دراسة تصنيفية لثلاثة أنواع من أسماك جنس البلم في المياه البحرية العراقية

Abstract EN

Species of genus Thryssa in Iraqi marine water were studied during the period from March to November 2010.

Three species were recorded T.

whiteheadi Wongratana, 1983, T.

mystax (Schneider, 1801) and T.

vitrirostris (Gilchrist and Thompson, 1908).

The first type (T.

whiteheadi) is characterized that the tip of the snout lies above the level of eye center, the upper tip of maxillary bone projects just a little beyond the operculum, and the number of branching rays of the anal fin varies between 40-43.

While the tip of the snout in the other two types (T.

mystax and T.

vitrirostris) lies at level of eye center.

These two latter types are different in the length of the upper maxillary bone, which reaches to the base of first pectoral fin ray in the former while exceeds a little beyond the base of the first pectoral fin ray in the second; the number of branching rays in the anal fin varies from 32-33 in the former and from 37-38 in the latter.

Lower gill raker of the first arch ranged from 18 to 19 in T.

whiteheadi, 15 to 16 in T.

mystax and 20 to 21 in T.

vitrirostris.