Harlequin Prawn-goby

Overview

The harlequin prawn-goby (Cryptocentrus caeruleopunctatus) is a distinctive, bottom-dwelling fish native to the Red Sea, though it has recently expanded its range into the eastern Mediterranean. It is a peaceful, solitary species often found in clear, shallow coastal waters where it maintains a fascinating symbiotic relationship with alpheid snapping shrimp.

Distribution & habitat

Originally restricted to the Red Sea and the Gulf of Tadjoura, this goby has been recorded as an alien species along the Mediterranean coast of Israel and Turkey. It typically inhabits open, coarse sandy bottoms and silty areas adjacent to coral reefs or seagrass beds, where it can easily excavate its burrows.

Appearance

This species features an elongated body that transitions from a yellowish or tan color at the head to a darker, grayish-brown toward the tail. It is easily identified by its striking pattern of red spots encircled by blue rings, which are prominent on the head, anterior body, and dorsal fins. The body is further decorated with a series of diagonal, pale lines and scattered blue dots. It possesses a large mouth with thick lips and elevated, prominent eyes that allow it to scan for predators while remaining near the seabed.

Biology & behavior

The harlequin prawn-goby lives in a mutualistic partnership with a snapping shrimp. The shrimp digs and maintains a shared burrow, while the goby acts as a lookout. Because the shrimp has poor eyesight, the goby uses its keen vision to monitor for danger, signaling the shrimp with tail flicks when it is time to retreat into the safety of their burrow. It is a territorial fish that will defend its home against other members of its own species but is generally non-aggressive toward other fish.