Mastigoteuthis dentata Hoyle, 1904

Introduction

Hoyle (1904) based his description of M. dentata on two specimens from the Eastern Tropical Pacific, neither had tentacles. One specimen (male, 72 mm ML, captured off Cape Mala, Panama), subsequently, was designated as the lectotype as the other has been lost (Young, 1972). Young (1972) reported additional features from a damaged specimen taken off Cape Mala.

Diagnosis

A mastigoteuthid and member of the M. grimaldii group (integumental photophores, toothed arm suckers, small club suckers where known) ...

• with an enlarged eyelid photophore.
• with an eastern tropical Pacific habitat.

Characteristics

1. Arms
1. Arm suckers with teeth on distal half of inner ring (Hoyle, 1904); Distal half with long, pointed teeth blending into short, broadly truncate teeth proximally, 23 teeth total (Young, 1972, Cape Mala specimens, drawing on near right, bottom).

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Figure. Oral view of arm suckers of M. dentata. Left - Arm III, Cape Mala, lectotype. Drawing from Young (1972). Middle - Arm IV. Drawing from Hoyle (1904). Right - Oral view of proximal segment of the outer ring of an arm IV sucker. Drawing from Hoyle (1904).

 

2. Tentacles
   1. Length apparently half of tentacle length (Young, 1972, examination of lectotype).
   2. Suckers in 35-40 series (Young, 1972, examination of lectotype).
   3. Largest suckers ca one third of club length from distal end (Young, 1972, Cape Mala specimens).
   4. Basal club suckers smaller and less thickly spaced (Young, 1972, examination of lectotype).
   5. Suckers decrease in size near lateral margins of club (Young, 1972, examination of lectotype).
   6. Club sucker circular, rings with virtually smooth inner margins.
   7. Outer rings of club suckers with 12-14 small pegs projecting slightly into aperature.
   8. Club sucker diameter 0.13-0.16 mm (P.L. 92 mm)

   image info

   Figure. Oral view of club sucker of M. dentata, Cape Mala, lectotype. Left - Inner ring. Right - Outer ring. Drawings from Young (1972).

 

3. Funnel locking-apparatus
1. Funnel locking-apparatus with tragus and weak antitragus; area of antitragus well undercut (Young, 1972, examination of lectotype).

 

4. Mantle
1. Tubercules absent.

 

5. Fins
1. 43-67% of ML (Hoyle, 1904). 66-67% of ML (Young, 1972, Cape Mala specimens).

 

6. Photophores
1. Integumental photophores cover body (Young, 1972, based on lectotype).
2. Eyelid photophore present (Young, 1972, examination of lectotype).

 

7. Measurements

Source	Hoyle, 1904
Mantle length	72
Mantle width	17
Head width	17?
Fin length	48
Fin width	52
Arm I, length: Right / Left	37 / 38
Arm II, length	44 / 47
Arm III, length	45 / 42
Arm IV, length	87 / 78

*Measurements in mm.

Distribution

Type locality: Gulf of Panama, off Cape Mala, Panama at 7°21'N, 79°35'W. The original description included two specimens, one from off Cape Mala and the other from near the Galapagos Isl. Since the Cape Mala specimen has been designated as the lectotype, its place of capture becomes the type locality.

References

Hoyle, W.E. 1904. Reports on the Cephalopoda. Bulletin of the Museum of Comparative Zoology at Harvard College, in Cambridge, 43(1):1-72.

Young, R. E. 1972. The systematics and areal distribution of pelagic cephalopods from the seas off Southern California. Smithson. Contr. Zool., 97: 1-159.