Saturday, 10 October 2015

Spearfish


Name
The shortbill spearfish (Tetrapturus angustirostris) is a species of marlin native to the Indian and Pacific Oceans with occasional records from the Atlantic Ocean. Shortbill spearfish are commonly known as Hebi in Hawaii.

Appearance
Two important characters are shared by belone (Mediterranean Spearfish) and angustirostris (shortbill spearfish) and in these characters they differ from all their allies: 1) A high dorsal spine count; 50 (above) .2) An anteriorly placed anus; distance from anus to the origin of the anal fin 7.6-11% of body length in belone and 9.6% in angustirostris. The flattened profile from the spinous dorsal to the bill tip and the lack of spots in the dorsal fin are additional characters that are probably important. Dorsal spines (total): 0; Dorsal soft rays (total): 51-57; Anal spines: 0; Anal soft rays: 18 - 23. Dark blue above, blue splattered with brown on the sides, silvery white below; 1st dorsal fin plain dark blue, other fins brown or dark brown; anal fin bases with tinges of silvery white. This species can reach a length of 230 cm (91 in), though most do not exceed 190 cm (75 in). The maximum recorded weight for this species is 52 kg


Location
Comoros, Kenya, Madagascar, Mauritius, Mozambique, RĂ©union, Seychelles, Somalia, South Africa, Tanzania, Bangladesh, Chagos Is. China, India, Indonesia, Japan, Korea (South), Maldives, Myanmar, Oman, Pakistan, Philippines, Ryukyu Is. Sri Lanka, Taiwan, Costa Rica, El Salvador, Guatemala, Honduras, Mexico, Nicaragua, Panama, USA, American Samoa, Australia, Cook Is. Fiji, French Polynesia, Guam, Hawaii, Kermadec Is. Marshall Is. Micronesia, New Caledonia, New Zealand, North Marianas, Palau, Papua New Guinea, Samoa, Tonga, Tuvalu, Wake I. Chile, Colombia, Ecuador, Peru.

Habitat
Indian and Pacific: tropical and temperate waters. Although some stray individuals are found in the Atlantic Ocean, this species is believed to have its spawning grounds and principal populations only in the Pacific and Indian Oceans. Highly migratory species, Oceanic and epipelagic, found above the thermocline .

Spawning Season/Location
Spawning is believed to occur mainly during the winter months, especially in warm offshore currents with surface temperature of about 25°C.

Reproduction
Fertilization is external open water substratum egg scatterers and are non guarders of their young 

Diet
Lancetfish, Bullet tuna , Frigate tuna, Skipjack tuna , Pomfret, Flying fish , Snake mackerels or escolars. Butterfishes, squids and cuttlefishes 

Predators
Shortbill spearfish of 30 to 40 pounds (14 to 18 kg) have been recorded as feed items by Kona blue marlin fishermen, Tunas have been known to eat juveniles and larvae of shortbill spearfish

Edible 
Hebi (Shortbill Spearfish) has white to pink colored flesh that is somewhat softer than that of Nairagi (White Marlin) or Kajiki (Blue Marlin). Its flavor is mild (although more pronounced than ahi(Tuna). It is one of several species of billfish, which are suitable for grilled or broiled “catch of the day” menu items in restaurants around Hawaii.
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Name
The Mediterranean spearfish (Tetrapturus belone) or is a species of marlin native to the Mediterranean Sea where it is particularly common around Italy.

Appearance
Two important characters are shared by belone and angustirostris and in these characters they differ from all their allies: 1) A high dorsal spine count; 50 (above) .2) An anteriorly placed anus; distance from anus to the origin of the anal fin 7.6-11% of body length in belone and 9.6% in angustirostris. The flattened profile from the spinal dorsal to the bill tip and the lack of spots in the dorsal fin are additional characters that are probably important. Colour dark blue on dorsal side and silvery white laterally and ventrally , no rows of vertical bars or spots on body , first dorsal fin membrane blue black and no spots , remaining fins brown to black .Elongated and much compressed body, covered with densely embedded scales ending in 3-5 posterior points. Upper jaw prolonged into a slender spear, short in length about 18% of body length, round in cross section. Head profile (nape) between pre orbital region and origin of first dorsal fin nearly straight. First dorsal fin long and rather high throughout its length, height of anterior part slightly greater than body depth. Pelvic fins slightly shorter than twice the pectoral fin length. Tips of first dorsal and first anal fins rounded. Pectoral fin narrow and short. Caudal peduncle with double keels on each side, with a caudal notch on the dorsal and ventral surface. Two separated anal fins, first anal 11-15 rays, and second anal fin with 6-7 rays.  Dorsal spines: 39-46 rays in first fin, 5-7 rays in second fin. Single lateral line visible, curved above pectoral fin, then straight towards tail. Anal opening far forward, located at distance from origin of first dorsal equal to height of longest anal fin ray. Vertebrae: 12 precaudal plus 12 caudal. No gillrakers, jaws and palatines with small teeth in adults. This species can reach a length of 240 centimetres (94 in) Total Length. The heaviest recorded specimen weighed in at 70 kilograms (150 lb
Location
Algeria, Egypt, Libya, Morocco, Tunisia, Cyprus, Israel, Lebanon, Syria, Turkey, Albania, Bosnia Herzegov. Croatia, France, Greece, Italy, Malta, Monaco, Montenegro, Slovenia, Spain, 

Habitat
It is an open-water fish, being found within 200 metres (660 ft) off the surface.

Spawning Season/Location
Mediterranean spearfish are batch spawners, shedding batches of hydrated oocytes, in separate spawning events, most likely directly into the sea where fertilization occurs. Spawning appears to occur within the Mediterranean Sea. Spawning success has been identified in the Strait of Messina (Sicily) from reported eggs and larvae collected in the plankton. It has been suggested that Mediterranean spearfish probably spawns in late spring, based on the occurrence of eggs and larvae recorded in May, and juveniles found in October. 

