Tuesday, 11 September 2012

Striped Marlin


Name
The striped marlin, Tetrapturus audax, is a species of marlin found in tropical to temperate Indo-Pacific oceans not far from the surface. It is a large commercial game fish with a record weight (at 1982) of 190 kg, and a maximum length of 420 cm. The striped marlin is a predator that hunts during the day from close to the surface to about 100 metres or so.  

Appearance 
No dorsal spines, Dorsal soft rays 42-48, No anal spines, Anal soft rays 18 - 24. Body elongated and compressed, medium sized beak on the upper jaw, two dorsal fins, the height of the first progressively downsizing to the second, short anteriorly, taller in the middle, then becoming shorter posteriorly, pectoral fins falcate and flexible with 18 to 22 rays, body densely covered by small embedded scales with 1 or 2 bluntish points, back dark blue, belly silvery, membrane of first dorsal fin blue black without dark spots, flanks with about 20 bluish stripes. Blue-black above and silvery white below, with about 15 rows of cobalt-colored stripes, 1st dorsal fin dark blue, other fins dark brown sometimes with a tinge of dark blue, anal fin bases with a tinge of silvery white. One of the most interesting things about the striped marlin is that it can actually change colors. When a marlin gets excited, usually while feeding or courting, its stripes may light up from regular blue to a phosphorescent blue or lavender. After a marlin dies, it also develops conspicuous stripes along the sides of its body.

Location
Amer Samoa, Andaman Is, Angola, Australia, Bangladesh, Cambodia, Chagos Is, Chile, Christmas I. Colombia, Comoros, Cook Is, Costa Rica, Djibouti, Ecuador, El Salvador, Eritrea, Fiji, Fr Polynesia, Galapagos Is, Guam, Guatemala, Hawaii, Honduras, India, Indonesia,Iran, Japan, Kenya, Kermadec Is, Kiribati, Korea Rep, Kuril Is, Madagascar, Malaysia, Maldives, Marquesas Is, Marshall Is, Mauritius, Mexico, Micronesia, Mozambique, Myanmar, N Marianas, New Caledonia, New Zealand, Nicaragua, Oman, Pakistan, Palau, Panama, Papua N Guin, Peru, Philippines, Reunion, Ryukyu Is, Samoa, Seychelles, Singapore, Solomon Is, Somalia, South Africa, Sri Lanka, Tahiti, Taiwan, Tanzania, Thailand, Tokelau, Tonga, Tuamotu Is, Tuvalu, USA, Vanuatu, Viet Nam, Wake I. Yemen,

Habitat
Epipelagic and oceanic species, usually found above the thermocline. Generally inhabit Subtropical 20°C - 25°C waters. Most dominant and widely distributed of all billfishes. Their abundance increases with distance from the continental shelf. Usually seen close to shore only where deep drop-offs occur. Mostly solitary, but forms small schools by size during the spawning season

Spawning grounds/seasons
Spawning occurs in Indonesia from January to February located around the Banda and Timor Seas, March and May in the Bay of Bengal Sea, May to June in the Eastern Pacific Ocean, October to December in the Northeastern Indian Ocean, September only in Australia located around Southern Coral Sea, November to December in Southwest Pacific Ocean, December to January in the Western Indian Ocean and May to June in the Western North Pacific Ocean

Reproduction
Dioecism as in males and females are separated by gender,external fertilization , non guarders of their eggs, open water/substratum egg scatterers, Larvae are most abundant in the respective local early summers. The seasonal occurrence of mature females coincides with that of the larvae. The lower temperature limit in the distribution of larvae is approximately 24°C, both in the Indian and Pacific Oceans. Spawning sites are between 10°S and 30°S in Southwest Pacific and 10°S and 20°S in northeastern Indian Ocean.

Diet
Snouted lancetfish, Australian salmon, Bullet tuna, Pacific and Atlantic saury also known by the name mackerel pike, anchovies, cornetfish, Snake mackerel , Veined Squid , Cape Hope Squid or Chokka , European Squid , Wellington flying squid , argonauts , White trevally , blue pilchard,Australian pilchard, blue-bait, Californian pilchard, Chilean sardine, Japanese pilchard, Pacific sardine, and Southern African pilchard. chub mackerel , Pacific jack mackerel 


Sunday, 9 September 2012

Leatherjacket fish/skipjack/leather jack



Name
The leatherjacket fish, skipjack or leather jack, Oligoplites saurus, is a jack and member of the Carangidae family. Leather jack may also refer to other members of the Carangidea family, such as the pilot fish. Leatherjack may also refer to the smooth leatherjacket, a member of the Monacanthidae family.


Location
Anguilla, Antigua Barb, Argentina, Aruba, Barbados, Belize, Br Virgin Is, Brazil, Cayman Is, Colombia, Costa Rica, Cuba, CuraƧao I. Dominica, Dominican Rp, Ecuador, El Salvador, Fr Guiana, Galapagos Is, Grenada, Guadeloupe, Guatemala, Guyana, Haiti, Honduras, Jamaica, Martinique, Mexico, Montserrat, Nicaragua, Panama, Peru, Puerto, Saint Lucia, St Kitts, St Vincent, Suriname, Trinidad, Turks Caicos, Uruguay, US Virgin Is,USA, Venezuela.


Habitat 
Subtropical, Sublittoral areas where sunlight reaches the ocean floor, brackish waters, reef associated. 

Appearance
Dorsal spines 5 - 6, Dorsal soft rays 19-21, Anal spines 2-3, Anal soft rays 18 - 21. Body elongate and strongly compressed, posterior end of upper jaw reaching posterior rim of eye, upper jaw teeth small and villiformed , lower branch of first gill arch with 14 to 18 gill rakers, scales small visible needle-shaped and embedded in the skin, back is blue green, flanks and belly silvery to white sometimes with yellow or golden highlights, pectoral and caudal fins yellowish , Dorsal fin has 5 nearly separate spines "Caution- handle fish with care as 4-6 spines in front of the soft dorsal fin rays, 3-5 lower spines located infront of lower soft fin rays are like hypodermic needles covered with slime hidden in a concave which is irritable when it has punctured skin"   



Diet

Shrimp, Prawns, Herring, Scaled sardines, Anchovies, American silver perch.

Method of catching 
Small lures ,flies blue to silver in colour reflected work best , live fish. 

Edible 
Traditionally, the leather jacket has not been eaten, however recently with large scale farming of the fish, it has become a common fish at market. The fish has a mild oily taste similar to spanish mackerel or bluefish. occurrences of disease has been associated with the fish.




Spawning ground/season 
Max length 35.0 cm, common length 27.0 cm. High to minimum population doubling in less than 15 months , spawning grounds and seasons are unknown.