Coilia dussumieri

Coilia dussumieri is a species of marine fish that belongs to the family Engraulidae, commonly known as anchovies. This species is native to the coastal waters of the Indo-West Pacific region, particularly around India, Pakistan, and the Arabian Peninsula.

Coilia dussumieri, also known as Dussumier's anchovy, is a small pelagic fish that inhabits coastal waters. It is an important species in local fisheries and is used for human consumption, often being dried or processed into fishmeal. This species is recognized for its distinctive morphology and plays a role in the food web of its habitat, serving as prey for larger fish and marine mammals.

IDENTIFYING FEATURES

SIZE:

• Coilia dussumieri is a small fish, typically reaching a length of about 15-20 cm, though individuals can grow up to 25 cm.

BODY SHAPE:

•  The body is elongated and laterally compressed, giving it a slender appearance. The fish has a characteristic tapering tail.

COLORATION:

• The body is usually silver with a slight bluish or greenish tint along the back. The belly is lighter, often white or pale silver.

HEAD:

•  The head is relatively large compared to the body, with a pointed snout. The eyes are large and prominent.

FINS:

•  It has a single dorsal fin located in the middle of the body, a forked caudal fin, and small pectoral and pelvic fins. The anal fin is elongated, running almost the entire length of the body from the midsection to the tail.

MOUTH:

•  The mouth is large and terminal, with a protruding lower jaw, which is typical of species that feed in the water column.

UNIQUE FEATURES

PROLONGED ANAL FIN:

• One of the most distinctive features of Coilia dussumieri is its elongated anal fin, which extends from the middle of the body almost to the base of the tail. This feature helps distinguish it from other anchovy species.

GAS BLADDER:

• Coilia dussumieri has a well-developed gas bladder, which aids in buoyancy control, allowing the fish to maintain its position in the water column with minimal energy expenditure.

HABITAT SPECIFICITY:

• This species is particularly adapted to brackish and coastal waters, making it different from other anchovies that may inhabit more open ocean environments.

MORPHOLOGY

SKELETON:

• Coilia dussumieri has a typical teleost skeleton with numerous small bones, which contributes to its flexibility and agility in the water.

SCALES:

• The scales are small, cycloid, and loosely attached, often shedding easily when handled.

GILL RAKERS:

• The gill rakers are fine and numerous, adapted for filtering small planktonic organisms from the water, which constitute the primary diet of this species.

TEETH:

The species has small, fine teeth on the jaws, which are suited for grasping small prey items.

REPRODUCTION

SPAWNING SEASON:

• Coilia dussumieri typically spawns during the warmer months, from late spring to early summer, when water temperatures are optimal for egg development.

FERTILIZATION:

• The species exhibits external fertilization, where eggs and sperm are released into the water column.

EGGS:

• The eggs are small, pelagic, and buoyant, allowing them to drift with the currents until they hatch.

LARVAL STAGE:

• The larvae are planktonic and go through several developmental stages before settling into their juvenile form. The early life stages are highly vulnerable to predation.

HABITAT

GEOGRAPHICAL DISTRIBUTION:

• Coilia dussumieri is found in the Indo-West Pacific region, particularly in the coastal waters of India, Pakistan, and the Arabian Peninsula.

HABITAT TYPE:

• This species prefers shallow coastal waters, often found in estuaries, brackish lagoons, and near river mouths. It can tolerate a wide range of salinities, making it well-suited to environments where freshwater mixes with seawater.

DIET:

• Coilia dussumieri primarily feeds on plankton, including small crustaceans, copepods, and larval fish. It uses its fine gill rakers to filter food from the water.

ECOLOGICAL ROLE:

• The species plays a significant role in the coastal marine ecosystem, serving as both a consumer of plankton and prey for larger predators such as larger fish, birds, and marine mammals.