Bijdragen tol de Dierkunde, 53 (2): 227-232 — 1983 Saurenchelys halimyon, a new species of nettastomid eel, with comments on Saurenchelys cancrivora Peters, 1864, and a preliminary list of larval and metamorphosed Anguilliformes caught in the mid North Atlantic by W.L. van Utrecht Institute of Taxonomie Zoology (Zoologisch Museum), University of Amsterdam, P.O. Box 20125, 1000 HC Amsterdam, The Netherlands Summary to Van der Spoel (1981). All animals recorded here are in the RMT 8 net. are is caught They A new species of nettastomid eel, Saurenchelys halimyon, in the collections of the described and figured. The leptocephalus of Saurenchelys kept Zoölogisch Amsterdam cancrivora Peters, 1864, is redescribed; noresemblance was Museum, (ZMA). found to the leptocephalus of Facciolella (Fac- nettastomid physonema A new species of eel, Saurenchelys ciola, 1914) as was supposed by Blache (1977). Fourteen was It is described and halimyon, caught. figured species are listed of larval and metamorphosed here, after comparison with all available data of Anguilliformes caught in April 1980 in the mid North the related 1864. Atlantic. closely S. cancrivora Peters, Résumé Saurenchelys halimyon nov. spec. (Figs. 1-2) Une espèce nouvelle d’Anguilles de la famille des Net- décrite tastomatidae, est et figurée. Material. — total ZMA Saurenchelys halimyon, Holotype, length (TL)183.5 mm, La larve de S. cancrivora leptocéphale Peters, 1864, est 118.791, mid Atlantic Ocean, type-locality 35°14.4'N il de le redécrite; n’y a pas ressemblance avec leptocéphale 31°31.6'W, station 20, haul 12, caught between de Facciolella l’avait physonema (Facciola, 1914), comme 04.21-05.22 h at a depth between 40 and 110 m, supposé Blache (1977). On donne une liste de 14 espèces 26-IV-1980. d’Anguilliformes (larves ou exemplaires métamorphosés) capturées en avril 1980 dans la partie centrale de l’Atlanti- — The shows all Diagnosis. new species Nord. que characteristics of the Nettastomatidae, it has features in with many common Saurenchelys can- INTRODUCTION crivora Peters, 1864, but it is much longer and has number of a greater myomeres. During the Amsterdam Mid North Atlantic * Plankton Expedition with the Dutch Royal Description. — Body in fresh condition nearly research vessel "H. M. from About Navy Tydeman", completely transparent. 273 myomeres, 11 2 taken the caudal in tail April up to May 1980, samples were extreme ones the pointed are with the combined Midwater difficult to 73 Rectangular discern; preanal myomeres. Trawl 1 at between Distance from of 59.5 (RMT + 8) depths varying tip snout to anus: mm; 30 and 1200 These taken of half m m. samples were height body at of total length: 7.8 mm; between 55°N and 24°N, along the 30°W length of head, from tip of snout to posterior station of longitude. For a complete list including end occiput: 11.04 mm; length of protruding technical and referred of first hydrological data, one is part snout, two teeth inclusive: 0.56 of nasal 3.52 mm; length capsule: mm (anterior * AMNAPE, Project 101 A, Report no. 13, supported by and posterior nostril included). Distance be- a grant of the Netherlands Ministry of Education and tween posterior nostril and anterior of Sciences, N.Z.R. (Report no. 12 appeared in Beaufortia, margin 33 1.36 (6): 73-96). eye: mm. 228 W. L. VAN UTRECHT - A NEW NETTASTOMID EEL end of the nasal is close smaller the medulla The anterior capsule spot more caudally on to the tip of the snout, at a shorter distance than oblongata. in S. of cancrivora. In the present specimen the Along the ventral margin the body, brown is in a the intestine snout bulging, ending pronounced tip, pigment spots are present on up to from the of the the clearly separated rest snout (fig. anus. Deeper pigment spots are present each the chorda. 10th to 1). The nasal capsules are separated from along They are at every 15th other. anterior nostril is The slightly tubular; myomere. the nostril is oval Intestine with the anterior posterior an pore. two dilatations, Length of upper jaw: 6.16 mm; length of one between myomeres 10 and 14, the posterior Five between lower jaw: 5.36 mm. pores are present one myomeres 69 and 72. the dorsal of the above the The fins small and along margin snout pectoral are pointed nasal capsule, and four along the margin of the (triangular). The caudal fin is pointed, contain- A of five is six three each The dorsal upper jaw. row pores present along ing rays, on hypural. fin arises far from the the lower jaw (fig. 1). not occiput, at myomere where the first fine soft visible. The 14, rays are anal fin arises immediately beyond the anus with stiff relatively long rays. — The is derived Etymology. specific name from the Greek ÔcXtç meaning "in abundance", and in allusion (xucjv meaning "muscle", to 1. Head of Fig. Saurenchelys halimyonn. sp. (ZMA 118.791). the numerous myomeres. Saurenchelys cancrivora Peters, 1864 (Figs. 3-4) Refs.: Peters, 1864: 397-399; Grassi, 1913: 162, pl. IX figs. 26-44. Fig. 2. Tip of snout and lower jaw of Saurenchelys halimyon — One TL ZMA Material. specimen, 104.0 mm, n. sp. (ZMA 118.791). 