻，頸鰻科，台灣淺灘，狹首型仔魚。
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