European squid swim backwards. They have two sidelong fins on the hind part of their body, giving them an arrow-like appearance. In Dutch, they are appropriately called 'arrow' squid. Like all cuttlefish, squid have highly developed eyes which they use to hunt. When chasing a school of fish, they rapidly swim backwards through the school, turning suddenly on their side to grab a fish. The cords of eggs are found on the beaches in June. There's a good chance to even see young squid in the eggs! Adult European squid do not generally come close to the coast, and therefore do not often wash ashore. However, you can find their elongated cuttlebone, which looks like a hard transparent piece of plastic.

Loligo species are the common inshore squids of the eastern Atlantic Ocean. Several species are targets of substantial fisheries. Although the biology of some species of Loligo (e.g., L. vulgaris, L. reynaudii ) is among the best known of any cephalopod, considerable controversy remains about their taxonomy and systematic relationships.

The genus is defined by geography and the absence of specific modifications that define other genera.

Brief diagnosis:

A loliginid ...

• with rhomboidal fins in adults, longer than broad (length <70% of ML); mantle elongate; without photophores.
• with an Eastern Atlantic distribution.

According to Lesueur (1821), use of the name "loligo" for squids can be traced to the classical Roman philosopher, Pliny (lib. IV, cap. XIX; see also Naef, 1923:197). Linnaeus established Sepia loligo in 1758 to encompass all cephalopods with a cylindrical body and fins (Hoyle, 1910:410). Subsequently, squids in general were often referred to as "loligos" (e.g. Lesueur, 1821). Many authors have interpreted Schneider's (1784) use of the name "Loligo" (capitalized and not preceded by a generic name) as the establishment of the genus Loligo. However, Hemming (1954) showed that Loligo Schneider, 1784 resulted from a misinterpretation of Schneider's work. Schneider's intent was to remove Nautilus Linnaeus, 1758 and Argonauta Linnaeus, 1758 from the univalve molluscs and to include them with all other cephalopods in a new genus, Octopodia. Thus, Schneider actually proposed the new combination Octopodia loligo but did not follow the convention of always using the generic name and not capitalizing the species. Loligo was then formally described by Lamarck in 1798 to distinguish four squid species, L. vulgaris, L. subulata, L. sagittata and L. sepiola from the octopods (for which he erected the genus Octopus Lamarck, 1798) and from the cuttlefishes of the genus Sepia.

The only other squid genera that predate 1821 are Onychoteuthis Lichtenstein, 1818, which was established to distinguish cephalopods in which hooks replace some of the suckers on the arms or tentacles, and Cranchia Leach, 1817, a very unusual squid.

1. Arms
   1. Hectocotylus
      1. Ventral crest absent.
      2. Proximal suckers unmodified.
      3. Modified suckers of reduced size and sucker stalks elongated to form papillae in either dorsal or both dorsal and ventral series.
         
         
2. Tentacles
   1. Tentacular clubs expanded; suckers in four series.
      
      
3. Mantle
   1. Elongate, posterior tip blunt.
      
      
4. Fins
   1. Fins in adults rhomboidal and longer than broad, tapering posteriorly.
   2. Fins extend to posterior tip of mantle.
      

      Figure. Ventral view of a mature male of L. vulgaris. Drawing from Naef (1921-3).

5. Photophores
1. Photophores absent.
   
   
6. Viscera
   1. Eggs less than 4 mm.
   2. Spermatophore cement body short.

Comments:

Alloteuthis is morphologically very similar to Loligo. However, molecular analyses by Anderson (2000) indicate that Alloteuthis should be considered a separate genus. This supports earlier inferences by Naef (1921-23) and Alexeyev (1989) that the presence of a gladial conus in Alloteuthis should be considered a generic character. The conus in Alloteuthis would clearly separate the genera but it can be very difficult to find and in some Alloteuthis specimens may be reduced until it is essentially absent. The posterior tip of the mantle in Alloteuthis is elongate into a tail-like structure that tends to be more pointed than in Loligo. This is particularly true for males but identification of this character state can be subjective in females.

Loligo includes species of the eastern Atlantic Ocean and forms a nearly continuous distribution from southern Africa to 60°N.

Depth range based on 38709 specimens in 29 taxa.
Water temperature and chemistry ranges based on 23204 samples.

Environmental ranges
  Depth range (m): -9 - 735
  Temperature range (°C): 2.696 - 27.637
  Nitrate (umol/L): 0.167 - 30.351
  Salinity (PPS): 31.893 - 38.792
  Oxygen (ml/l): 2.469 - 7.464
  Phosphate (umol/l): 0.019 - 2.595
  Silicate (umol/l): 0.498 - 46.900

Graphical representation

Depth range (m): -9 - 735

Temperature range (°C): 2.696 - 27.637

Nitrate (umol/L): 0.167 - 30.351

Salinity (PPS): 31.893 - 38.792

Oxygen (ml/l): 2.469 - 7.464

Phosphate (umol/l): 0.019 - 2.595

Silicate (umol/l): 0.498 - 46.900
 
Note: this information has not been validated. Check this *note*. Your feedback is most welcome.

Loligo is prey of:
Pomatomus

Based on studies in:
USA: Massachusetts, Cape Ann (Marine, Sublittoral)

This list may not be complete but is based on published studies.

Loligo preys on:
Fundulus

Based on studies in:
USA: Massachusetts, Cape Ann (Marine, Sublittoral)

This list may not be complete but is based on published studies.

View Loligo Tree

Type species.-- Loligo vulgaris Lamarck, 1798, by subsequent designation of Hoyle (1910).

Except for geographic distribution, Loligo species are unified in their lack of the characters distinctive of some other genera (photophores, spermatophore with long cement body, large eggs, hectocotylus with ventral crest, etc.). The most distinct of the three species is L. forbesi. The southern African species, L. reynaudii, is very similar to L. vulgaris and , based on electrophoresis, Augustyn and Grant (1988) concluded that L. reynaudii should be considered a subspecies of L. vulgaris. However, L. reynaudii and L. vulgaris are allopatric and distinct morphologically; we consider them to be distinct species.

Barcode of Life Data Systems (BOLD) Stats
                                        

Specimen Records:	127	Public Records:	78
Specimens with Sequences:	111	Public Species:	10
Specimens with Barcodes:	106	Public BINs:	8
Species:	12
Species With Barcodes:	10

Access Published & Released Data: Download FASTA File

Collection Sites: world map showing specimen collection locations for Loligo