1.2.14 Bracket key

1.2.14 Bracket key

The second type of key in most of the fish taxonomical studies is the bracket key. This has the advantage that the couplets are composed of alternatives and are side by side so that comparisons could be made easily. This key is also more economical and space of because it is not indented. When properly constructed, this key will run forward or backward with equal facility by following numbers indicating the path that the various choices follow. The main disadvantage is that the relationship is not apparent to the eye.

1.

Body elongate, tail long and tapering; caudal fin not forked; upper pectoral rays produced as long filaments.

Coilia


Body moderately long, caudal forked; pectoral rays normal.

2

2.

Prominent silvery lateral stripe present.

Stolephorus


No silvery lateral stripes.

3

3.

Upper pectoral ray produced.

Setipinna


Upper pectoral ray not produced.

4

4.

No abdominal scutes in front of ventral fin.

Thrissina


Abdominal scutes extends from isthmus to vent.

Thryssa

Last modified: Tuesday, 24 January 2012, 6:34 AM