GUMBALHA



English Name: Bluestripe herring

Family: CLUPEIDAE

Local Name: Gumbalha

Order: Clupeiformes

Size: Max. 14 cm

Distinctive Characters: Dorsal fin with 17-20 rays.Anal fin with 17-19 rays. Pectoral fin with 15-16 rays. Body depth 3.3-5.5 in standard length. Fusiform and moderately slender body. Belly with a distinct scutes. Top of head with few fronto-parietal striae, a broad wing-like scales almost hidden beneath the overlapping predorsal scales.

Colour: Back bluish green without spots. Flanks silvery with an electric blue line preceded by two orange spots.

Habitat and Biology: In daytime forms dense schools in shallow lagoons. During night time moves into deeper water. Feeds on zooplankton mainly at night.

Distribution: Indo-Pacific.

Remarks: Herklorsichthys quadrirnaculatus forms large daytime schools in shallow lagoons, often in association with schools of Bigeye scad.Sometimes used as livebait in the tuna fishery.

MAAREHI



English Name: Smoothbelly sardinella

Family: CLUPEIDAE

Local Name: Maarehi

Order: Clupeiformes

Size: Common to 15 cm; max. 23 cm

Specimen: MRS/0492/97

Distinctive Characters: Body moderately slender, belly rather rounded, scutes not prominent. 31-35 lower gill rakers on first gill arch. Pelvic fin with 8 rays. Last two anal fin rays enlarged. Fronto-parietal bones(on top of head) with 7-14 striations. Upper and lower bulges on supramaxillary bone symmetrical.

Colour: Back blue-green, flanks silvery and without spots. Dorsal fin dusky.

Habitat and Biology: Pelagic and usually inshore, forms schools in shallow coastal waters.

Distribution: Indo-West Pacific.

Remarks: Arnhlvgaster leiogaster does not appear to be especiallycommon in the Maldives, since this is the first record of its occurrence here. However, this may be due to the fact that it is not caught by the fishing gears normally used here. The specimen reported here was taken during experimental fishing carried by Marine Research Section using gillnets on 25th April 1996.

Kingdom:Animalia
Phylum:Chordata
Class:Actinopterygii
Order:Perciformes
Family:Scombridae
Genus:Thunnus
Species:T. obesus
The bigeye tuna, Thunnus obesus, is an important food fish and highly sought after recreational game fish. It is a member of the true tunas of the genus Thunnus, belonging to the wider mackerel family Scombridae.

Bigeye tuna are found in the open waters of all tropical and temperate oceans, but not the Mediterranean Sea. Its length is between 60 and 250 cm (23 and 93 inches). Maximum weight probably exceeds 400 lb with the all-tackle angling record standing at 392 lbs.

A longer-lived fish than the closely related yellowfin tuna, the bigeye tuna is thought to have a lifespan of up to 10 to 12 years, with individuals achieving sexual maturity at the age of four. Spawning has been recorded as taking place in June and July in the northwestern tropical Atlantic and in January and February in the Gulf of Guinea in the eastern Atlantic, which is, so far, the only known nursery area for Atlantic bigeye tuna.

Bigeye tuna are large deep-bodied streamlined fish with large heads and eyes. The pectoral fins are very long, reaching back as far as the second dorsal fin. There are 13 or 14 dorsal spines.

Body colour is dark metallic blue on the back with a grey-white belly and an iridescent blue band running along each flank. The dorsal and anal fins are yellow.

Bigeye tuna feed on a wide variety of fishes; cephalopods, mostly various squid species; and crustaceans during the day and at night. Feed items include both epipelagic and mesopelagic species, with deep diving behaviour during the day thought to be related to the seeking of prey.

Satellite tagging has shown that bigeye tuna often spend prolonged periods cruising deep below the surface during the daytime, sometimes making dives of deep as 500 metres. These movements are thought to be in response to the vertical migrations of prey organisms in the deep scattering layer. Physiological adaptations to foraging in these cold (bigeye tuna have been tracked entering water as cold as 5 degrees Celsius) and oxygen-poor subsurface waters include blood that is highly efficient in extracting oxygen from the water even in oxygen-poor conditions, and vision that is highly adapted for effective function in low light conditions. The heart of bigeye tuna also has an unusual ability to function effectively at the low ambient temperatures encountered while foraging in cold subsurface water. Nonetheless, bigeye tuna must make return trips to warmer surface waters to warm themselves up.

Bigeye tuna are amongst the tuna species most threatened by overfishing. Juvenile bigeye tuna associate closely with floating objects such as logs, buoys and other flotsam, which makes them extremely susceptible to purse seine fishing in conjunction with man-made FADs (Fish Aggregation Devices). Bigeye mature at a later age than other commercially important tuna species such as skipjack and yellowfin tuna, and the removal of large numbers of juvenile bigeye before they reach breeding age is a major concern to fisheries managers, scientists and sport fishermen.

Kingdom:Animalia
Phylum:Chordata
Class:Actinopterygii
Order:Perciformes
Family:Scombridae
Subfamily:Scombrinae
Genus:Auxis
Subspecies:A. thazard thazard
The frigate tuna or frigate mackerel, Auxis thazard thazard, is a subspecies of tuna, in the family Scombridae, found circumglobally in tropical oceans in open surface waters to depths of 50 m (164 ft). Its length is between 30 and 65 cm (12 and 26 in).

The frigate tuna is a comparatively small and slender tuna. It has a triangular first dorsal fin, widely separated from the second dorsal fin, which, like the anal and pectoral fins, is relatively small. There are the usual finlets of the tuna. There is a small corselet of small scales around the pectoral region of the body.

Frigate tunas are blue-black on the back with a pattern of zig-zag dark markings on the upper hind body, and silver-white below. The fins are dark grey.

