Cirroteuthidae Keferstein 1866

Introduction

Species in the family are entirely pelagic and have a very fragile, gelatinous structure and eyes that vary from large to small to degenerate. They are usually found in association with the ocean floor (benthopelagic) at great depths. Some have, however, been caught far above the bottom and one specimen was dip-netted through an ice hole in the Arctic.

Diagnosis

A cirrate ...

• with long cirri and secondary webs.
• with saddle-shaped shell.
• with anterior mantle attached dorsally to head. 

Characteristics

1. Shape and consistency
   1. Anterior-posteriorly elongation pronounced.
      
      
2. Web
   1. Primary and secondary webs present.
   2. Web nodules present or absent. image info

      Figure. Oral view of left arm III of Cirroteuthis muelleri. Drawing modified from Voss and Pearcy, 1990.

3. Cirri
   1. Very long: Longest more than 8 times largest sucker diameter.
      
      
4. Suckers
   1. Central portion of each arm with small, flattened suckers, nearly lacking acetabulum (i.e., aperatures may be virtually absent), on stalks that are either slender or swollen and fluid-filled.
      
      
5. Gills
   1. Sepioid
      
      
6. Digestive system
   1. Digestive tract arranged in simple U-shape; intestine short, without lateral bends
   2. Posterior salivary glands present on buccal mass.
   3. Radula present or absent.
   4. Digestive gland unilobular.
      
      
7. Reproductive system.
   1. Male accessory gland complex compacted into a single mass.
      
      
8. Optic lobe
   1. Spherical.
   2. Single optic nerve bundle penetrates white body.
      
      
9. Shell
   1. Saddle-shaped: Broad saddle with two lobe-like, deeply escavated flared wings, pronounced shoulders.
      image info image info

      Left, middle - Ventral and dorsal views of the shell of Cirroteuthis muelleri. Drawings from Voss and Pearcy (1990). Right - Dorsal view of the shell of Cirrothauma murrayi. Drawing from Aldred et al. (1983).

References

Aldred, R. G., M. Nixon and J. Z. Young. 1983. Cirrothauma murrayi Chun, a finned octopod. Phil. Trans. Roy. Soc. Lond. 301: 1-54.

Voss, G. L. and W. G. Pearcy. 1990. Deep-water octopods (Mollusca: Cephalopoda) of the Northeastern Pacific. Proc. Calif. Acad. Sci., 47: 47-94.