cluster practicals

Scomberomorus
guttatus

Diagnostic
Features

First dorsal
fin with 15 to 18 spines, usually 16 or more; second dorsal with 18 to 24 rays,
usually 20 to 22, followed by 7 to 10 finlets; anal fin with 19 to 23 rays;
followed by 7 to 10 finlets, usually 8; pectoral fin rays few, 20 to 23,
modally 21.  Lateral line with many fine
auxiliary branches extending dorsally and ventrally in anterior third,
gradually curving down toward caudal peduncle. 
Vertebrae 19 to 22 precaudal plus 28 to 31 caudal, total 47 to 52,
usually 50 or 51.  Intestine with 2 folds
and 3 limbs. 

Colour:
sides silvery white with several longitudinal rows of round dark brownish spots
First dorsal fin membrane black  pelvic
and anal fins silvery white.

Habitat and
Biology

               

An
epipelagic, neriticspecies 

Based on
occurrence of ripe females and size of maturing eggs, spawning probably occurs
from April to July around Rameswaram Island between India and Sri Lanka (

Size

               

Maximum fork
length is 76 cm. Size at first maturity ranges between 48 and 52 cm total
length in southern India

Interest to
Fisheries

               

It is
utilized fresh or salted in most areas 
Although less abundant than the Indian mackerels (Rastrelliger spp. S.
guttatus is highly esteemed for food and commands a higher price in Thailand
and India

cluster practical notes

Indian
mackerel

Rastrelliger
kanagurta

Scientific
classification

Kingdom:             Animalia

Phylum:               Chordata

Class:     Actinopterygii

Order:   Perciformes

Family:  Scombridae

Genus: Rastrelliger

Species:               R. kanagurta

Rastrelliger
kanagurta

The Indian
mackerel (Rastrelliger kanagurta) is a species of mackerel in the scombrid
family (family Scombridae) of order Perciformes.[1] It is commonly found in the
Indian and West Pacific oceans, and their surrounding seas. It is an important
food fish and is commonly used in South and South-East Asian cuisine.

Distribution
and habitat

The Indian
mackerel is found in warm shallow waters along the coasts of the Indian and
Western Pacific oceans.  It is widely
found in Karnataka coastal belt and very popular fish food in Kudla.

Description

The body of
the Indian mackerel is moderately deep, and the head is longer than the body
depth. The maxilla are partly concealed, covered by the lacrimal bone, but
extend till around the hind margin of the eye.

These fish
have thin dark longitudinal bands on the upper part of the body, which may be
golden on fresh specimens. There is also a black spot on the body near the
lower margin of the pectoral fin. Dorsal fins are yellowish with black tips,
while the caudal and pectoral fins are yellowish. The remaining fins are dusky.

Indian
mackerel reach a maximum fork length of 35 centimetres (14 in), but are
generally around 25 centimetres (9.8 in) in length.

Habitat and
diet

The Indian
mackerel is generally found in shallow, coastal waters.  Adults of this species are found in coastal
bays, harbours and deep lagoons. They are commonly found in turbid waters rich
in plankton.[2]

Adult Indian
mackerel feed on macroplankton including the larvae of shrimp and fish.

Life history

The spawning
season around India, which is in the northern hemisphere, is between March and
September. Around Seychelles in the southern hemisphere, it is between
September and the following March.

Spawning
occurs in batches. The eggs are laid in the water and are externally fertilized.
The Indian mackerel do not guard their eggs, which are left to develop on their
own.

Juveniles
feed on phytoplankton like diatoms and small zooplankton including cladocerans
and ostracods. As they mature, their intestines shorten, and their diet changes
to primarily include macroplankton such as the larvae of shrimp and fish.

As food

the fish is
deep fried or pan fried with Rava or made into a spicy curry .