Heteroteuthis sp. A

Introduction

The only known specimen of Heteroteuthis sp. A is a female that was taken from the stomach of the fish Alepisaurus ferox off New Caledonia.

Brief diagnosis:

A Heteroteuthis with ...

• deep, angled posterior pit in funnel-locking groove.
• fused nuchal cartilage but free dorsal mantle margin.
• thick iridophore layer on posteroventral surface of funnel.

Characteristics

1. Arms (female)
   1. Arms subequal in lenght with arms III slightly the longest.
      
      

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      Figure. Oral view of the brachial crown of Heteroteuthis sp. A, female. Photograph by R. Young.

   2. Tips (distal 10% of arm) without suckers on arms I, III and IV; arms II with suckers to tip.
      
   3. All arms I-III with keels, arms IV with lateral membrane; arms I and III with distal flags but uncertain if flags on arms II.
      

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      Figure. Oral view of left arms I-IV of Heteroteuthis sp. A showing bare arm tips on arms I, II, IV (arrows). Note the large distal, aboral keels on arms I and III. Photograph by R. Young.

2. Head
   
   1. Small ocular pore on secondary eyelid just anterior to lens.
      
   
   
   

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   Figure. Dorsolateral view of the head of Heteroteuthis sp. A showing the ocular pore (arrow). Photograph by R. Young.
3. Funnel
   1. Funnel component of the funnel/mantle locking-apparatus slightly boomerang-shaped with deep, angular pit at bend and narrow grooves on either limb. Mantle component with slender ridges extending to a high point at bend which is in posterior half of lock. Anterior edge does not reach mantle margin.
      
   2. Funnel connected to head by broad funnel adductor muscles that attach to funnel near distal sides of funnel lock.
      
   

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   Figure. Funnel/mantle locking-apparatus of Heteroteuthis sp. A. Left - Side view of mantle component. Right - Frontal view of funnel component. Photographs by R. Young.

4. Mantle
   1. Mantle margin free but nuchal cartilage fused to mantle.
      
   2. Ventral mantle shield confined to anterior half of mantle (see photograph under "Photophores").
      
   

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   Figure. Dorsolateral view of the nuchal fushion (arrow) in Heteroteuthis sp. A. Photograph by R. Young.

5. Pigmentation/iridophores
   1. Thick iridophore layer present on posteroventral surface of funnel.
      
   

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   Figure. Ventral view of the funnel of Heteroteuthis sp. A showing iridophore layer (arrow). Photograph by R. Young.

Comments

More details of the description of Heteroteuthis sp. A can be found here. 

Heteroteuthis sp. A is only known from an immature female. Nevertheless, it is very distinct. It  differs from other species of Heteroteuthis in (1)  having a fused rather than a free nuchal cartilage, (2) having short, bare regions on arms I, III and IV but having suckers to the tips of arms II (presumably in females only), (3) very differently shaped funnel/mantle locking-apparatus, (4) bare club tips, (5) different pigmentation, (6) eye with an ocular pore, (7) thick iridophore layer on the posteroventral surface of the funnel, and (8) large, distal, aboral flags on arms I and III.

Distribution

The single female was taken on April 22, 2004 off New Caledonia from the stomach of 104 cm Alepisaurus ferox caught at 22°27'S, 166°17'W.