Ancistrocheirus lesueurii (Orbigny 1842)

Although only a single species is recognized in the Ancistroceiridae, differences in paralarval morphology between Atlantic and Pacific specimens suggest that more than one species exists (Young, et al., 1992).

Introduction

Ancistrocheirus lesueurii is of moderate size (25 cm ML) and occupies tropical and subtropical waters of the world's oceans at mesopelagic depths. Adults may be associated with the ocean floor over the slope (Nesis, 1982/7). They bear hooks on the arms and tentacles and have large sagittate fins. Photophores have a distinctive arrangement and appearance. Those on the ventral surface of the head and mantle occur in two very different size catagories.

Diagnosis

An oegopsid squid ...

• with numerous, small integumental photophores, including photophores on the tentacles but without photophores on the eyeballs or viscera.

Characteristics

1. Buccal crown
   1. Buccal membrane pigmented.
2. Photophores
   1. Photophores on head and mantle in two distinct size classes.
   2. Generally 22 large photophores on ventral surface of mantle arranged in fixed pattern of twos and fours as follows: 4+2+4+2+4+2+4.
   3. Large photophores on head, funnel, base of arms II and tentacular stalk.
   4. Numerous very small photophores on fins, mantle, funnel, head and arms IV.
   5. No photophores on eyeballs or viscera.
   6. Additional photophores present in mature squid: Mature males with large, lidded, elongate photophores on aboral tips of arms IV; mature females with apparent photophores on tips of dorsal six arms
3. Mantle and fins
   1. Fins slightly subterminal.
   2. Tail fleshy, large; vesicles absent.
   3. Gladius with long pointed rostrum.
4. Head, arms, and tentacles
   1. Nuchal folds present.
   2. Hooks present on all arms.
   3. Tentacular clubs with hooks in two series on manus; suckers absent from manus; dactylus reduced.
      image info image info
   4. Tentacles not modified near base; stalk "ligament" and vein leave tentacle at base and in a membrane.
5. Internal anatomy
   1. Nidamental glands present.
   2. Oviducal glands normal.
   3. Oviducts equally developed.

Comments

Nomenclature

Orbigny (1834-48) described Enoploteuthis lesueurii in 1842 from the Indian Ocean, and Gray (1849) designated it the type species of his genus Ancistrocheirus. In 1851, Verany described Loligo alessandrinii from off Messina, Mediterranean; it was first placed in Calliteuthis Verrill, 1880 by Appellof (1890), then Pfeffer in 1900 reassigned it to his new genus Thelidioteuthis. Subsequently both genera and their species were synonomyzed (Nesis, 1978). The Enoploteuthidae, Pyroteuthidae and Ancistrocheiridae generally, have been considered subfamilies of the Enoploteuthidae. Clarke (1988) raised each subfamily to familial status and Young and Harman (1998) provided cladistic support for this arrangement.

A list of all nominal genera and species in the Ancistrocheiridae can be found here. The list includes the current status and type species of all genera, and the current status, type repository and type locality of all species and all pertinent references.

Life History

Distristribution

Insufficient material has been available for critical species-level comparisons of specimens from different regions.

References

Appellof, A. 1890. Teuthologische Beitrage I. Ctenopteryx n.g., Veranya sicula Krohn, Calliteuthis Verrill. Bergens Museums Aarsbertning, 1889(3):1-34.

Clarke, M.R. 1988. Evolution of Recent Cephalopods - A Brief Review. pp. 331-340. In: M.R. Clarke and E.R. Trueman, (eds.), The Mollusca, Vol. 12, Paleontology and Neontology of Cephalopods. Academic Press.

Gray, J.E. 1849. Catalogue of the Mollusca in the Collection of the British Museum, Part I. "Cephalopoda Antepedia". London, British Museum (Nat. Hist.), 164 pages.

Nesis, K. N. 1978. The subfamily Ancistrocheirinae (Enoploteuthidae). Zoologichesky Zhurnal, 57(3):446-449. (In Russian, English summary).

Nesis, K. N. 1982. Abridged key to the cephalopod mollusks of the world's ocean. 385+ii pp. Light and Food Industry Publishing House, Moscow. (In Russian.). Translated into English by B. S. Levitov, ed. by L. A. Burgess (1987), Cephalopods of the world. T. F. H. Publications, Neptune City, NJ, 351pp.

Okutani, T. 1974. Epipelagic decapod cephalopods collected by micronekton tows during the EASTROPAC expeditions, 1967-1968 (systematic part). Bull. Tokai Reg. Fish. Res. Lab., 80: 29-118.

Orbigny, A.d' 1834-48. In A. d'Ferussac and A. d'Orbigny, A., 1834-1848. Histoire Naturelle Generale et Particuliere Cephalopodes Acetabulifäres Vivants et Fossiles, J.B. Bailliere, Paris, 96 pages + LVI + 361 pages. Atlas of 144 plates.

Pfeffer, G. 1900. Synopsis der oegopsiden Cephalopoden. Jahrbuch der Hamburgischen Wissenschafthchen Anstalten, 17(2):147-198.

Verany, J.B. 1851. Cephalopodes de la Mediterranee. Mollusques Mediterraneens Observes, Decrits, Figures et Chromolithographies d'gores le vivant ouvrage dedii ASM le roi Charles Albert, I:1-132, 41 plates.

Young, R. E., L. A. Burgess, C. F. E. Roper, M. J. Sweeney and S. J. Stephen. 1998. Classification of the Enoploteuthidae, Pyroteuthidae and Ancistrocheiridae. Smithsonian Contr. to Zoology, 586: 239-255.

Young, R. E. and R. Harman. 1998. The phylogeny of the "enoploteuthid families." Smithson. Contr. Zool., No. 586: 257-270.