Mastigoteuthis famelica (Berry, 1909)

Introduction

M. famelica is one of two common Mastigoteuthis species in the region of the Hawaiian Archipelago.

Brief diagnosis:

A member of the M. glaukopis Group with ...

• a Pacific Ocean Distribution.
  
• barely detectable protective membranes on tentacular clubs.

Characteristics

1. Tentacles
   1. Club with barely detectable protective membranes.
   2. Club suckers uniform in size over club until club diameter diminishes near tip where suckers become smaller.
      

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      Figure. Four views of club of M. familica, preserved, neotype. Left - Oral view in midregion of club. Left middle - Side view in midregion of club at lower magnification. Right middle - Aboral view in midregion of club. The distnctive mantle pigmentation is seen in the background.Right - Oral view of club base. The separate sucker patches on the latter may be an artifact of damage. The tentacle is a bit shriveled from long preservation. Photographs by R. Young.

   3. Club suckers slightly elongate, 0.36 mm in length, with 2-3 large, blunt knobs on each side of outer ring that project into aperature. Inner ring with 2 or 3 tiny rounded teeth on distal margin.
   

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   Figure. Oral view of preserved club suckers of M. famelica, neotype.

   Scanning electron micrographs of the suckers can be found here.

2. Head
   1. Beaks. Description of the beaks can be found here.
      
3. Fins
   1. Fins slightly longer than broad.
   2. Anterior and posterior fin lobes absent.


4. Photophores
   1. Eyelid photophore present; other photophores absent.
   

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   Figure. Lateral view of the head of M. famelica showing eye size and size of eyelid photophore (arrow), immature female, 140 mm ML, preserved, Hawaiian waters. The rather large eyelid photophore (ca 2.3% of ML in longest measurement) may be hidden by pigmentation. Photograph by R. Young.

Comments

More details of the description can found here.

M. famelica is very similar to M. atlantica from the central North Pacific in having large eyelid photophores, absence of all other photophores and fins that are slightly longer than wide. These two species clearly differ, however, in the size of the protective membrane on the tentacular clubs (well developed in M. atlantica and nearly absent in M. famelica). The small (37 mm ML, holotype) M. glaukopis from the Indian Ocean as described by Chun (1910) is very similar except for differences in the size and dentition of the club suckers. Since these latter features change with size, we can find no differences that separate M. glaukopis Chun, 1908 and it is probably synonymus with M. atlantica Joubin, 1933 or M. famelica Berry, 1909, but has priority over both. Until larger specimens of M. glaukopis are available from the Indian Ocean, we maintain all three species. We suspect, however, on the basis of the distinct protective membrane on the tentacular club in the illustrations of Chun (1910) that M. glaukopis and M. atlantica may be synonymus.

Nomenclature

The holotype is no longer extant (Sweeney, et al., 1988) and we designate the specimen described here (immature female, 241 mm ML), Museum No. xxx, as the neotype. Nesis (1980) incorrectly synonymized this species (it had been incompletely described at the time as Chiroteuthis famelica) Berry, 1909 with Chiroteuthis acanthoderma (= Asperoteuthis acanthoderma).

Life History

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Figure. Ventral and dorsal views of two Paralarval stages of M. famelica. Thumbnail (far left): Ventral view showing relative sizes of the two paralarvae. Left - 4.8 mm ML paralarva, Hawaiian waters.  Right: 8.5 mm ML paralarva, Hawaiian waters. Drawings from Young (1991).The scale bar is l mm.

Paralarvae

At 5 mm ML  M. famelica paralarvae are separated from similar-sized paralarvae of M. microlucens, the only other common mastigoteuthid in Hawaiian waters, by the more slender shape, smaller eyes, more anterior digestive gland and tentacular suckers and chromatophores extending much of the tentacle length.

At 7-9 mm ML arms III are only small papillae; the mantle is very slender; fins are large (length 1/3 of ML) and without anterior or posterior fin lobes; eyes each have a silvery rostrum projecting ventrally or anteriorly. Funnel organ with tragus and antitragus recognizable at 25 mm ML. At 7-9 mm ML the absence of fin lobes, the slender shape, elongate fins, tentacular stalk suckers and chromatophores also distinguishes M. famelica from M. microlucens. At larger sizes,  and, by at least  17 mm ML up to at least 40 mm ML, skin tubercules easily distinguish M. famelica. The differences between the two species diminish at sizes below 5 mm ML. The position of the digestive gland appears capable of distinguishing M. microlucens to at least 3.5 mm ML although the smallest M. familica paralarva examined was 4.8 mm ML.

Tubercles in paralarvae

Small multicuspid tubercles on mantle, funnel, head and aboral surface of arms seen in young of 17 - 42 mm ML. Most of the head tubercules are not visible in the photograph at the right but some on the funnel and its enlargement are visible.

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Figure. Left - Lateral view of preserved head and funnel of a paralarva of M. famelica, 35 mm ML, Hawaiian waters. Right - enlargement of a portion of the funnel, 35 mm ML, Hawaiian waters. Paralarva stained with methylene blue. Photographs by R. Young.

Distribution

Type locality: Vicinity of Kauai Island, Hawaiian Islands. Known only from the central north Pacific Ocean to about 3°S.

Vertical distribution

According to Young (1978), most specimens captured in his study were taken at depths between 675 and 800 m, both day and night. The two presummed contaminants were taken at 240 m during the day; the previous tow had fished at 700 m and captured three specimens.

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Figure. Vertical distribution chart of M. famelica. Captures were made with both open and opening/closing trawls. Bar - fishing depth-range of opening/closing trawl. Circle - Modal fishing depth for either trawl. Blue-filled circle - Night capture. Yellow-filled circle - Day capture. Unfilled circle - probable contaminant from previous tow. Note the breaks in the x-axis. Chart modified from Young (1978).

References

Nesis, K. N. 1980. Taxonomic position of Chiroteuthis famelica Berry. Bull. Moscow Obslich. Ispyt. Prirody, Section Biology, 85: 59-66. [In Russian]

Sweeney, M.J., C.F.E. Roper, and F.G. Hochberg. 1988. Catalog of the type specimens of Recent Cephalopoda described by S. Stillman Berry. Malacologia, 29(1):7-19.

Young, R. E. 1978. Vertical distribution and photosensitive vesicles of pelagic cephalopods from Hawaiian waters. Fish. Bull., 76: 583-615.

Young, R. E. (1991). Chiroteuthid and related paralarvae from Hawaiian waters. Bull. Mar. Sci., 49: 162-185.