Y-bar shrimp goby

The Y-bar shrimp goby, scientifically known as Cryptocentrus fasciatus, is a tropical, reef-associated marine fish commonly found in the Indo-West Pacific region, stretching from East Africa to Melanesia and the Great Barrier Reef. This fish typically resides in depths ranging from 5 to 20 meters (approximately 16 to 66 feet), although it is most often found between 5 and 15 meters (16 to 49 feet). It can reach a maximum length of about 14 centimeters (5.5 inches).

Characterized by its vibrant and variable coloring, the Y-bar shrimp goby can appear mostly black with pale spots or white saddles on its head and back, sometimes taking on a yellow hue. Its appearance includes several distinct features: dorsal spines number between 6 and 7, dorsal soft rays total 10, a single anal spine, and 9 anal soft rays. This species often presents in a variety of color patterns including barred, saddled, or mottled. The barred variant displays four brown saddles and a head adorned with white or bluish streaks, complemented by blue spots on the pelvic fins and a blue stripe on the anal fin. In contrast, the saddled type has a dark brown body with whitish saddles, and the mottled variant is noted for four diffuse brown bars on its sides, with a mix of white and bluish spots on the head. The anal fin exhibits blue stripes across the varieties. A notable physical trait is its rounded caudal fin, and the body’s greatest depth is proportionally measured as 5.5 to 5.8 times in standard length, while the caudal fin measures 3.2 to 3.8 times in standard length.

The Y-bar shrimp goby often forms symbiotic relationships, living in burrows with alpheid shrimps. It is common to find two individuals sharing a burrow and they may display different color morphs. These fish typically inhabit clear coastal areas and inner reef sand slopes, forming small colonies.

The genus name Cryptocentrus comes from Greek roots "kryptos," meaning hidden, and "kentron," meaning sting, hinting at its discrete lifestyle and potential defensive attributes.