Dysomma dolichosomatum Karrer 1983

• Main Authors: Ho, Hsuan-Ching, Smith, David G., Tighe, Kenneth A.
• Format: Text
• Language: unknown
• Published: Zenodo 2015
• Subjects: Biodiversity; Taxonomy; Animalia; Arthropoda; Insecta; Coleoptera; Curculionidae; Dysomma; Dysomma dolichosomatum; Pacific; North Atlantic
• Online Access: https://dx.doi.org/10.5281/zenodo.5295836; https://zenodo.org/record/5295836

Dysomma dolichosomatum Karrer, 1983 Figs. 4 A–B; Table 1 Dysomma dolichosomatum Karrer, 1983: 93 (type locality: Madagascar, 22 ° 25 'S, 43 °04.5'E, 550–555 m). Robins & Robins, 1989: 249. Chen & Mok, 2001: 79. Specimens examined. Collected from Fong-gang, SW Taiwan: NMMB-P 2861 (1 spec., 242 mm TL), 8 Nov. 2001. Collected from Dong-gang fishing port, SW Taiwan: NMMB-P 9098 (1, dry), 13 Jun. 2008. NMMB-P 9241 (1, 349), 18 Sep. 2008. NMMB-P 11121 (6, 209 – 312), 16 Jul. 2009. NMMB-P 11130 (2, 231 – 269), 13 Sep. 2010. NMMB-P 12066 (1, 336), 28, Jan. 2011. NMMB-P 13794 (1, 197), 21 Jul. 2011. NMMB-P 14189 (4, 166 – 301), 20 Oct. 2011. NMMB-P 15568 (2 of 4, 218 – 294), 25 Oct. 2011. NMMB-P 16134 (1, 189), 9 Feb. 2012. NMMB- P 16404 (4, 264 – 320), 28 Jan. 2012. NMMB-P 16422 (1, 357), 21 Feb. 2012. NMMB-P 17820 (1, 357), 2 Nov. 2012. NMMB-P 17881 (1, 263), 25 Jan. 2012. NMMB-P 18083 (1, 336), 7 Sep. 2012. NMMB-P 21733 (2, 215 – 221), 18 Feb. 2011. NMMB-P 21799 (1, 227), 7 Nov. 2013. NMMB-P 21928 (1, 343), 1 Nov. 2014. NMMB-P 22126 (1, 242), 12 Dec. 2013. USNM 270682 (2, 172 – 187), 23 Nov. 1969. USNM 398567 (1, 317), 10 Nov. 2009. USNM 401019 (1, 197), 26 Feb. 2011. USNM 401036 (1, 345), 8 Nov. 2009. Other localities. Madagascar: MNHN 1979 -0004, holotype, 22 ° 25 ' 1.2 "S, 43 ° 4 ' 4.8 "E, 550–555 m, 27 Nov. 1973. Philippines: MNHN 1978 -0717, paratype, 14 ° 1 ' 1.2 "N, 120 ° 22 ' 1.2 "E, 223 m, 21 Mar. 1976. Solomon Islands: MNHN 2006 -0734 (1, 203), 8 ° 24 ' 28.8 "S, 159 ° 28 ' 22.8 "E, 105–897 m, 24 Oct. 2004. Diagnosis. No pectoral fin; dorsal-fin origin about 0.8–1 HL behind gill opening, predorsal length 16.5–19.1 % TL; anus posterior, about 1.5 time of HL behind gill opening, preanal length 23.3–28.6 % TL; trunk long, trunk length 14.3–17.7 % TL; two intermaxillary teeth; 2 irregular rows of small blunt teeth on upper jaw; 2 or 3 (mainly 3) compound teeth on vomer; single row of 4 or 5 small compound teeth followed by 1 or 2 irregular rows of small blunt teeth on lower jaw; short cirri on surfaces of chin and jaws; head pores: IO 4, SO 3, M 6 (1 with 7), POP 1, AD 1, F 0, ST 0; lateral-line pores large, prepectoral 5 or 6, total 9–11, the last at slightly beyond the gill opening posteriorly; MVF 18-27 - 153, total vertebrae 146–156. Body light pinkish to light grayish dorsally when fresh with a black margin at posterior portion of anal fin; light brownish to grayish when preserved. Distribution. Indo-west Pacific off Madagascar, Taiwan, Philippines, and Solomon Islands at depth 105– 897 m. Remarks. This species is common in the by-catch in Taiwan. It is usually collected by midwater trawlers together with many mesopelagic fishes, which would indicate pelagic living. However, many specimens are also found to feed on polychelids, a demersal shrimp family. Dysomma dolichosomatum is the only species found to possess one preopercular pore and a very short lateral line, with only 9–11 pores, among all Taiwanese species. It is similar to D. brevirostre , D. muciparus and D. tridens in lacking a pectoral fin. It differs from D. brevirostre by having tiny papillae on the head and snout (vs. large papillae and ridges) and total vertebrae 146–156 (vs. 195–205 in Robins & Robins, 1989); from D. muciparus by having trunk 1.4–1.9 times in head length (vs. less than 1 time in head length) and 146–156 total vertebrae (vs. 153–157); and from D. tridens by having 2 intermaxillary teeth (vs. three large compressed teeth) and by having 146–156 total vertebrae (vs. 175). Our specimens have a broader range of total vertebrae (146–156) compared to 151–152 reported for the types by Karrer (1983). One 312 mm specimen out of NMMB-P 11121 had a relatively long predorsal measurement (23.4 % of TL) and high predorsal vertebral count (25 vertebrae). While it is possible that this specimen may represent a different species, the close correspondence of all other counts and measurements with the other specimens of D. dolichosomatum from Taiwan indicates that it is probably a specimen with an aberrant dorsal origin. : Published as part of Ho, Hsuan-Ching, Smith, David G. & Tighe, Kenneth A., 2015, Review of the arrowtooth eel genera Dysomma and Dysommina in Taiwan, with the description of a new species (Anguilliformes: Synaphobranchidae: Ilyophinae), pp. 86-104 in Zootaxa 4060 (1) on pages 93-94, DOI: 10.11646/zootaxa.4060.1.12, http://zenodo.org/record/237500 : {"references": ["Karrer, C. (1983) Anguilliformes du Canal de Mozambique (Pisces, Teleostei). Faune Tropicale, 23, 1 - 116.", "Robins, C. H. & Robins, C. R. (1989) Family Synaphobranchidae. In: Bohlke, E. B. (Ed.), Fishes of the Western North Atlantic. Memoirs of the Sears Foundation for Marine Research, 1 (Part 9), 207 - 253.", "Chen, Y. - Y. & Mok, H. - K. (2001) A new synaphobranchid eel, Dysomma longirostrum (Anguilliformes: Synaphobranchidae), from the northeastern coast of Taiwan. Zoological Studies, 40 (2), 79 - 83."]}