Northern Shortfin Squid

Mantle robust, widest at midpoint between anterior end and beginning of fins; tail not sharply pointed. Fin angle moderate, 40° to 50° mostly 45° ; fin width greater than fin length. Head small, short and narrow. Arms relatively short, of about equal length in both sexes; hectocotylized arm (in males) shorter than the opposite ventral arm (IV), its modified portion very short, about 22% of arm length; trabeculae (lamellae) without papillose fringed flaps; 1 or 2 knobs on dorsal row of lamellae on modified arm tip. Colour: reddish-brown to deep purple, more intense on head, arms and dorsal surface of mantle and fins; paler on ventral surfaces; a brilliant yellowish-green tint.

Western Atlantic: 25°N to 60°N. Northern and eastern Atlantic: British isles north to Iceland and Greenland.

Maximum mantle length 31 cm in females, 27 cm in males in the northern part of its distributional range, but 20 cm in females and 18 cm in males in the southern part.

An oceanic and neritic species,its total depth range extends from the surface to about 1000 m, but varies seasonally.In the western Atlantic, seasonal northward - inshore and southward - offshore migrations take place in correlation with environmental conditions, feeding and reproductive cycles. Two groups of spawners one in spring/summer and the other in autumn/winter can be distinguished. Spawning apparently takes place offshore in deeper waters. Females produce large, spherical, gelatinous egg masses that may reach 1 mm in diameter containing up to 100 000 eggs. Post-spawning, mortality is very high. Fertilization of eggs is more efficient at higher temperatures (range 7 to 21° C). Eggs require temperatures between 12 and 22° C for complete development. Hatching occurs after 9, 13 or 16 days at temperatures of 21°,16° and 13° C respectively. Larvae hatching from the winter brood between January and February grow to adult size in little more than 1 year, and spawn after approximately 18 months in summer. Summer hatchlings achieve a mantle length of about 18 or 19 cm after 1 year (females are slightly larger than males) and are ready to spawn in winter at an age of about 1 ½ years (Mesnil, 1977). Growth rates vary directly with temperature and inversely with size.Small-sized northern shortfin squids feed mainly on euphausids (Meganyctiphanes and Thysanoessa but switch to finfishes (capelin, herring, and juvenile mackerel) as they grow larger. Squid bites may render unsaleable the finfish part of mixed trawl catches.Squids are in turn preyed upon by cod, adult mackerel, pilot whales and dolphins.

This species is almost exclusively fished in the northwestern Atlantic. Catches deteriorated from a 1979 peak of almost 180 000 t to only about 38 000 t in 1981 (FAO, 1983). Two large international fisheries exist: one in the bays of Newfoundland using jigs and jigging machines in depths from 0 to 30 m, and occasionally otter trawls (during summer and early autumn); and an extensive otter trawl fishery along part of eastern Canada and the USA on the shelf and upper slope, and around submarine canyons in depths from 100 to 250 m. Japan and Canada are the two countries taking the greatest share of these catches. The species is in high demand as bait in the autumn cod fishery off Newfoundland because it does not soak and fall off the hooks as fast as finfish bait. Its flesh is also of good food quality although it is high in water content and deteriorates easily. It is therefore processed (but not as salted-fermented 'siokara') or sold immediately fresh. It commands a price approximately 60% of that for Todarodes pacificus .The total catch reported for this species to FAO for 1999 was 7 950 t. The countries with the largest catches were USA (7 334 t) and Canada (313 t).

Illex illecebrosus (Lesueur, 1821)

DIAGNOSIS.—Hectocotylus (see Figure 1) with distal hectocotylized portion of arm IV (HA3) limited to about 22% (13%–30%) of total arm length (HALt); papillae and lamellae weakly developed; basal, suckerless part (HAb) of hectocotylized arm short, about 6% of total arm length; proximal sucker-bearing part (HA1) with 7 to 8 pairs of normal suckers increasing in diameter distally; distal sucker-bearing part (HA2) with slight secondary modification of reduction in sucker diameter compared to normal proximal suckers; oral surface of arm IV not expanded, sucker rows not abnormally separated; very slight muscular constriction in transition zone between proximal (HA1) and distal (HA2) sucker-bearing parts; trabeculae not modified as fringed lobes; hectocotylized arm shorter than or equal to its opposite arm in length and always equal in thickness. Club expanded; largest distal medial manal sucker rings smooth, without crenulations or notches. Head-width index low, 16.3–17.0. Lower beak with jaw edge straight, short; wing long, wide, no lobe; rostral width narrow; lateral wall short, blunt. Upper beak with hood long, strong; shoulder serrated; rostrum long; wing short; jaw angle with large notch, with tooth; lateral wall short, shallow; crest curved. Fin angle mostly 45° (40°–50°), never > 50°. Spermatophore cone at oral end of cement body, a low, right-isosceles triangle with rounded corners in outline; oral tube long, narrow; aboral neck long, narrow.

