Magnapinna pacifica Vecchione and Young, 1998

Introduction

Magnapinna pacifica, the type species of the family, was described from three individuals: Two juveniles about 50 mm ML and a paralarva of 19 mm ML. No additional specimens have been reported since the original description.

Diagnosis

A Magnapinna with ...

• proximal-tentacles wider than adjacent arms.
• numerous suckers on proximal-tentacles.

Characteristics

1. Arms.
   1. Proximal-arm suckers biserial distally, in 3 to 4 series at base.
   2. Distal-arms vermiform.
   3. Inner sucker rings probably smooth.
      image infoimage info

      Figure. Arms of M. pacifica, holotype, 51 mm ML. Left -Ventral and dorsal views of head and brachial crown. Right - Oral views of arms. A - Arm II. B - Arm III. Drawings from Vecchione and Young (1998).

2. Tentacles.
   1. Proximal-tentacles short, thicker than adjacent arms.
      image info

      Figure. Ventrolateral view of the brachial crown of M. pacifica, holotype, showing the large size of the proximal-tentacle relative to arm IV. Photograph by R. Young.

   2. Proximal-tentacle suckers small, in approximately eight series except at base.
   3. Sucker dentition unknown.
   4. Distal-tentacles vermiform.
      
      image info

      Figure. Filaments of M. pacifica, holotype, 51 mm ML . Left - Lateral view of tentacle-club. Middle - Oral view of tentacle-club. Drawing from Vecchione and Young (1998). Right - Dorsal view of head and brachial crown. Photographs by R. Young.

      image info

      Figure. Dorsolateral view of the head and brachial crown of M. pacifica, Berry specimen. This specimen had dried out and then been reconstituted. Note the large, broad tentacles and the elongate filaments of the arms which bear suckers in this, presumably, older individual.

3. Head
   1. Large eyes occupy most of head.
      
      
4. Funnel
   1. Funnel locking-apparatus with oval depression.
      image info

      Figure. Funnel locking-apparatus of M. pacifica, holotype. Arrow points to funnel lock, insert shows drawing of the same lock. Drawing from Vecchione and Young (1998). Photograph by R. Young.

5. Fins
   1. Fins very large: Length equal to or greater than squid length from posterior tip of muscular mantle to tip of tentacles.
   2. Fins terminal.
   3. Width approximates length.
      image info

      Figure. Ventral view of M. pacifica, paratype, 49 mm ML (USNM 885787). Photograph from Vecchione and Young (1998) which was found in the archives of S. S. Berry.

6. Photophores
   1. Photophores absent.
      
      
7. Measurements, mm

   	Holotype	Berry specimen
   Mantle length	51	49
   Muscular mantle length	16	17
   Gladius length*	53	52
   Fin length	39	40
   Fin width	34	41
   Head length	5	4
   Head width	7	5
   Eye diameter	4	3
   Arm I, left/right, to terminal sucker	2.3 / 2.4	-
   Arm II, left/right, to terminal sucker	3.9 / 3.5	-
   Arm III, left/right, to terminal sucker	2.9 / 2.7	-
   Arm IV, left/right, to terminal sucker	4.8 / 4.8	-
   Tentacle, left/right, to terminal sucker	7.1 / 7.4	-
   Arm I, left/right, terminal filament length	2+ / 1.3+	-
   Arm II, left/right, terminal filament length	2+ / 2.6	-
   Arm III, left/right, terminal filament length	2.6+ / 2.9	-
   Arm IV, left/right, terminal filament length	2.0 / 1.3+	-
   Tentacle, left/right, terminal filament length	2.2 / -	-

Life History

1. Arms
   1. Arms short, with suckers in 3-4 series at bases of arms III and IV; otherwise in two series.
   2. Arm tips bare and attenuate.
2. Tentacles
   1. Tentacles short, broad.
   2. Suckers in 7-8 series distally, grades into buds.
3. Fins
   1. Muscular mantle overlaps anterior of fins by 15% of fin length.
   2. Fins extend onto a tail posteriorly.
   image info

   Figure. Paralarvae of M. pacifica. Left - Ventral and dorsal views, 19.1 mm ML, Hawaiian waters. Middle - Dorsal view of head of same paralarva. Right - Tentacle of same paralarva. Drawings from Vecchione and Young (1998), modified.

Distribution

The holotype was taken off the California coast at a depth between 0 and 200m in a Bongo plankton net. The other juvenile was found in the stomach of the lancet fish Alepisaurus ferox and the paralarva was taken off Hawaii at a depth between 0 and 300 m in a 4 m2 plankton net.
The capture localities are:

• Holotype, 51 mm ML: 33° 49'N, 121° 51'W.
• Juvenile, 49 mm ML; 30° 22'N, 129° 45'W.
• Paralarva, 19.1 mm ML; 21° 20'N, 158° 20'W

image info

Figure. Distribution chart of M. pacifica. White dots indicate capture localities. Chart modified from Vecchione and Young (1998).

References

Vecchione, M. and R. E. Young. 1998. The Magnapinnidae, a newly discovered family of oceanic squids (Cephalopoda; Oegopsida). South African Journal of Marine Science, 20: 429-437.