Loligo vulgaris Lamarck 1798

Introduction

Characteristics

1. Mantle
   1. Mantle long, moderately slender, cylindrical.
2. Fins
   1. Fins rhomboid, their length two thirds of mantle length, posterior border slightly concave.
3. Arms:
   1. arm sucker rings with 20 teeth, distal teeth large and pointed, proximal teeth minute or absent.
   2. Left ventral arm hectocotylized along its distal 1/3 - 2/4 by modification of suckers into papillae that decrease in size distally
4. Tentacles
   1. Manus of tentacular clubs with 4 longitudinal series of suckers, 2 median series with 6 enlarged suckers each.
   2. sucker rings of median series on manus with approximately 30 irregularly-sized teeth; club with about 36 transverse rows of minute suckers.

Habitat and biology

Ranging in depth from the surface to approximately 500 m, and most abundant between 20 and 250 m; deepest in winter. European squid is known to migrate vertically and horizontally in response to changes in environmental conditions. The stock in the northeastern Atlantic overwinters in deeper waters off Portugal, approaches the French coast in spring, and migrates from May through June farther north into the North Sea where spawning takes place in depths from 20 to 80 m. A southward migration takes place in fall. The stock on the west Saharan fishing grounds likewise overwinters in deeper offshore waters and migrates onshore for spawning in spring and fall. Accordingly, juveniles appear to recruit into the fishery in February and March and between July and September. In the western Mediterranean, European squid migrate into deeper water in late fall; the largest individuals begin their onshore migration as early as in January and February, followed in summer by the smaller ones.

Spawning extends for most of the year with peaks in early summer and early fall. Females produce up to 20000 small eggs (diameter about 2 mm) that are deposited in gelatinous tubes containing tens of eggs and attached to debris and other hard objects on sandy to muddy bottoms. The eggs hatch after an incubation period ranging between 25 days (at 22° C) and 45 days (at 12 to 14°C). The number (up to 800) and size of spermatophores is directly related to the size of the male. Males reproducing for the second time usually carry more than those reproducing for the first time.

Growth is faster in summer than in winter in both sexes; the rate is greater in males as compared with females. In the Atlantic, June hatchlings attain approximately 12 cm mantle length in December and 13 or 14 cm in the following April. By August, males reach about 17.5 cm and in April of their second year 21 cm, compared to 17 cm in females. In the western Mediterranean, juvenile females and males migrating onshore in July measure about 7 and 8 cm respectively (ranges 6.6 to 8 cm, and 7 to 8.3 cm) and grow to about 15 and 16 cm in December (ranges 14 to 16 cm and 15 to 17 cm). On the other hand, juveniles approaching the coast in October are approximately 5.7 cm long (range 5 to 6.3 cm) growing to 8.3 cm (range 7.8 to 8.9 cm) towards the end of December when they leave the shallow waters. By March they have attained a length of 13 cm. After May they mix with the other group in a new onshore migration to where spawning occurs.

Longevity is 2 years in females and about 3 years in males.

European squid feed on fishes and crustaceans. Cannibalism is common.

Geographical distribution

Remarks

Loligo reynaudi has previously been proposed to be a subspecies of L. vulgaris.

Other Names for Loligo vulgaris Lamarck 1798

• European squid
• Vernacular Names: En: European squid, Fr: Encornet, Sp: Calamar