ORIGINAL DESCRIPTION.—Lesueur, 1821:95.

TYPE LOCALITY.—Sandy Bay, Massachusetts, United States.

TYPE.—No types were designated. The single specimen illustrated by Lesueur when he caught it at Sandy Bay would have been the holotype (1821:95), but that specimen was not retained according to Lesueur. Based on Lesueur's description and comments, this appears to have been the only specimen available. Extensive searches (individually by CCL, CFER, and G.L. Voss) at the Academy of Natural Sciences, Philadelphia, other museums in the United States, and the Museum National d'Histoire Naturelle, Paris, confirm that no specimen in any way applicable as a holotype or as a neotype is extant.

DESIGNATION OF NEOTYPE.—In the absence of any original type material, and because of exceptional circumstances described below, it is necessary to designate a neotype as follows: mature male, 199 mm ML, National Museum of Natural History, Smithsonian Institution, USNM 727456, Figure 2; measurements, indices, and counts of the neotype are given in Table 1.

Character Measurement (mm) Index (%)

ML 199

VML 188 94.5

HL 34.4 17.3

HW 27.5 13.8

MW1 30.8 15.5

MW2 35 17.6

MW3 18.6 9.4

FL 85 42.7

FW 111 55.8

FbL 76 38.2

AL,I 74 37.2

AL,II 95 47.7

AL,III 94 47.2

AL,IV 85 42.7

HALt* 88 44.2

HAb 8 9

HA1 28 32

HA2 35 40

HA3 17 19

CL 49 24.6

AS,I 2.6 1.31

AS,II 4.0 2.01

AS,III 3.9 1.96

AS,IV 2.1 1.06

CIS 2.8 1.41

GL 65 32.7

SpL 21 10.6

SpRL 14.5 69.1

SpRW 0.3 1.43

CBL 2.8 13.3

FA 41°

ASC,I 102

ASC,II 100

ASC,III 98

ASC,IV 119

GiLC 69

*Right arm IV hectocotylized.

The International Commission on Zoological Nomenclature (ICZN) (Art. 75(b), 1985:157) stipulates that a neotype can be designated “only in exceptional circumstances…in the interests of stability of nomenclature.” In the case of I. illecebrosus, the exceptional circumstances occurred with the simultaneous description of I. oxygonius and the recognition of this new species and I. coindetii as sympatric with I. illecebrosus in the western North Atlantic (Roper et al., 1969). The range of interand intraspecific variability of characters makes species identification very difficult. A major international fishery exists for I. illecebrosus in the north, and it extends southward into the area of sympatry off the mid-Atlantic States. Consequently, all three species are involved in the fishery in the area of sympatry. Any type of rational exploitation and management plan must take into account the three very similar species. The designation of clearly defined neotypes for Illex illecebrosus and I. coindetii (see below) therefore is necessary for nomenclatural stability.

NEOTYPE LOCALITY.—Old Scantum grounds, 12–16 km (8–10 miles) southeast of the Isles of Shoals, New Hampshire, United States, southwest edge of Jeffery's Basin, approximately 43°N, 70°30′W, 17-VIII-1971; otter trawl at 117 m; fishing vessel Osprey, Capt. R.A. Stetson, Rye, New Hampshire; collected by C.F.E. Roper. This locality is about 34 km north of Sandy Bay, Massachusetts, Lesueur's type locality.

GEOGRAPHICAL DISTRIBUTION.—Western North Atlantic Ocean from 66°N (Iceland, southern Greenland, Baffin Island) southward to around 29°N in the Straits of Florida (Figure 3). Illex illecebrosus is a primarily neritic species that normally inhabits continental shelf and upper slope waters.

Illex illecebrosus, commonly known as the northern shortfin squid, is a species of neritic squids in the family Ommastrephidae. Squids of the genus Illex account for 65% of the world’s cephalopod captures. Illex is formed by four taxa distributed throughout the Atlantic Ocean (I. argentinus, I. coindetii, I. illecebrosus and I. oxygonius), whose identification and phylogenetic relationships based on morphological characters remain controversial.They are found in the northwest Atlantic Ocean, from off the coast of eastern North America to Greenland, Iceland, and west of Ireland and the United Kingdom. They are a highly migratory and short-lived species, with lifespans of less than a year. They are commercially important and are fished extensively (primarily by the United States and Canada), mostly for the Canadian and Japanese markets. Northern shortfin squid is a migratory species of squid with a distribution ranging from Florida Straits to Newfoundland in the Northwest Atlantic Ocean. The species is native to Canada, Greenland, Iceland and United States. The species has an average lifespan between 1–1.5 years in which most live less than a year. The location of the fishery of the squid is mainly in Mid-Atlantic Bight from between summer and fall.

fish, crustaceans, and smaller squid

western Atlantic from the Straits of Florida to Greenland and Iceland and extends eastward to the British Isles

neritic to oceanic, epi- to mesopelagic

epipelagic