Alimentary canal anatomy and diet of the scomber japonicus (houttuyn, 1782)‎, at Hadhramout coast-Gulf of Aden

Abstract EN

-Chub mackerel Scomber japonicus (Scombridae) is a pelagic species that inhabits warm and temperate coastal waters of the Atlantic, Indian and Pacific Oceans.

Anatomical structure of the alimentary canal and diet of Scomber japonicus, are described based on 50 specimens (average length 22-40 cm) collected from landing site at coast of Mukalla (Gulf of Aden), during January-February 2016.

The mouth is large, angled at about 45", and opens terminally and slightly superiorly.

Small conical teeth (premaxillary, vomer and dentary) are present .

The gill rakers are long and flat with tall teeth at their distal ends.

The stomach is very muscular and capable of sizable distension.

There are 45-50pyloric caeca at the junction of the stomach and intestine.

The intestine is relatively tall, and the anus is located much more widely such as in some fishes.

The observed food items taken by S.

japonicus allow this fish to be considered as omnivorous.

Seventy percent of the stomachs and 74% of the intestines contained food items, whereas nearly 80% of the entire gastrointestinal tracts contained prey.

Sixteen percent of the stomachs were full.