Taxonomy of Finfish (1+2)

Procedure

Based on the exercise 5. separate the group of Perciformes.

The order perciformes is the most diverse one.

Acanthuroidei character

* Body deep and strongly compressed.

* Small scales;

* A strong, movable, forward-projecting spine mid-laterally on caudal peduncle.

Labroidei character

* Well developed teeth, united into plates in the parrotfishes;

* scales usually big and cycloid

* body compressed; usually colourful species. used for ornamental purpose

Blenniodei character

* Dorsal fin long; pelvic fins reduced, with 1 hidden spine and 2 to 4 soft rays, located ahead of pectoral fins;

* tentacles often present on head;

* anal fin spines two (one of them sometimes difficult to see)

* Upper and lower jaws each with broad band of conical teeth

Before going for identification the students has to familiarize the following key characters used to identify the suborder Labroidei

* Body shape

* Shape of scales

* Filamentous growth or extension of fins

* Scales in head region, cheek region

* Lateral line nature like interrupted or complete

* Teeth pattern and fuseness

* Caudal fin nature

* Dorsal and Anal fin spines and rays count.

* Colour pattern

* Nature of snout

* presence of scale in the cheek and operculam

* Predorsal scale count

* Gill rakers count

Before going for identification the students has to familiarize the following key characters used to identify the suborder Blenniodei:

* Lateral line continuous or discontinuous

* Anal fin with or without spines

* Gill opening

* Fringed flap

* spine and rays count in dorsal fin

Before going for identification the students has to familiarize the following key characters used to identify the suborder Acanthuroide

* Compressed deep body shape

* Presence of spine in the caudal peduncle

* Forward projecting spine in front of the dorsal

Based on the above character identify the following families using standard identification book or manual. Identify some of the species belong to these families.

BLENNIIDAE

* Small, scaleless , often elongate fishes

* Head often with cirri on eyes , nasal openings , nape , or cheeks.

* Gill openings continuous across lower surface of head

* Teeth incisor-like

* Dorsal fin with more segmented rays than spines

* Pelvic fins in advance of pectoral fins , pelvic-fin spine not visible externally , soft rays fewer than 5 ,

v sometimes deformed or absent.

* 2 spine in the anal fin often rugose bulbous swellings

CLINIDAE

* Small fishes

* Body elongate and often compressed

* Cirri present usually above eye

* Body with embedded small scales

* Scales cycloid with radii in all fields

* jaw teeth in more than 1 row.

* pelvic fins anterior to pectorals

* spines in the dorsal fin outnumbering soft rays

* Fin rays simple and unbranched

SIGANIDAE- spinefoots or rabbit fishes

* Mouth terminal, very small; jaws not protrusible

* Dorsal fin with XIII strong spines and 10 soft rays; preceded by a short, sharp, forwardly projecting spine ,

* Pelvic fins with II spines ( I strong inner and I outer spine, with 3 soft rays in between), a character unique to this family ;

* anal fin with VII spines.

ACANTHURIDAE :

* 1 or more spines or keeled bony plates on each side of caudal peduncle

* A continuous unnotched dorsal fin with IV to IX spines and 22 to 33 soft rays;

* anal fin with II or III spines and 18 to 31 soft rays ;

* caudalfin truncate to lunate, with 16 principal rays;

ZANCLIDAE ( Zanclus cornutus ):

* Beautiful ornamentalfishes with only one species.

* snout protruding;

* premaxilla protractile;

* dorsal fin with a long filament from third spine;

* adults with a pair of supraocular bony projections;

* no spine or keels on caudal peduncle.

LABRIDAE:

* Mouth terminal, usually with prominent lips;

* mouth slightly to extremely protrusible ; maxilla not exposed on cheek;

* teeth in jaws usually separate and caniniform, the anteriormost 1 or 2 pairs typically enlarged and often directed forward

* A single, long-based dorsal fin

CICHLIDAE:

* Head with a single nostril on each side. A single dorsal fin with XIII to XIX spines and 10 to 16 soft rays;

* anal fin with III (except XII or XIII in Etroplus ) spines and 7 to 12 soft rays ;

* Caudal fin typically rounded, truncate, or slightly emarginate (forked in Etroplus ).

* Lateral line interrupted , with 26 to 40 scales

SCARIDAE- Parrot fishes

* Head generally bluntly rounded anteriorly.

* Jaws at most only slightly protrusible;

* teeth usually fused to form a pair of beak-like plates in each jaw

* pharyngeal dentition strong consisting of interdigitating paired upper pharyngeals with rows of elongate molariform teeth

* Predorsal scales 3 to 8 rows

* single dorsal fin with IX flexible spines and 10 soft rays

* cheek scales rows 1 to 4

* Large cycloid scales

POMACENTRIDAE- damsel fishes:

* Eye medium sized, generally exceeding snout length.

* Mouth small, jaws equal and oblique.

* Small conical to incisiform teeth in jaws in a single row,

* A single dorsal fin with VII to XVII stout spines and 9 to 21 soft rays;

* anal fin with II spines and 9 to 16 soft rays ;

* Scales ctenoid.

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