''Afrololigo mercatoris'', commonly known as the Guinean thumbstall squid, is a small species of

squid True squid are molluscs with an elongated soft body, large eyes, eight arms, and two tentacles in the superorder Decapodiformes, though many other molluscs within the broader Neocoleoidea are also called squid despite not strictly fitting t ...

in the

family Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...

Loliginidae Loliginidae, commonly known as pencil squids, is an aquatic family of squid classified in the order Myopsida. Taxonomy The family Loliginidae was formerly classified in the order Teuthida. Taxonomic list The classification below follows V ...

from the eastern central Atlantic Ocean. It is the only species in the monotypic genus ''Afrololigo''.

Description

''Afrololigo mercatoris'' is a relatively small species of squid where the females reach a

mantle A mantle is a piece of clothing, a type of cloak. Several other meanings are derived from that. Mantle may refer to: *Mantle (clothing), a cloak-like garment worn mainly by women as fashionable outerwear **Mantle (vesture), an Eastern Orthodox ve ...

length of 50mm and the males attain 35mm. Its mantle is wide, the width being equal to around 35% of the length of the mantle, and blunt at the posterior end. It has short, round fins, equalling 40-45% of the length of the mantle and between 55% and 65% of mantle length in width, with a convex margin at the rear. The head is short and the short and there are no buccal suckers on the buccal lappets. The

tentacular club All cephalopods possess flexible limbs extending from their heads and surrounding their beaks. These appendages, which function as muscular hydrostats, have been variously termed arms, legs or tentacles. Description In the scientific li ...

is small and narrow with suckers which are set out in 4 longitudinal series, 4 or 5 pairs of medial suckers on the central part of the club, the manus which are enlarged when compared to the lateral suckers. The club suckers have rings of 15 to 25 sharp teeth which become more pointed and increase in size towards the tip. Its dorsal arms are very short in comparison with its other arms and in males the left ventral arm is hectocotylized. The arm has 6 to 12 pairs of normal suckers at its base with the suckers replaced towards the tip by elongate papillae, these are more strongly developed in the dorsal row.

Distribution and ecology

''Afrololigo mercatoris'' occurs only off the west coast of Africa from Rio de Oro in Mauritania) to

Lüderitz Bay Lüderitz Bay or Lüderitzbaai (german: Lüderitzbucht), also known as Angra Pequena (, "small cove"), is a bay in the coast of Namibia, Africa. The city of Lüderitz is located at the edge of the bay. Geography The bay is indented and comple ...

in Namibia. This species is collected from depths of less than 50 m where there are mud and sandy-mud substrates. There is very little data available on its life cycle and biology. The eggs are small and the

spermatophore A spermatophore or sperm ampulla is a capsule or mass containing spermatozoa created by males of various animal species, especially salamanders and arthropods, and transferred in entirety to the female's ovipore during reproduction. Spermatophores ...

s have long bodies made of cement. This species is not a species of interest to fisheries.

Taxonomy

''Afrololigo mercatoris'' shows some morphological similarity with the squids of the genus '' Lolliguncula'', which is where William Adam originbally placed it when he described this species. However, based on morphology, genetic data and distribution ''Afrololigo''was recognised as a distinct

monotypic In biology, a monotypic taxon is a taxonomic group (taxon) that contains only one immediately subordinate taxon. A monotypic species is one that does not include subspecies or smaller, infraspecific taxa. In the case of genera, the term "unispec ...

genus. The

Red Sea The Red Sea ( ar, البحر الأحمر - بحر القلزم, translit=Modern: al-Baḥr al-ʾAḥmar, Medieval: Baḥr al-Qulzum; or ; Coptic: ⲫⲓⲟⲙ ⲛ̀ϩⲁϩ ''Phiom Enhah'' or ⲫⲓⲟⲙ ⲛ̀ϣⲁⲣⲓ ''Phiom ǹšari''; T ...

species ''

Uroteuthis abulati ''Uroteuthis'' is a genus of 14 species of common inshore squids of the Indo-West Pacific and is further subdivided into 3 subgenera. The members of the genus ''Uroteuthis'' are the only squids of the family Loliginidae that possess photophores ...

'' was also thought to be close to ''A. mercatoris''.

References

{{Taxonbar, from=Q18586880 Squid Cephalopod genera Monotypic mollusc genera Molluscs described in 1941