Calloplesiops altivelisComet

Geographic Range

Calloplesiops altivelis lives in the Indo-west Pacific, including areas such as East Africa, the Red Sea, Tonga, and the Line Islands (Wood, 1945; Randall, 1997). It also occupies areas in the Philippines eastward towards Mozambique and in the East Indies (Wheeler, 1975; McCosker, 1977).


C. altivelis inhabits tropical, coral reefs and is often found during the day hiding in caves and crevices (Allen, 1997; Randall, 1986). During the night, C. altivelis emerges from its hiding place and swims along the coral reef. It is found in water levels ranging from 4 to 30 meters with water temperatures between 24-26°C (McCosker, 1977; Froese and Pauly, 2002).

  • Aquatic Biomes
  • reef
  • Range depth
    4 to 30 m
    13.12 to 98.43 ft
  • Average depth
    15.5 m
    50.85 ft

Physical Description

Comets are dark brown to black with one white spot per scale (Froese and Pauly, 2002; Randall, 1986; Schultz, 1901). The white spots are found on its body, head and fins, except for the median and pelvic fins which have small blue spots and are lacking scales. The pectoral fin is clear with visible, yellow rays (Randall, 1986). Located at the base of the last dorsal rays is a black ocellus. An anterior lateral line, which includes 20-30 scales, ends beneath the rear base of the dorsal fin (Froese and Pauly, 2002; Randall, 1997; Shen, 1986; Wheeler, 1975). The dorsal ray is slightly elevated and contains a total of 11 dorsal spines and 8 to 9 soft rays, while the anal fin is also slightly elevated and contains a total of 3 spines and 9 soft rays. The caudal fin is relatively elongate (Froese and Pauly, 2002; Randall, 1997). C. altivelis is noted for being unique among its family members because of the sharp angle of its preoperculum and its small upper jaw (Wheeler, 1975). The fish can reach 16 cm in length (Randall, 1997; Wheeler, 1975).

  • Range length
    16 (high) cm
    6.30 (high) in


When comets first hatch they are dark colored, approximately 3 cm long, and able to feed immediatly (Michael, 2002). After the first two weeks of growth, their bodies lose pigmentation, turning white. At two months they begin to develop white spots on the dark head, and at about seven months the drab brown color spreads to the rest of the body (Field and Field, 1998; Michael, 2002). During the post juvenile stage of C. altivelis development, its sex is indeterminate (Field and Field, 1998).


Little is known of comet reproduction in the wild. In captivity, a single pair will mate when given rocky hiding places. Courtship and spawning take place among the crevices and caves. The female deposits a brown egg mass, using sticky threads to attach her hundreds of eggs to a protected rocky surface (Michael, 2002).

  • Breeding season
  • Average time to hatching
    5-6 days

Male C. altivelis protect the egg mass until hatching.


C. altivelis is a relatively shy fish and during the day is primarily found dwelling in reefs and caves, yet has been spotted showing activity in poorly lit areas (Field and Field, 1998; Randall, 1986). Beginning at twilight and throughout the night the fish is active in its search for food (Field and Field, 1998). The comet is a stalking predator that often approaches its prey with a sideways swim using the pectoral fins. When close enough it will lunge forward (Michael, 2002).

Communication and Perception

Food Habits

Unlike most members of Plesiopidae, C. altivelis does not feed on algae, but is instead a meat eater. Though harmless to humans, it is a nocturnal seeker, hunting crustaceans and small fish (Field and Field, 1998; Wood, 1945).

  • Animal Foods
  • fish
  • aquatic crustaceans


When C. altivelis is threatened, the fish puts its head into holes in reefs and changes the shape of its tail by expanding its caudal, anal and dorsal fins (McCosker, 1977). By doing this, the ocellus on its dorsal fin is fully visible and resembles an eye (Froese and Pauly, 2002; Randall, 1997; Randall, 1986; McCosker, 1977; Wood, 2002). Expanding its fins also exposes the gap between the dorsal and anal fin, which resembles a mouth (Randall, 1997). The shape of the fins combined with the ocellus and gap make the fish look like Gymnothorax meleagris, the white-spotted moray eel, which is much more dangerous to the would-be predators, and they often leave the comet alone (Froese and Pauly, 2002; Michael, 2002; Randall, 1997; Randall, 1986; Wood, 1945).

Ecosystem Roles

The comet acts as a predator on smaller fish and crustaceans in the reef environment (Field and Field, 1998). It also serves as a source of food for larger predators.

Economic Importance for Humans: Positive

Often C. altivelis is kept in aquariums as pets (Froese and Pauly, 2002).

Economic Importance for Humans: Negative

The comet is not known to have any negative impacts on humans.

Conservation Status

Other Comments

Calloplesiops altivelis was previously known as Barrosia barrosi and was thought only to be in shallow water located in the Island of Nias in Indonesia (Smith, 1969). Today this uncommon fish is also known as Steindachner and Marine betta (Randall, 1986; McCosker, 1977).


William Fink (editor), University of Michigan-Ann Arbor.

Kris Caulfield (author), University of Michigan-Ann Arbor.



Living in Australia, New Zealand, Tasmania, New Guinea and associated islands.

World Map

Pacific Ocean

body of water between the southern ocean (above 60 degrees south latitude), Australia, Asia, and the western hemisphere. This is the world's largest ocean, covering about 28% of the world's surface.

World Map

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.


an animal that mainly eats meat


uses smells or other chemicals to communicate


offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).

male parental care

parental care is carried out by males


having the capacity to move from one place to another.


specialized for swimming

native range

the area in which the animal is naturally found, the region in which it is endemic.


active during the night

pet trade

the business of buying and selling animals for people to keep in their homes as pets.


an animal that mainly eats fish


structure produced by the calcium carbonate skeletons of coral polyps (Class Anthozoa). Coral reefs are found in warm, shallow oceans with low nutrient availability. They form the basis for rich communities of other invertebrates, plants, fish, and protists. The polyps live only on the reef surface. Because they depend on symbiotic photosynthetic algae, zooxanthellae, they cannot live where light does not penetrate.


reproduction that includes combining the genetic contribution of two individuals, a male and a female


lives alone


uses touch to communicate


the region of the earth that surrounds the equator, from 23.5 degrees north to 23.5 degrees south.


Allen, G. 1997. Marine Fishes of Tropical Australia and South-east Asia. Peth, W.A.: Western Australian Museum.

Field, R., M. Field. 1998. Reef Fishes of the Red Sea, A guide to Identification. London, New York: Kegan Paul International.

Froese, R., D. Pauly. 2002. "Fishbase" (On-line). Accessed November 11, 2002 at

McCosker, J. 1977. Fright Posture of the Plesiopid Fish *Calloplesiops altivelis*: An Example of Batesian Mimicry. Science, 197: 400-401.

Randall, J. 1997. Fishes of the Great Barrier Reef and Coral Sea. Bathurst, N.S.W: Crawford House Publishing.

Randall, J. 1986. 106 New Records of Fishes From the Marshall-Islands Bulletin of Marine Science. Marine Biology, 38: 170-252.

Schultz, L. 1901. Fishes of the Marshal and Marianas Islands. Washington: U.S. Govt. Print Off..

Smith, J. 1969. The fishes of Seychelles. Grahamstown, Rhodes University: J.L.B. Smith Institute of Ichothyology.

Wheeler, A. 1975. Fishes of the World. New York: MacMillan Pub..

Wood, E. 1945. Reef fishes, corals and invertebrates of the South China Sea: including Thailand, Hong Kong, China, Malaysia, Taiwan, Singapore, Indonesia and the Philippines. London: New Holland.