Reproduction
Eggs are pelagic, spherical and transparent; ovulated eggs are on average 1.48 mm in diameter and contained an oil globule. This species is of minor importance to commercial fisheries. Marine Biologists estimate that this species matures at 2-years and has a lifespan of only 5-years.

Diet
Garfish ,Pilot fish, Atlantic saury, traces of dorado/dolphin fish ,Needle fish , Herrings, Shads, Sardines, Hilsa, and Menhadens, Inkfish , Blanket octopus ,Southern shortfin squid or Broadtail shortfin squid.

Edible
This species is highly exposed to lipophilic xenobiotic contaminants, meaning from my understandings, means its very susceptible to pollutants, the pollutants can stay or cause defects (weaken) the fish , much like antibiotics, the elements is not produced within the body and are placed there in a man made way, thus results in an embryo with the elements(contaminant) attached to it, and much like an oysters the body protects its self by releasing hormones continuously in till detoxification occurs , The body removes xenobiotics by xenobiotic metabolism. This consists of the deactivation and the excretion of xenobiotics, and happens mostly in the liver, Excretion routes are urine, feces, breath, and sweat. Organisms can also evolve to tolerate xenobiotics. An example is the co-evolution of the production of tetrodotoxin in the rough-skinned newt and the evolution of tetrodotoxin resistance in its predator, the common garter snake. since one of the fishes the spearfish prey on mainly the Lancet fish, which is the predator of the pufferfish, maybe we see tetrodotoxin resistance here ? are most likely found in oxygenated rich waters 

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Name
The Roundscale spearfish (Tetrapturus georgii) or "hatchet marlin", long thought to be a variant of the white marlin distinguished by dorsal and anal fins with a chopped-off rather than rounded appearance, has recently been confirmed as a separate species in the Tetrapturus genus, the Roundscale spearfish. Nearly indistinguishable from white marlin
Appearance
Roundscale spearfish are found in both the eastern and western Atlantic. They bear an uncanny resemblance to white marlin, but can be distinguished by their longer branchiostegals and the position of the anus which is located four to six inches forward of the anal fin. This later characteristic separates the spearfishes from all other billfish. The body oblong, compressed laterally, minute teeth in bands on jaw and palatines. the first dorsal fin low, but its anterior part inform of high lobe, height being almost equal to the body depth, second dorsal fin with 7 rays, first anal fin with 12 to 15 spiny rays ,second anal fin with 6 to 7 soft rays located under second dorsal fin and similar to it in shape, pelvic fins consist of single spine and 1 or 2 soft rays ,which are relatively shorter in adults than in young , Origin of second anal fin infront of 2nd dorsal fin vertically. Colouration of live animals have been difficult to determine, overall body colour ,blue black dorsally, brown laterally and silver white ventrally. specimens can be extremely colourful, where approximately 18-20 light blue stripes dorsally and approximately 17 silvery white lateral stripes generally originating underneath or associated with the dorsal stripes, lateral stripes fade into a silvery white ventral portion of the body, the first and second dorsal fins medium dark blue but without the distinct spotting, the first anal fin silvery white at the origin to the body darkened distally to a blue colour, the second anal fin was silvery white with a dusky posterior margin , the pectoral fins were blue black with some areas of lighter blue. This species can reach a length of 184 centimetres (72 in) and the heaviest recorded fish weighed in at 21.5 kilograms (47 lb).

Location
Algeria, Canary Is. Madeira Is. Morocco, Tunisia, West Sahara, Gibraltar, Italy, Portugal, native to the eastern Atlantic Ocean from Portugal to Madeira, the Canary Islands to northern Africa and the western Mediterranean Sea to Sicily.

Habitat
It is suspected that it may be more widespread. It is believed to inhabit open waters

Spawning Season/Location
no known evidance of reproduction occuring in waters 

Reproduction
Fertilization is external open water substratum egg scatterers and are non guarders of their young

Diet
Atlantic Mackerel, Squid, little is known of this species diet - one can expect its the same as Marlin 
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Name
The longbill spearfish (Tetrapturus pfluegeri) is a species of marlin 

Appearance
The pectoral fins of the shortbill and Mediterranean spearfishes barely reach to the curve of the lateral line. In the longbill spearfish they extend beyond the curve. The longbill spearfish has more elements (45 to 53) in the first dorsal fin than any other Atlantic billfish. The shortbill spearfish of the Pacific has approximately the same count (47 50 elements), but the Mediterranean spearfish has fewer (39 46). The lateral line is single and arches above the pectoral fins. This species can reach a length of 254 centimetres (100 in) FL and the maximum weight recorded is 58 kilograms (128 lb). First dorsal fin long and pointed at anterior part ,high throughout its length, first anal fin tip pointed and anal opening about the heights length of the anal fin infront of anal fin , lateral scales narrow with multiple points, sometimes shows rows of stripes, gonads asymmetrical

Location
native to the Atlantic Ocean where it is found above the thermocline in open waters

Habitat
Oceanic and epipelagic, found above the thermocline .

Spawning Season/Location
They spawn once a year. Season or location is unknown

Reproduction
Fertilization is external open water substratum egg scatterers and are non guarders of their young

Diet
it feeds on pelagic fishes such as needlefish, tuna, and jack, as well as squids.






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Conclusions
All spearfish examine a scale with pointed ends
all anal fin heights are proportional to anal opening either by more than half the height
slender bodies except in roundscale spearfish slightly identical to white marlin
shorter bills proportionate to true Marlin figures

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