Comet Longfin

The comet or marine betta (Calloplesiops altivelis) is a reef-associated tropical marine fish species belonging to the longfin family, Plesiopidae. This species inhabits depths ranging from 3 to 110 meters but is typically found between 3 and 45 meters. It is indigenous to the 🌊 Indo-Pacific Ocean and can attain a maximum length of 20 cm.

Adult specimens of this species typically reside near reefs, often inhabiting caves and crevices along drop-offs. The comet is a nocturnal organism, utilizing ledges and holes for concealment during daylight hours, and emerging at night to forage the reef for sustenance. A noteworthy feature of the comet is its dorsal fin, which resembles an eye-like pattern. When threatened, the comet will insert its head into a crevice, exposing its tail to imitate the appearance of a moray eel's head.

The comet is a predatory species, primarily consuming crustaceans and small fish. It approaches prey by swimming laterally and ambushing as the prey attempts to escape. Upon evasion, the prey frequently ends up moving towards the comet's mouth.

The species is characterized by having 11 dorsal spines and 8 to 10 dorsal soft rays; 3 anal spines and 9 anal soft rays. It possesses 19-20+9-10 tubed lateral-line scales, and its body depth is measured at 2.5-2.7 in standard length (SL). Additionally, the dorsal and anal fins are elevated posteriorly, and the caudal fin is rounded. The fish's coloration includes a brownish-black head and body with small pale blue spots. Its vertical and pelvic fins are dark orange-brown with numerous small blue spots, and the dorsal fin has a blue-ringed black ocellus located above the last three dorsal rays. The upper caudal rays are marked by yellow spots, while the pectoral rays are bright yellow with a transparent fin membrane.

The comet is found across the Indo-Pacific region, spanning from the 🌊 Red Sea and East Africa to 🇹🇴 Tonga and the Line Islands. Notably, male comets assume responsibility for guarding the eggs during reproduction.