Practical Manual B.Voc

Etroplus surantensis

Phylum: Chordata

Class: Actinopterygii

Order: Perciformes

Family: Cichlidae

Genus: Etroplus











Etroplus suratensis is a euryhaline species that inhabits mainly brackish water and river mouths. It is an oval-shaped cichlid with a short snout, small mouth not extending past the front margin of the eye with a greyish-green colouration on the flanks, with 6 to 8 dark bars and a dark spot at base of the pectoral fin. Most scales on the sides are with a pearly spot (Costa 2007). Macrophytic fragments form the most important component of its diet along with molluscs, although detritus, diatoms, and animal matter are also ingested (De Silva et al. 1984). Many aspects of this species was studies in order to assess it's suitability for culture in ponds and tanks by Jayaprakash et al. (1990).Adults engage in altruistic multiple parental care where several adults care for a single brood that presumably were spawned by only two of the adults (Ward and Wyman 1977).

Mugil cephalus
Phylum: Chordata

Class: Actinopterygii

Order: Mugiliformes

Family: Mugilidae

Genus: Mugil



Mugil cephalus is cosmopolitan in the coastal waters of most tropical and subtropical zones. In the western Atlantic Ocean, it is found from Nova Scotia, Canada south to Brazil, including the Gulf of Mexico. It is absent in the Bahamas and the Caribbean Sea. In the eastern Atlantic Ocean, the striped mullet occurs from the Bay of Biscay (France) to South Africa, including the Mediterranean Sea and the Black Sea. The eastern Pacific Ocean range includes southern California south to Chile.

The flathead grey mullet is catadromous, frequently found coastally in estuaries and freshwater environments. Adult mullet have been found in waters ranging from zero salinity to 75‰, while juveniles can only tolerate such wide salinity ranges after they reach lengths of 4–7 cm. Adults form huge schools near the surface over sandy or muddy bottoms and dense vegetation and migrate offshore to spawn in large aggregations. The larvae move inshore to extremely shallow water, which provides cover from predators as well as a rich feeding ground. After reaching 5 cm in length, these young mullet move into slightly deeper waters.

Flathead grey mullet is a diurnal feeder, consuming mainly zooplankton, dead plant matter, and detritus. Mullet have thick-walled gizzard-like segments in their stomach along with a long gastrointestinal tract that enables them to feed on detritus. They are an ecologically important link in the energy flow within estuarine communities. Feeding by sucking up the top layer of sediments, flathead grey mullet remove detritus and microalgae. They also pick up some sediment which functions to grind food in the gizzard-like portion of the stomach. Mullet also graze on epiphytes and epifauna from seagrasses as well as ingest surface scum containing microalgae at the air-water interface. Larval flathead grey mullet feed primarily on microcrustaceans. Copepods, mosquito larvae, and plant debris have been found in the stomach contents of larvae under 35 mm in length. The amount of sand and detritus in the stomach contents increases with length, indicating that more food is ingested from the bottom substrate as the fish matures.

Eleutheronema tetradachylum

Phylum: Chordata

Class: Actinopterygii

Order: Perciformes

Family: Polynemidae

Genus: Eleutheronema


Dorsal spines (total): 9; Dorsal soft rays (total): 13-15; Anal spines: 3; Anal soft rays: 14 - 16. Pectoral filaments 4; fin membranes vivid yellow in life, except in large specimens, > ca 35 cm SL. Vomer with deciduous tooth plates on both sides, except in juveniles. Posterior part of maxilla deep, 3-4% of SL. Short tooth plate extension onto lateral surface of lower jaw. 7-9% SL (Ref. 41639).

Adults occur mainly over shallow muddy bottoms in coastal waters. Also enter rivers (Ref. 3479, 6390, 11230). Juveniles found in estuaries. During winter, adults ascend the rivers. They usually form loose schools, although larger fish are more often observed in pairs or singly (Ref. 6390). Feed on prawns and fish (largely members of Mugilidae, Engraulidae, and Sciaenidae) with occasional polychaetes. Frequency of crustaceans to fish in the diet varies seasonally. Larvae (7-30 mm TL) feed mainly on copepods and mysids but also take shrimps and prawn larvae (Ref. 57343). Juveniles (31-60 TL) feed on prawns shrimps and mysids (Ref. 57343). Protandrous hermaphrodites. Marketed fresh, frozen, and dried or salted.