118.790, mid Atlantic Ocean, 31°58.2'N 29° 54.0'W, station 22, haul 7, caught between 00.19-02.19 h at a The first teeth in the jaw are only between upper depth 90 and 200 m, 28TV-1980. slightly bent and point nearly straight forward, the snout is straight (fig. 2). This is different Description. — Body in fresh condition nearly S. Number of compared to cancrivora, which species has completely transparent. myomeres snout and first teeth bent downward. The teeth 247, of which 68 preanal. Distance from tip of small rather uniform 34.9 of half are relatively and in shape snout to anus: mm. Height body at and for the frontal which of total 3.2 of head from size, except teeth, are length: mm. Length tip longer. Dental formula: of snout, first teeth included, to posterior end of 2 - 20 occiput: 7.8 mm. Length of snout from tip to 1 - 15 ' of nasal 1.76 This anterior border capsule: mm. 1.52 in with is S. hali- Eye round, mm diameter, considerably longer as compared to the dorsal of its described above. silvery pigmented iris, quart myon covered with black nasal margin a pigmented cap. Length of capsule, including oval Brown Distance between pigment present at basis of tip of snout posterior nostril: 1.92 mm. basis of "nose". Two of nasal and along bulging deep pig- posterior margin capsule eye: 0.44 in the of the The is whereas the ment spots are present area brain, mm. snout not bulging, tip anterior the and and the first teeth bent downward a larger spot on cerebellum, a two are (figs. - 229 BIJDRAGEN TOT DE DIERKUNDE, 53 (2) 1983 The nasal close to each other fine soft The anal fin is 3, 4). capsules are rays are present. sup- another in the midline which somewhat and partly touching one ported by fine soft rays are and in the of the tail of the last of the snout. The anterior posterior nostrils more developed part oval of which the first is within 20 The tail is with six are pores, one myomeres. pointed rays, three each The median the contour of the nasal capsule. on hypural. two rays are of Length of upper jaw: 4.64 mm; length longest. The animal fits in with lower jaw: 3.5 mm. No pores are present on present completely Grassi snout and lower jaw. the descriptions and figures given by The small and rather uniform in with those Blache teeth are (1913), however, not given by size. Dental formula: (1977). 2-14. 1-15 Remarks. — Within the family Net- The confusion exists about Diameter of the round eyes: 1.04 mm. tastomatidae some iris is covered by brown chromatophores. The Saurenchelys cancrivora. Peters has given the first in 1864. The head is unpigmented, except for two small description of this species type- the blackish brown pigment spots on specimen, in bad condition (Grassi, 1913) was cerebellum and the medulla oblongata. On the deposited in the Berlin Museum. The probable is small brown whereas four Peters the vomer a light spot, type-locality given by (1864) was black in around the Mediterranean the Atlantic Ocean. Accord- spots are arranged a square or heart. ing to Blache et al. (1973) the type-specimen is lost. extensive Grassi (1913, 1914) gives an description of the leptocephalus of this species animals and its development, based on caught in the Strait of Messina. D'Ancona (1931) repeats this description. Sanzo (1938) gives a of the and description of the development eggs Fig. 3. Head of Saurenchelys cancrivora Peters, 1864 (ZMA early development of the leptocephalus of S. 118.790). of cancrivora, based on material from the Strait Messina and the Gulfof Napels. These descrip- with each other with tions and figures agree the features of S. cancrivora. respect to typical The most characteristic features of this the 238-246 of which species are myomeres, 4. of and lower of cancrivora Fig. Tip snout jaw Saurenchelys 61-66 preanal, the difference in length between 1864 (ZMA 118.790). Peters, lower the of the the upper and jaw, bent form tip of the snout, which is accentuated by the Along the ventral margin of the body, small downward bent form of the first two teeth, and the intestine. the nasal which touch each other in the pigment spots are present on capsules There the middle and little above the are no deep pigment spots along are bulging a con- chorda.