Discoteuthis sp. A

Introduction

An unusual specimen of Discoteuthis was recently described (Salcedo-Vargas and Guerrero-Kommritz, 2000) that has a distinctive array of photophores. The squid was a mature male which raises the possibility that it could be the unknown mature male of Discoteuthis discus. Although the photophore arrangement is different than this species, some oegopsid squids show remarkable changes at sexual maturity. If this is not the case, then the species represents the third known species in the genus.

Diagnosis

A Discoteuthis ...

• with a diagonal groove in the funnel locking-apparatus.
• with a row of photophores on arms IV,  some on the head and one at ventral mantle apex.
  

Characteristics

1. Tentacles
   1. Dactylus with suckers in four series.
   2. Medial suckers of manus with smooth inner rings.
   

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   Figure. Oral view of the tentacular club of Discoteuthis sp. A. Drawing from Salcedo-Vargas and Guerrero-Kommritz (2000).

2. Funnel
   1. Funnel locking-apparatus with diagonally positioned groove (similar to that of D. discus).
   

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   Figure. Frontal view of the funnel locking-apparatus of Discoteuthis sp. A. Drawing from Salcedo-Vargas and Guerrero-Kommritz (2000).

3. Mantle
   1. Free anterior margin of mantle smooth (i.e., flaps lacking).
      
      
4. Photophores
1. A series of 7 (possibly more) photophores embedded in aboral surface of each arm I.
2. Three to 4 photophores embedded in skin of head around each eye (7 or 8 total).
3. Large, round photophore (10 mm diam.) on ventral side of posterior tip of mantle.


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Figure. Ventral views of portions of Discoteuthis sp. A showing photophores (blue dots). Left - Mantle and fins. Right - Head and ventral arms. Drawings modified from Salcedo-Vargas and Guerrero-Kommritz (2000).

Comments

This squid is most similar to D. discus. It differs in the size and arrangement of photophores, and club-sucker dentition. Additional features of the description can be found here.

Life History

Distribution

References

Salcedo-Vargas, M. A. and J. Guerrero-Kommritz. 2000. Three new cephalopods from the Atlantic Ocean. Mitt. Hamb. Zool. Mus. Inst., 97: 31-44. Three new cephalopods from the Atlantic Ocean. Mitt. Hamb. Zool. Mus. Inst., 97: 31-44.