Diagnostic Description
(
Anglèis
)
fornì da Fishbase
A slim, graceful blue shark with a long, conical snout, large eyes, and curved triangular upper teeth with saw edges; pectorals long and narrow; no interdorsal ridge (Ref. 5578). Dark blue dorsally, bright blue on the sides, white ventrally (Ref. 5578). Tips of pectoral fins and anal fin dusky (Ref. 9997). The first case of diprosopus tetrophthalmus (cranofacial duplication) in a foetus of this species was reported from South Atlantic (Ref. 119190).
- Recorder
- Cristina V. Garilao
Life Cycle
(
Anglèis
)
fornì da Fishbase
Distinct pairing with embrace (Ref. 205). Viviparous (Ref. 26281), placental (Ref. 50449); 4-63 young in a litter (Ref. 9997); 4-135 (usually 15-30) pups (Ref.58048), about 35-44 cm at birth. Gestation period ranges from 9 to 12 months (Ref. 244).Sexual dimorphism is evident in skin thickness of maturing and adult females (Ref. 49562). Females have thicker skin layer than males of the same size (Ref. 49562).
Migration
(
Anglèis
)
fornì da Fishbase
Oceanodromous. Migrating within oceans typically between spawning and different feeding areas, as tunas do. Migrations should be cyclical and predictable and cover more than 100 km.
- Recorder
- Kent E. Carpenter
Morphology
(
Anglèis
)
fornì da Fishbase
Dorsal spines (total): 0; Dorsal soft rays (total): 0; Analspines: 0; Analsoft rays: 0
- Recorder
- Cristina V. Garilao
Trophic Strategy
(
Anglèis
)
fornì da Fishbase
Found worldwide in tropical and temperate seas; a pelagic species, sometimes advancing into coastal waters (Ref. 9137). Occurs on the continental shelf (Ref. 75154). Prefer temperatures of 7-16°C; usually found in deeper waters in the tropics (Ref. 5951). A carnivore (Ref. 9137). Parasites of the species include: Hepatoxylon squali pleurocercoid, Phyllobothrium dagnallium, Phyllobothrium sp. and Platybothrium parvum (Ref. 5951).
Biology
(
Anglèis
)
fornì da Fishbase
Oceanic, but may be found close inshore where the continental shelf is narrow (Ref. 6871, 58302). Usually found to at least 150 m (Ref. 26938). Maximum size from Ref. 128029. Reported from estuaries (Ref. 26340). Epipelagic, occasionally occurs in littoral areas (Ref. 58302). Feeds on fishes (herring, silver hake, white hake, red hake, cod, haddock, pollock, mackerel, butterfish, sea raven and flounders (Ref. 5951)), small sharks, squids, pelagic red crabs, cetacean carrion, occasional sea birds and garbage (Ref. 5578). Viviparous (Ref. 50449). Sexual dimorphism occurs in skin thickness of maturing and adult females (Ref. 49562). May travel considerable distances (one specimen tagged in New Zealand was recaptured 1,200 km off the coast of Chile) (Ref. 26346). Potentially dangerous to humans (Ref. 6871, 13513). Marketed fresh, dried or salted, and frozen; meat utilized for consumption, hides for leather and fins for soup (Ref. 9987). Sexually mature at 250 cm long and 4-5 years old. The female gives birth up to 80 young measuring 40 cm long, gestation lasts almost a year (Ref. 35388). Produces from 4 to 135 young a litter (Ref. 26938).
- Recorder
- Kent E. Carpenter
Importance
(
Anglèis
)
fornì da Fishbase
fisheries: minor commercial; gamefish: yes; price category: medium; price reliability: reliable: based on ex-vessel price for this species
- Recorder
- Kent E. Carpenter