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SCOMBR Euth 2
1983
FAO SPECIES IDENTIFICATION SHEETS
FAMILY: SCOMBRIDAE FISHING AREA 51 (W. Indian Ocean)
Euthynnus affinis (Cantor, 1849)
OTHER SCIENTIFIC NAMES STILL IN USE: Euthynnus yaito Kishinouye, 1915
VERNACULAR NAMES: pelvic FAO: En - Kawakawa fin Fr - Thonine orientale Sp - Bacoreta oriental NATIONAL:
interpelvic process DISTINCTIVE CHARACTERS:
A medium-sized fish with a robust, elongate and fusiform body. Teeth small and conical, in a single series; gillrakers 29 to 34 on first arch. Two dorsal fins, the first with 11 to 14 spines; both fins separated by only a narrow interspace (not wider than eye), anterior spines of first much higher than those mid-way, giving the fin a strongly concave outline; second dorsal fin much lower than first and followed by 8 to 10 finlets; pectoral fins short; never reaching the interspace between the dorsal fins; two flaps interpelvic process between pelvic fins; anal fin followed by 6 to 8 finlets. Body naked except for corselet and lateral line. A very slender caudal peduncle with a prominent lateral keel between 2 small keels at base of caudal fin. Colour: back dark blue with a complicated striped pattern which does not extend forward beyond middle of first dorsal fin; lower sides and belly silvery white; several characteristic dark spots between pelvic and pectoral fins (which, however, may not always be very conspicuous). DISTINGUISHING CHARACTERS OF SIMILAR SPECIES OCCURRING IN THE AREA:
Thunnus species, Allothunnus fallai and Gymno- sarda unicolor: no pattern of stripes on back; also, scales present on all parts of body in Thunnus:
Katsuwonus pelamis: no striped colour pattern on back, but very characteristic dark longitudinal bands along lower sides; also, more gillrakers on first arch (53 to 63; 29 to 34 in E. affinis).
Sarda species: mouth wider and upper jaw Katsuwonus pelamis reaching at least to hind margin of eye. Acanthocybium solandri and Scomberomorus species: body much more elongate; corselet of scales ill-defined; also, snout as long as rest of head, maxilla concealed, and vertical stripes on body in A. solandri. Grammatorcynus bilineatus: no stripes on body and 2 lateral lines. Sarda sp. Acanthocybium solandri Auxis, Scomber and Rastrelliger species: a large interspace between dorsal fins (at least equal to length of first dorsal fin base).
SIZE:
Maximum: about 100 cm; common to 60 cm.
Auxis thazard GEOGRAPHICAL DISTRIBUTION AND BEHAVIOUR:
Widespread along the entire east coast of Africa, in the Red Sea, the Gulf of Aden, the "Gulf", off Pakistan, in the west coast of India and Sri Lanka; eastward to Hawaii. Found in coastal waters and around offshore islands. Schools with other similar sized scombrids.
Feeds on small fishes, especially clupeoids and atherinids; also on squids, crustaceans and zooplankton.
FAO Species Synopses Nos 48 and 50 (as E. yaito), and 122.
PRESENT FISHING GROUNDS:
Coastal waters and around islands throughout its range.
CATCHES, FISHING GEAR AND FORMS OF UTILIZATION:
The catch from Fishing Area 51 totalled about 11 000 t in 1981, primarily by Pakistan.
Caught in multispecies fisheries, mainly by sur- face trolling; also with gillnets.
Marketed canned and frozen; also dried-salted and smoked.
SCOMBR Gram 1
1983 FAO SPECIES IDENTIFICATION SHEETS
FAMILY: SCOMBRIDAE FISHING AREA 51 (W. Indian Ocean)
Grammatorcynus bilineatus (Rüppell, 1836)
OTHER SCIENTIFIC NAMES STILL IN USE: Grammatorcynus bilineatus Gill, 1862 Nesagrammus piersoni Evermann & Seale, 1907
VERNACULAR NAMES:
FAO : En - Double-lined mackerel Fr - Thazard-kusara Sp - Carite cazón pintado
NATIONAL:
DISTINCTIVE CHARACTERS:
Body elongate, slightly compressed. Teeth slender and conical; rectangular patch of sharp teeth on tongue; gillrakers on first arch 19 to 24. Two dorsal fins separated by small interspace, the first with 11 to 13 spines, the second dorsal and anal followed by 6 or 7 finlets; pectoral fins short with 22 to 26 rays; a small single flap (inter- pelvic) process between pelvic fins. Two lateral lines, the lower pelvic fin joining the upper behind the pectoral fin base; and at the caudal fin base. Body covered with moderately small scales; no anterior corselet; caudal peduncle slender with a well developed lateral keel between the two smaller ones on each side.
