Narcinidae
Eyespot electric ray ( Diplobatis ommata )
The rays of the Narcinidae family ( Gr. " narke " = paralysis) are close relatives of the electric ray ( Torpedinidae ). The nearly 30 species are rather small animals 18-76 centimeters in length. Most species remain below a length of half a meter.
Features
They are disc- shaped, sometimes elongated, have a shark-like provided with a tail fin tail and 0-2 dorsal fins. The body is naked, and neither on the top nor on the bottom with thorns or placoid scales covered. The head is broad and flattened, the rostrum ends rounded or obtuse, with rounded corners. The eyes on the top of the head are located just before the injection holes or almost in between. The mouth but has no significant labial pits at the corners of his mouth. The nostrils are located just before dam mouth at a distance which is much smaller than the diameter of the nares. They are connected by wide Nasalgruben. The anterior nasal flaps are short, laterally expanded and fused together. They overlap the mouth easily. On the bottom are on each side five small gill openings just before the middle of the pectoral fin base. Reuse gill rays are missing. The mouth but has no significant labial pits at the corners of his mouth. The nostrils are located just before dam mouth at a distance which is much smaller than the diameter of the nares. They are connected by wide Nasalgruben. The anterior nasal flaps are short, laterally expanded and fused together. They overlap the mouth easily. The tail can be as long or longer than the body plate. The tail is only slightly flattened and has usually via lateral keels. A tail sting is missing. The caudal fin is about as large as ventral fins, can be symmetrical or asymmetrical.
As the actual electric ray (Torpedo ) that they have two kidney-shaped electric organs on the head and front body, consisting of muscle and converted by which they can paralyze prey fish by electrical discharges.
The Narcinidae are whitish, yellowish, gray-green or brown on the top. More or less pronounced Fleckungen can be present or absent. The underside is whitish, the black of the deep-sea forms.
Dissemination
The Narcinidae live in the Atlantic and Indo-Pacific, usually in shallower areas, on sandy coastal areas, estuaries and on the upper parts of the shelf. Benthobatis moresbyi lives at depths of 780-1070 meters.
Way of life
They are slow-moving bottom - dwellers that are often found on soft mud or sand. All species are not known to ovoviviparous. They feed on invertebrates and small fish, which they take from the ground. The strong protaktile ( vorstreckbare ) mouth of the fish can be formed into a tube and the prey are sucked out of the ground. Man caught Narcinidae may emit a moderate electric shock if your body disc is touched.
System
There are four genera and nearly 30 species:
- Genus Benthobatis Benthobatis kreffti Rincon, Stehmann & Vooren, 2001.
- Benthobatis marcida Bean & Weed, 1909.
- Benthobatis moresbyi Alcock, 1898.
- Diplobatis colombiensis Fechhelm & McEachran, 1984.
- Diplobatis guamachensis Martín Salazar, 1957.
- Eyespot electric ray ( Diplobatis ommata ) ( Jordan & Gilbert, 1890).
- Diplobatis pictus Palmer, 1950.
- Discopyge tschudii Heckel, 1846.
- Narcine Atzi Carvalho & Randall, 2003.
- Narcine bancroftii ( Griffith & Smith, 1834).
- Narcine brasiliensis ( Olfers, 1831).
- Narcine brevilabiata Bessednov, 1966.
- Narcine brunnea Annandale, 1909.
- Narcine entemedor Jordan & Starks, 1895.
- Narcine indica Henle, 1834.
- Narcine insolita Carvalho, Seret & Compagno, 2002.
- Narcine lasti Carvalho & Seret, 2002.
- Narcine leoparda Carvalho, 2001.
- Narcine lingula Richardson, 1846.
- Narcine maculata ( Shaw, 1804).
- Narcine oculifera Carvalho, Compagno & Mee, 2002.
- Narcine prodorsalis Bessednov, 1966.
- Narcine rierai ( Lloris & Rucabado, 1991).
- Narcine tasmaniensis Richardson, 1841.
- Narcine timlei ( Bloch & Schneider, 1801).
- Narcine vermiculatus Breder, 1928.
- Narcine westraliensis McKay, 1966.