Taxonomy of Finfish (1+2)

Procedure

Order Pleuronectiformes

• Based on the exercise 11. separate the group of Plueronectiformes  pr using the following characters.

• Eyes on only one side.

• Dorsal and anal fin base with long base.

• Body cavity small.

• Six or seven branchiostegal rays

• Adults without swimbladder.upper side pigmented and lower side light coloured.

 

Group the fishes based on the following character.

Psettodidae

• Body oval-shaped, flat but fairly thick;

• Caudal peduncle deeper than long.

• Head length 3.2 to 3.6 times in standard length.

• Both eyes on right or left side of head; upper eye on dorsal surface of head.

• Supramaxillary bone well developed . Mouth large, extending well beyond posterior margin of lower eye; lower jaw projecting.

• Teeth large canines, many with barbed tips.

• Vomer and palatines with teeth.

• Preopercular margin easily seen, not hidden by skin or scales .

• Dorsal-fin origin well posterior to upper eye ; caudal fin free from dorsal and anal fins ,

• Dorsal and anal fin anterior spinous

• Pelvic fins with I spine and 5 soft rays , and nearly symmetrically placed on each side of midventral line.

• Lateral line present on both sides of body,

Bothidae:- Left eye flounder

• Dorsal fin origin anterior to upper eye; no spines in fins;

• Lateral line of eyed side with high arch over pectoral fin ; lateral line absent below lower eye. ;

• Pelvic fin on eyed side on midventral line with origin anterior to that of pelvic fin of blind side, pelvic fin of blind side above midventral line;

• Urinary papilla on eyed side;

• Eyes nearly always on left side of head, reversals rare

Paralichthyidae: -

• Dorsal-fin origin anterior to posterior margin of upper eye; no fin spines;

• Lateral line with high arch over pectoral fin,

• Supratemporal branch of lateral line present;

• Urinary papilla on eyed side ; eyes nearly always on left side of head

Pleuronectidae:- Right eye flounders

• Dorsal-fin origin anterior to posterior margin of upper eye; no fin spines;

• Urinary papilla on eyed side;

• Eyes nearly always on right side of head

• Anterior dorsal-fin rays and rays of pevic fin on eyed side greatly elongate in Samaris , the only genus with a commercial species in the area,

Soleidae:

• dorsal-fin origin anterior to posterior margin of upper eye;

• no fin spines;

• margin of preopercle not distinct, covered with skin and scales;

• lower jaw not protruding;

• eyes on right side of head.

Citharidae:

• dorsal-fin origin anterior to posterior margin of upper eye;

• no spines in dorsal and anal fins;

• lateral line with high arch over pectoral fin; gill rakers elongate, not tooth-like;

• eyes normally on left side of head in some species and right side of head in other species,.

Cynoglossidae:

• Dorsal-fin origin anterior to posterior margin of upper eye;

• No fin spines; dorsal and anal fins joined to pointed caudal fin;

• Only 1 pelvic fin in most species; pectoral fins absent;

• Margin of preopercle not distinct,covered with skin and scales;

• Lower jaw not protruding, rostral hook present below mouth (except in Symphurus );

• Eyes on left side of head

 

List of fishes available in our region.

• Psettodes erumei (Bloch and Schneider, 1801) .

• Pseudorhombus triocellatus (Schneider, 1801)

• Zebrias quagga (Kaup, 1858)

• Samaris macrolepis Norman, 1927

• Cynoglossus arel (Schneider, 1801)

Based on the figures given identify some of the similar species available in your region.