Colour: back and upper sides metallic blue-green; lower sides interpelvic and belly silvery white. process DISTINGUISHING CHARACTERS OF SIMILAR SPECIES OCCURRING IN THE AREA:
Scomberomorus species: only one lateral line; teeth in jaws strong, compressed, triangular (slender and conical in Grammatorcy- no central keel nus); interpelvic process double (single in Grammatocynus); gill- rakers 3 to 16 in species in the area (19 to 24 in Glammatorcynus).
Scomber and Rastrelliger species: only one lateral line; no central keel between the 2 small keels on each side of caudal fin base; two dorsal fins are widely separated (close together in Glammatorcynus); adipose eyelids cover anterior and posterior edges caudal fin of eye (absent in Glammatorcynus). Scomber
adipose eyelid SIZE:
Maximum: 100 cm fork length; common to 40 cm.
GEOGRAPHICAL DISTRIBUTION AND BEHAVIOUR:
A tropical Indo-West Pacific species; reported from the Red Sea, Andaman Sea, coasts of Australia, Java Sea, Papua New Guinea, Celebes, the Philippines, Marshall Islands and the Ryuku Islands south of Japan. Scomber, Rastrelliger Found mainly around coral reefs. Forms large schools.
Feeds on fishes and crustaceans.
FAO Species Synopsis No. 72 (as G. bicarinatus).
PRESENT FISHING GROUNDS:
Surface waters, mainly near coral reefs.
CATCHES, FISHING GEAR AND FORMS OF UTILIZATION:
Separate statistics are not reported for this species.
Caught mainly by pole and line.
Marketed canned or frozen. The ammonia-like smell of the flesh can be masked by brushing with lemon juice prior to cooking. SCOMBR Gymno 1
1983 FAO SPECIES IDENTIFICATION SHEETS
FAMILY: SCOMBRIDAE FISHING AREA 51 (W. Indian Ocean)
Gymnosarda unicolor (Rüppell, 1838)
OTHER SCIENTIFIC NAMES STILL IN USE: Gymnosarda nuda (Günther, 1860)
VERNACULAR NAMES:
FAO : En - Dogtooth tuna Fr - Bonite à gros yeux Sp - Casarte ojón
NATIONAL:
DISTINCTIVE CHARACTERS:
Body elongate and moderately compressed. Mouth fairly large, upper jaw reaching to middle of eye; 14 to 31 large, conical teeth on upper jaw, 10 to 24 or lower jaw; 2 patches of teeth on upper surface of tongue; 11 to 14 gillrakers on first gill arch. Dorsal fins close together, the first (spiny) long (13 to 15 spines) its border almost straight, the second followed by 6 or 7 finlets; anal fin followed by 6 finlets; pectoral fins with 25 to 28 rays; interpelvic process large and single. Lateral line strongly undulating. Body naked posterior to corselet except for the lateral line, dorsal fin base, and caudal keel; caudal peduncle slender, with a well developed lateral keel between 2 smaller keels on each side. Colour: back and upper sides brilliant blue-black, lower sides and belly silvery; no lines, spots or other markings on body; anterior tip of first dorsal fin dark; other fins greysh. DISTINGUISHING CHARACTERS OF SIMILAR SPECIES OCCURRING IN THE AREA:
17 to longer Allothunnus fallai: first dorsal fin with more spines (15 to 18 spines against 13 to 15 in Gymno- sarda); interpelvic process small and bifid.
Sarda orientalis: 5 to 11 dark oblique stripes on back and upper sides; no teeth on tongue; first dorsal fin longer (17 to 19 instead of 13 to 15 in Gymnosarda unicolor). Sarda orientalis Thunnus species: body covered with very small scales behind corselet; teeth much smaller; border of spiny dorsal fin not straight; 2 flaps on interpelvic process.