They feed on small fish, squid, planktonic crustaceans, and stomatopod larva

Kingdom:Animalia
Phylum:Chordata
Class:Actinopterygii
Order:Perciformes
Family:Scombridae
Genus:Thunnus
Species:T. albacares
he yellowfin tuna (Thunnus albacares), is a type of tuna. It is found in open waters of tropical and subtropical seas worldwide. It is an epipelagic fish ranging in the top 100 m (330 feet) of the water column. Reported sizes have ranged as high as 239 cm (94 inches) in length and 200 kg (440 lb) in weight. Also known as ahi tuna, from its Hawaiian name ʻahi, yellowfin is becoming a popular replacement for the severely depleted supplies of bluefin tuna.

The second dorsal fin and the anal fin are both bright yellow, thus the common name, and can be very long in mature specimens, as are the pectoral fins. The main body is very dark metallic blue, changing to silver on the belly, which has about 20 vertical lines.

Yellowfins tend to school with fishes of the same size, including other species of tuna, and larger fish are often seen with dolphins, porpoises, whales and whale sharks. Yellowfins eat other fish, crustaceans, and squid.

Yellowfin tuna are a popular sport fish in many parts of their range and are prized for their speed and strength when fought on rod and reel as well as for their table qualities.

According to the Hawaii Seafood Buyers Guide 'Yellowfin tuna is widely used as raw fish dishes, especially sashimi. This fish is also excellent for grilling' [1] Yellowfin is often served seared or rare.

Yellowfin buyers often recognize two grades, "Sashimi grade" and "other", although there are variations in the quality of "other" grades.

Kingdom:Animalia
Phylum:Chordat
Class:Actinopterygii
Order:Perciformes
Family:Scombridae
Genus:Katsuwonus
Species:K. pelamis

The skipjack tuna, Katsuwonus pelamis, is a medium-sized perciform fish in the tuna family, Scombridae. It is otherwise known as the aku, arctic bonito, mushmouth, oceanic bonito, striped tuna, or victor fish. It grows up to 1 m (3.3 feet) in length.

It is a streamlined, fast-swimming pelagic fish, common in tropical waters throughout the world, where it inhabits surface waters in large shoals (up to 50,000 fish), feeding on fish, crustaceans, cephalopods and mollusks. It is an important prey species for large pelagic fishes and sharks.

It is an important commercial and game fish, usually caught using purse seine nets, and is sold fresh, frozen, canned, dried, salted, and smoked.

Carcharhinus albimarginatus (Ruppell, 1837)



English Name: Silvertip shark

Family: CARCHARHINIDAE

Local Name: Kattafulhi miyaru

Order: Carcharhiniformes

Size: Max, 3 m

Specimen: MRS/P031 1/88

Distinctive Characters: Snout moderatelylong and broadly rounded. Upperteeth broadly triangular. Second dorsal fin with a base less than twice height. Ridge between dorsal fins.

Colour: Grey above, pale below. First dorsal, pectoral, pelvic and caudal fins with extremely conspicuous white tips and posterior margins.

Habitat and Biology: Occurs inshore and offshore from the surface to a depth of 800 m. Feeds on both bottom and pelagic fish, including rays and cephalopods. Viviparous, with a yolk-sac placenta; number of
young 1 to 11 per litter, often 5 to 6.

Distribution: Tropical lndo-Pacific.

Remarks: Carcharhinus albimarginatus is said to be very aggressive and individuals often have evidence of combat scars. This shark is potentially dangerous to people. Rarely seen by divers in the Maldives,
although there have been regular sightings at two sites in An Atoll.

Hemipristis elongatus (Klunzinger, 1871)




English Name: Snaggletooth shark

Family: HEMIGALEIDAE

Local Name: Dhaiy bulhi miyaru

Order: Carcharhiniformes

Size: To at least 2.3 m; possibly to 2.4 m,

Distinctive Characters: Amedium-sized shark with blunt, rounded snout. Teeth absent at symphysis (midline)of lowerjaw. Lower teeth near symphysis long and strongly hooked. Upperteeth broad and curved with both
edges serrated. Gill openings long, the longest over three times eye length.

Colour: Grey; palerbelow.

Habitat and Biology: Occurs in coastal waters at depths up to 30 m. Feeds on inshore pelagic and bottom fishes. Viviparous with a yolk-sac placenta; 6-8 young per litter.

Distribution: Indo-West Pacific.

Remarks: Hemipristis c/ongatus appears to be rare in Maldives. The only known record so far is a set ofjaws seen on a R. Maduvari shark-netting dhoni operating in Haa Alifu Atoll. The jaws were saved by one of the
crew only because he had never seen this species before, This also appears to have been the first record from an oceanic island.

Mustelus manazo Bleeker, 1854




English Name: Starspotted smooth-hound shark

Family: TRIAKIDAE

Local Name: Hon’du miyaru

Order: Carcharhiniformes

Size: Max. about 1.2 m

Distinctive Characters: A small, slender shark with head somewhat flattened. Nasal flaps not reaching mouth. No nasal grooves. Mouth broadly angular. First dorsal fin large with origin in front of rear margin of pectorals. Second dorsal fin much larger than anal. Ridge between dorsals.

Colour: Uniform grey or grey-brown above, light below. A series of small white spots on sides.

Habitat and Biology: Bottom dwelling in continental waters. Commonly close inshore especially on mud and sandy bottoms. Feeds on small bottom fishes, molluscs and crustaceans. Ovoviviparous; number of young 1 to 22; increasing markedly with size of mother.

Distribution: Indian Ocean to Western North Pacific.

Remarks: Mustelus manazo in the Maldives is foundon outer atoll slopes in depths of 100-200 m. Specimens here lack the white spots typical of this species in other locations.