Stoloteuthis Verrill, 1881

Introduction

Stoloteuthis leucoptera, the best known species, is very common throughout the year in the Gulf of Maine at depths of 175 to 340 m. Only a few specimens have been taken on the outer shelf and slope south of Cape Cod although it is found as far south as the Straits of Florida. It has also been reported from the Mediterranean. This species, which reaches 25 mm ML, can be distinguished easily from all other neritic sepiolids in the western North Atlantic by the ventral shield of the mantle characteristic of all members of the Heteroteuthinae. Note the dramatic blue fringe to the shield in the title photograph and the silvery band of tissue around the mantle. Stoloteuthis is similar to Iridoteuthis but differs primarily in the presence of enlarged suckers on only the second arms in males and the absence of modified arm tips in females.

Diagnosis

A heteroteuthin ...

• with enlarged suckers on arms II of males.

Characteristics

1. Arms
   1. Arm suckers relatively larger in males but no arm asymmetry present; arms I in males with larger basal suckers than females (S. leucoptera at least).
   2. Arms II, in males, with enlarged suckers and one to several greatly enlarged.
      image info

      Figure. Oral view of brachial crown (minus tentacles) of S. maoria, mature male, off S.E. New Zealand (44°02'S, 178°08'W), otter trawl at 230-421 m. Drawing by A. Hart.

   3. Arm tips in females not modified.
2. Funnel
   1. Funnel locking-apparatus with straight, simple groove.
   image info
   image info

   Figure. Funnel/mantle locking-apparatus of S. leucoptera, 43°02'N, 69°04'W, NMNH 816246, left = anterior. Top - Side-oblique view of the mantle component. Bottom - Frontal view of the funnel component. Photographs by M. Vecchione.

3. Mantle
   1. Mantle fused to head dorsally; fusion narrower than head width.
   2. Ventral-mantle shield of mantle does not extend beyond middle of eyes.
4. Fins
   1. Fin margins rounded posteriorly.

Comments

S. weberi was formerly placed in Heteroteuthis. This species is reported to lack a dorsal head-mantle fusion, a feature that, if correct, would distinguish it from all other Stoloteuthis. The type specimen needs to be re-examined for this feature and the presence/absence of a nuchal cartilage. In most other features it resembles Stoloteuthis. S. maoria was formerly placed in Iridoteuthis. Harman and Seki (1990) re-examined S. maoria and found that it was similar to Iridoteuthis iris in its broad head-mantle fusion, middorsal mantle buldge and posteriorly pointed fins. We place S. maoria in Stoloteuthis on the basis of the arm modifications in mature members of both sexes which are similar to Stoloteuthis leucoptera.

Life History

image info

Figure. Dorsal and ventral views of young S. leucoptera, 9.8 mm ML. Drawings from Vecchione, et al. (2001).

Distribution

S. leucoptera is known from off the eastern United States and the Mediterranean Sea, S. weberi from Indonesia (7.6°S, 117.5°E) and S. maoria from off New Zealand. Unidentified species of Stoloteuthis have been reported from near the Kerguelens, Prince Edward Islands (southern Indian Ocean), Discovery Bank (Nesis, 1982/87).

References

Cairns, S. D. 1976. Biological results of the University of Miami deep-sea expeditions. 118. Cephalopods collected in the Straits of Florida by the R/V Gerda. Bull. Mar. Sci. 26: 233-272.

Nesis, K. N. 1982/87. 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.

Orsi Relini, L. and D. Massi. 1991. The butterfly squid Stoloteuthis leucoptera in the Mediterranean. J. Mar. Biol. Ass. U. K. 71: 47-51.

Vecchione, M., C. F. E. Roper and M. J. Sweeney. 1989. Marine flora and fauna of the eastern United States. Mollusca: Cephalopoda. NOAA Tech. Rep. NMFS 73: 23 pp.

Vecchione, M., C. F. E. Roper, M. J. Sweeney and C. C. Lu. 2001. Distribution, relative abundance and developmental morphology of paralarval cephalopods in the western North Atlantic Ocean. NOAA Tech Rep. NMFS 152.