Family Mastacembelidae)
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Iran. J. Ichthyol. (March 2015), 2(1): 1–12 Received: January 01, 2015 © 2015 Iranian Society of Ichthyology Accepted: February 29, 2015 P-ISSN: 2383-1561; E-ISSN: 2383-0964 doi: http://www.ichthyol.ir Review Article Review of the Spiny Eels of Iran (Family Mastacembelidae) Brian W. COAD Canadian Museum of Nature, Ottawa, Ontario, K1P 6P4 Canada. Email: [email protected] Abstract: The systematics, morphology, distribution, biology, economic importance and conservation of the spiny eel (Mastacembelus mastacembelus) of Iran are described, the species is illustrated, and a bibliography on this fish is provided. The single species is distributed in southern Iranian basins, including Karkheh, Karun, Jarrahi and Helleh river basins, mostly part of the Tigris River and Persian Gulf basins. Keywords: Biology, Morphology, Systematics, Distribution, Mastacembelus. Introduction freshwater riverine family with an Old World The freshwater ichthyofauna of Iran comprises a distribution throughout tropical Africa and eastwards diverse set of families and species. These form to Korea and Malaysia in Asia although the majority important elements of the aquatic ecosystem and a of species occur in Africa. The distribution mapped number of species are of commercial or other by Berra (2001) extends too far into central Iran. significance. The literature on these fishes is widely Boulenger (1912), Sufi (1957), Travers (1984a, scattered, both in time and place. Summaries of the 1984b) and Yazdani (1990) review the spiny eels. morphology and biology of these species were given Their biodiversity and zoogeography in relation to in a website (www.briancoad.com) which is updated other Iranian fishes is summarised in and Coad here, while the relevant section of that website is now (1987, 1998) and Coad & Abdoli (1996) and their closed down. familial and generic relationships with neighboring The swamp eels (Order Synbranchiformes) basins in other countries in Coad (1996). Maximum comprise three families (Synbranchidae, length is less than 1.0m. Chaudhuriidae and Mastacembelidae), 15 genera and The family is characterised by a very elongate, about 100 species found in fresh waters, although compressed or sub-cylindrical body, minute cycloid three species are primarily Archivemarine. The spiny eels scales of or body SID naked, a non-protractile mouth, gill (Mastacembelidae) are found in freshwaters of opening a slit, an elongate snout with a sensitive tip tropical Africa, the Middle East and northern India flanked by tubular anterior nostrils, the posterior through Thailand to Korea (Nelson 2006) and nostrils are hence far to the rear, long dorsal and anal comprise 84 species (Eschmeyer & Fong 2015), soft fins (30-131 rays), dorsal soft fin preceded by among which, Iran has only one species. usually numerous isolated spines (9-42), anal fin preceded by 2-3 spines, pectoral fin present with 12- Family Mastacembelidae 27 rays but pelvic fin absent, caudal fin short and Mastacembelids, the spiny eel or spinyback family confluent with the dorsal and anal fins or only (Teleostei: Synbranchiformes) is a predominately separated narrowly, 60-110 vertebrae, no 1 www.SID.ir Iranian Journal of Ichthyology (March 2015), 2(1): 1-12 Fig.1. Line drawing of Mastacembelus mastacembelus by C. D. Douglas. Fig.2. Detail of head of Mastacembelus mastacembelus by C. D. Douglas. pseudobranchiae, 2 pyloric caeca, and gas bladder Mastacacemblus. present. The genus is characterised by a moderate to large Some species are food fishes and they regularly size, an elongate and compressed body, inferior appear in the aquarium trade as they are brightly mouth with a narrow cleft, small eyes, the absence of coloured with distinctive patterns. They may burrow eye spots on the soft dorsal fin, the absence of in mud and even survive some drying in ponds striations under the snout, 6 branchiostegal rays, through their air-breathing ability. Their eel-like preopercle spiny or not at its posteroventral corner, shape is reflected in a wriggling behaviour when preorbital spine present, scales minute and cycloid, handled and some are known to move backwards to elongate gas bladder, lateral line present, minute jaw impale the hand with their dorsal spines. They are and palate teeth, and a rounded caudal fin. found at high altitudes as wellArchive as in lowlands, in both of SID still and running waters, often in rocky crevices or in Mastacembelus mastacembelus vegetation near banks, and they emerge particularly (Banks & Solander in Russell, 1794) at night to feed on prey. The rostral appendage is used (Figs. 1-5) to detect the prey by touch and the prey is rapidly Common names: Marmahi (= snake fish), marmahi- inhaled. ye khardar (= snake fish with spines or spiny snakefish), marmahi shakhdar. [salbouh abu-el-sian, Genus Mastacembelus Scopoli, 1777 salbu-al-sayan, saebouh abou siyan (= salbūħ-al- This