Echinoteuthis danae (Joubin, 1933)

Introduction

Joubin (1933) collected 18 young squid of this species but based his description on three specimens, 61 (arm tip to tail), 45 and 17 mm (tentacle tip to tail). All specimens, in spite of the rather large size, these are paralarvae that lack most subadult characteristics.

Brief diagnosis:

An Echinoteuthis with ...

• large tubercules in advanced paralarvae.
• a fin that is longer than wide.

Characteristics

1. Arms
   1. Arm suckers without teeth.
   

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   Figure. Oral-oblique view of arm IV sucker of E. danae, specimen 1. Drawing from Joubin (1933).

2. Tentacles
   1. Stalk about 2 mm in length and slender.
   2. Club enlarged in diameter, ca. 7 mm long.
   3. Club tip slender, ca. 3 mm long, with sucker buds.
   

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   Figure. Lateral view of the club of specimen 2 of E. danae, 45 mm total length, ca. 20 mm ML (without tail). 16°N, 62°W. Drawing from Joubin (1933).

3. Head
   
   1. Funnel pocket unknown.
      
      
4. Funnel locking-apparatus
1. Funnel locking-apparatus with a very large tragus and a distinct antitragus.


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Figure. Funnel/mantle locking-apparatus of E. danae. Left - Ventral view of funnel component. Right - Dorsal view of mantle component. Drawings from Joubin (1933).

5. Mantle and Skin
1. Mantle and other skin, except fins, covered with small, cartilagenous tubercules.
2. Tubercules absent from a 17 mm total length specimen.


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Figure. Left - Side view of the head of E. danae, ca 45 mm ML. Right - Shape of tubercules. A - External view. B - Side view. Drawings from Joubin (1933).

6. Fins
1. Fins longer than broad.
2. Long tail present in small paralarvae but nearly absent in large paralarvae.


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Figure. Fins and tail of E. danae, specimen 2 (ca. 20 mm ML, without tail). Drawing from Joubin (1933).

7. Photophores
1. Photophores absent.
   
   
8. Pigmentation
1. Few chromatophores present.
   
   
9. Measurements

   Total length	61 mm to tip of arm IV	45 mm to tip of tentacle
   Mantle length (without fins)	25 mm
   Mantle length (with fins)*	46 mm
   Head width	17 mm
   Head length	7 mm
   Fin length	25 mm	11 mm*
   Fin width	17 mm	7 mm
   Arm I, length	3 mm
   Arm II, length	5 mm
   Arm III, length	4 mm
   Arm IV, length	14 mm
   Tail	< 1 mm*	9 mm
   Tentacle length	--	45 mm

Comments

This description is taken from Joubin (1933). E. danae is known only from paralarvae and may represent the young stage of a known species, perhaps E. atlantica.

Distribution

Type locality: North Atlantic; 34°40'N, 33°16'W, SE of the Azores; 16°03'N, 62°29'W near the Antilles; 30°51'N, 21°00'W east of the Canary Islands.

Salcedo-Vargas (1997) described four specimens (15-30 mm ML) from off Somalia, western Indian Ocean.

References

Joubin, L. 1933. Notes préliminaires sur les Céphalopodes des croisières du Dana (1921-1922). 4e Partie. Annales de l'Institut Océanographique, new series, 13: 1-49.

Salcedo-Vargas, M. A. 1997. Cephalopods from the Netherlands Indian Ocean Programme (NIOP) - II. Mastigoteuthid lineage and related forms. Beaufortia, 47: 91-108.