No common name

Pterosagitta draco

ORDER

Aphragmophora

FAMILY Pterosagittidae

TAXONOMY

Sagitta draco (Krohn, 1853), Mediterranean Sea off Messina.

OTHER COMMON NAMES None known.

PHYSICAL CHARACTERISTICS

Individuals have 8-10 hooks, 6-10 anterior teeth, and 8-18 posterior teeth. Maximum adult body length is 0.43 in (11 mm), and the relative tail length is 38-45% of total body size. The body is firm, broad, and opaque. One pair of fins is present on the tail segment; fins are completely rayed and round. Head is fairly large. There is a large, broad collarette along the trunk and part of the tail. There are no gut diverticula. Eyes are small with T-shaped pigment spots. Seminal vesicles are present on the head and trunk, close to tail fin, and touch lateral fins. Ovaries are long, reaching the neck region; ova are large.

DISTRIBUTION

Epipelagic, occurring between 40°N and 40°S in all three oceans. HABITAT

Lives in the pelagic realm of tropical and subtropical oceans, at depths of 3-85 ft (10-300 m).

BEHAVIOR

Shows no evidence of diurnal vertical distribution. Rapid darting movements are made over short distances to catch prey.

FEEDING ECOLOGY AND DIET

Prefers small copepods. Feeds at night after moving to superficial layers.

REPRODUCTIVE BIOLOGY

Reproduction is dependent on water temperature and occurs several times a year. Hermaphroditic, and sperm is stored in the oviducts waiting for the eggs to mature. Fertilized eggs are released in sea water. There is no larval stage.

CONSERVATION STATUS Not listed by IUCN.

SIGNIFICANCE TO HUMANS None known. ♦

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