spiny eel genus is found from the Levant to siyān and salbūħ abū-l-siyān meaning mud worm or Southeast Asia. There is one species in Southwest dwelling in mud worm, after Mikaili & Shayegh Asia. Heckel (1847) misspells the genus name (2011)); abu salmabah; simack, englisi or englese at 2 www.SID.ir Coad-Review of the Spiny Eels of Iran Fig.3. Ophidium Mastacembelus from Russell (1794), scan from original in possession of B.W. Coad. Fig.4. Mastacembelus mastcaembelus from Dalaki River, Helleh, 25 December 2011, courtesy of H.R. Esmaeili. Fig.5. Mastacembelus mastcaembelus from Adıyaman, Turkey, courtesy of J. Freyhof. Aleppo; hanklees in Syria (FAO 2014), all in Arabic; Mastacembelus aleppensis Günther, 1861 is an marmaritch or marmarij at Mosul (perhaps from the unjustified emendation of haleppensis (Eschmeyer et Persian marmari (= marble) in relation to colour al. 1996). Wheeler (1956) and Sufi (1957) discuss the pattern, after Mikaili Archive& Shayegh (2011)); names of of this speciesSID more fully. Mesopotamian spiny eel, Euphrates spiny eel]. Three syntypes of Ophidium Mastacembelus Systematics: Ophidium Mastacembelus was from "Aleppo" are in the Natural History Museum, originally described from "Aleppo" and from the London under BM(NH) 1955.6.25:4-6, measuring "River Kowick" (= Quwayq) in the book by Russell 289.5-544.0mm standard length. (1794). Çakmak (2008) and Çakmak & Alp (2010) Ophidium Simack Walbaum, 1792 (non- found morphological differences between river and binomial), Rhynchobdella haleppensis Bloch and reservoir populations in Turkey, but none for meristic Schneider, 1801 and Mastacembelus syriacus and molecular traits. Some differences appear to be Gronow in Gray, 1854 are synonyms. associated with habitat type, a thicker and longer 3 www.SID.ir Iranian Journal of Ichthyology (March 2015), 2(1): 1-12 caudal peduncle in river populations may enhance Colour: The body is blotched and barred, often swimming ability in faster water and longer lower forming a reticulate pattern, or a series of mid-flank jaws in river fish could be a feeding adaptation, for blotches most evident posteriorly and sometimes example. running together as a stripe anteriorly. Flank blotches Key characters: The eel-like body with 30-35 short, may form up to 18 bars running from the dorsal to the sharp dorsal spines, long soft dorsal and anal fins and anal fin across the flank. The back is blackish to the unique flexible snout flanked by tubular nostrils brown, olive, greyish or blue-grey, the lower flank is distinguish this species from all other Iranian fishes. spotted yellow or is yellow overall and the belly is Morphology: The mouth gape extends back as far as white to yellowish. A series of about 20-24 black to the anterior eye margin or somewhat forward of this blackish-brown, oval spots ringed with a lighter point. The posterior nostril is slit-like. The structure brown follow a dark, broad but irregular stripe on the and function of the olfactory apparatus and fleshy head and anterior back in the mid-line. Dorsal, anal tentacle is described by Jasim (1996). The structure and caudal fins are yellowish with the dorsal and of the elongated eye, typical of streamlined forms, caudal fins finely barred, and the anal fin continuing has been described by Jasim (1998) based on Iraqi the pattern on the adjacent body. The anal fin may be specimens. The regular, mosaic pattern of the retina almost immaculate. The soft dorsal fin may have is associated with fishes that search for their food and vermiculations rather than bars. The pectoral fins are the double cone structure may be associated with yellowish and are finely barred. The peritoneum is detection of moving prey. brownish, with numerous fine melanophores. Small Soft dorsal rays 68-90, soft anal rays 70-90 after fish (about 7.7cm total length) can be an almost 3 spines, pectoral rays 18-24 and total vertebrae 85- uniform grey-brown to brown-green, with yellowish 88. The penultimate spine in the dorsal fin is the brown on the fins and the tail region, and fin spots are longest and the central anal spine is the longest. dark to absent. There is a thin bar extending vertically Iranian specimens had 30(4), 31(6), 32(7) or 33(4) down or obliquely back from the eye. dorsal fin spines, 19(5), 20(3), 22(1) or 23(1) pectoral Size: Reaches 85.0cm total length and 1.1kg (Oymak fin branched rays, and total vertebrae 86(1) or 87(1). et al. 2009), and probably larger to almost 1.0m. Kara et al. (2014) summarise morphometric and Distribution: Found in the Quwayq, Orontes, and meristic data for some Turkish populations. The Tigris-Euphrates and adjacent basins (Coad 2010; diploid chromosome number is 2n=48, arms number Esmaeili et al. 2010). In Iran it is recorded from the NF=88 and there are 11 metacentric, 9 Tigris River basin including the Shadegan Wetland, submetacentric and 4 subtelocentric chromosome lakes Zaribar and Marivan, Sarab Nilofar, the Gav pairs (Esmaeili et al.