Other species of Sco mbridae: various colour patterns of stripes, blotches or marblings.
SIZE: Thunnus tonggol Maximum: 110 cm fork length; common to 80 cm. pelvic fins
GEOGRAPHICAL DISTRIBUTION AND BEHAVIOUR:
A tropical Indo-West Pacific species; pro- bably throughout the Western Indian Ocean, actually recorded from Tanzania, Madagascar, Reunion, Maurit,us, Rodrigues, Comoro Islands, Aldabra, interpelvic interpelvic process Amirante Islands, Seychelles Islands, the Red Sea, process the Laccadive Archipelago, the Maldive Islands, and Sri Lanka. Thunnus Gymnosarda An offshore species found mainly around coral reefs. Usually solitary.
Feeds mostly on small schooling fishes and squids.
FAO Species Synopsis No. 75.
PRESENT FISHING GROUNDS:
Surface waters, mainly near coral reefs.
CATCHES, FISHING GEAR AND FORMS OF UTILIZATION:
Separate statistics are not reported for this species.
Caught mainly by pole and line.
Marketed canned or frozen.
SCOMBR Kats 1
1983
FAO SPECIES IDENTIFICATION SHEETS
FAMILY: SCOMBRIDAE FISHING AREA 51 (W. Indian Ocean)
Katsuwonus pelamis (Linnaeus, 1758)
OTHER SCIENTIFIC NAMES STILL IN USE: Euthynnus pelamis (Linnaeus, 1758)
VERNACULAR NAMES:
FAO : En - Skipjack tuna Fr - Bonite à ventre rayé (= Listao, Fishing Area 31) Sp - Listado
NATIONAL:
DISTINCTIVE CHARACTERS:
Body fusiform, elongate and rounded. Teeth small and conical, in a single series; gillrakers numerous, 53 to 63 on first gill arch. Two dorsal fins pelvic fin separated by a small interspace (not larger than eye), the first with 14 to 16 spines, the second followed by 7 to 9 finlets; pectoral fins short, with 26 or 27 rays; 2 flaps (interpelvic process) between pelvic fins; anal fin followed by 7 or 8 finlets. Body scaleless except for the corselet and lateral line. A strong keel on each side of base of caudal fin between 2 smaller keels.
Colour: back dark purplish blue, lower sides and belly silvery, with 4 to interpelvic 6 very conspicuous longitudinal dark bands which in live specimens may appear process as discontinuous lines of dark blotches. DISTINGUISHING CHARACTERS OF SIMILAR SPECIES OCCURRING IN THE AREA:
Sarda orientalis is the only other species in the area with longitudinal stripes but these are on the back instead of on the belly as in K. pelamis. S. orientalis also has fewer gillrakers (16 to 22 instead of 53 to 63) and more spines in the long, low and straight first dorsal fin (17 to 19 instead of 14 to 16). All other scombrid species in the area lack the dark longitudinal bands on lower flanks, and have fewer gillrakers, at most 40 (Thunnus maccoyii). Sarda orientalis
SIZE: Maximum: 100 cm fork length; common to 80 cm.
GEOGRAPHICAL DISTRIBUTION AND BEHAVIOUR:
Cosmopolitan in tropical and subtropical seas. Found from the Cape Peninsula of South Africa, off the coast of East Africa including Madagascar, Réunion, Mauritius, Aldabra, and the Seychelles, in the Red Sea, the Gulf of Aden, the Laccadive Sea, the Maldives, the Indian coast and Sri Lanka; apparently absent from the "Gulf". Occurs in large schools in oceanic waters, gene- rally above the thermocline.
Feeds on fishes, cephalopods, and crustaceans.
FAO Species Synopses Nos 64 and 136 (and Nos 58 - Atlantic and Mediterranean, 65 - Pacific).
PRESENT FISHING GROUNDS:
Deep coastal and oceanic waters.
CATCHES, FISHING GEAR AND FORMS OF UTILIZATION: The catch from Fishing Area 51 totalled about 35 000 t in 1981 primarily by the Maldives and Sri Lanka. Caught mainly with purse seines; also by pole and line. Also an important game fish usually taken by trolling on light tackle using plugs, spoons, feathers, or strip bait.
Marketed canned or frozen.
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