Grimpoteuthis boylei Collins 2003

Introduction

Grimpoteuthis boylei is a large abyssal species described from the N. E. Atlantic from ten individuals.

Characteristics

1. Arms and web
   
   

   Click on an image to view larger version & data in a new window

   

   Figure. Oral view of arms and web of G. boylei, paratype, female, 115 mm ML. Drawing from Collins (2003).

   1. Arms long, subequal in length.
   2. Web extends 2/3 of arm length; extends further on dorsal arms.
   3. Web formula: A>B>C>D>E.
   4. Single web nodule prominent on ventral side of each arm; located at sucker 31 (arm I), 28 (arm II), 25 (arm III) or 24 (arm IV).
      
      

      Click on an image to view larger version & data in a new window

      

      Figure. Oral view of arm I of G. boylei, holotype, male, 90 mm ML. Drawing from Collins (2003).

   5. Sucker count 55-58.
   6. Maximum sucker diameter between suckers 25 and 35.
   7. Cirri long (mean CLI 12.2).
   8. First cirri between suckers 4 and 7.
      

      Click on an image to view larger version & data in a new window

      
      

      Figure. Lateral view of suckers and cirri of G. boylei, holotype, male, 90 mm ML. Drawing from Collins (2003).

2. Shell
   1. U-shaped with distinct depression on outer surface of saddle.
   2. Inner surface of saddle convex.
   3. Lateral wing with blunt termination.
      
      

      Click on an image to view larger version & data in a new window

      

      Figure. Lateral (left), dorsal (middle) and ventral (right) views of the shell of G. boylei, male, 65 mm ML. Drawings from Collins (2003).

Comments

The above description is from Collins, 2003. More details of the description of G. boylei can be found here. The holotype is a 90 mm ML male.

Among other Atlantic species, Grimpoteuthis boylei differs in having a depression on the outer surface of the shell saddle. In addition it differs from:

• G. challengeri in the presence of posterior salivary glands, shape of the gills (broad rather than slender lamellae), egg size (18-20 mm vs 13 mm) and the number, form and arrangement of the suckers (Collins, 2003).
• G. discoveryi in the shape of the shell wing (wing ends in one vs two lobes), in the presence of a radula, in the presence of posterior salivary glands, in generally 8 vs 7 gill lamellae and the large size at maturity (265 vs 152 mm total length in females)(Collins, 2003).
• G. megaptera in geographic distribution (Eastern vs Western North Atlantic) and, perhaps, the larger sucker size (Collins, 2003).
• G. plena in geographic distribution (Eastern vs Western North Atlantic) and the longer cirri (ca. 2 vs 1.5x). What little is known about G. plena suggests that it is very close to G. boylei.(Collins, 2003).
• G. umbellata in the greater number of suckers (55-58 vs 65-68) and the greater depth range (>4000m vs <2500 m)(Collins, 2003).
• G. wuelkeri in longer cirri in females (2.2x vs 1.2x), fewer suckers (55-58 vs 60-70), generally 8 vs 6-7 gill lamellae, Shell without a ridge on the outer surface of the shell saddle, larger eggs (18-20 vs 14mm) and the greater depth range (>4000 vs <2100 m)(Collins, 2003).

Life History

Distribution

The type locality is the Porcupine Abyssal Plain at 48°47'N, 16°30'W; depth - 4845-4847 m. In addition to the type locality this species is known from the Porcupine Seabight and the Madeira Abyssal Plain but probably occurs from 20°N to 50°N in the NE Atlantic (Collins, 2002).

References

Collins, M. A. 2003. The genus Grimpoteuthis (Octopoda: Grimpoteuthidae) in the North-east Atlantic, with descriptions of three new species. Zool. Journ. Linnean Soc., 139: 93-127.