Histioteuthis macrohista: Description continued

1. Photophores
   1. Compound photophores of uniform large size on anterior half of ventral mantle (a few minute photophores may be interspersed).
   

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   Figure. Ventral view of mantle of H. macrohista, holotype. Drawing extracted from Fig. 36a of Voss (1969).

   2. Compound photophores number usually 16 (rarely 15) on right eyelid.
   

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   Figure. Lateral view of right eyelid of H. macrohista, holotype. Drawing modified from Voss, 1969 (Fig. 36d).

   3. Arms IV with 3 longitudinal series on arm base.
   

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   Figure. Ventral view of arm IV of H. macrohista, holotype.  Drawing extracted from Fig. 36a of Voss (1969).

   4. Tips of arm I-III each with single, large, elongate, dark, simple, aboral photophore. Upper right drawing shows a side view and the lower drawing, an oral view.
   

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   Figure. Arm tips of H. macrohista. Left - Side view, paratype, 40 mm ML, male, Cook Strail, New Zealand. Drawing from Voss, 1969 (Fig. 37d). Right - Aboral view, holotype. Drawing from Voss, et al. (1998).

   5. Each posteroventral margin of head with two conspicuous, large, round dark photophores widely spaced.
   

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   Figure. Ventral view of enlarged head photophores of H. macrohista, 19 mm, juvenile, 45° 34'S, 147° 18'E. drawing from Voss, et al., 1998.

2. Tentacles
   1. Suckers on manus in 6 irregular series; median suckers moderately enlarged (1.5-2 times ventral-marginal suckers). Rings of enlarged suckers with numerous sharp teeth around entire margin.
      

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      Figure. Oral view of club of H. macrohista, holotype. Drawing from Voss, 1969 (Fig. 36b).

3. Arms
   1. Length 80-130% of ML.
      
      
4. Arm suckers
   1. Inner rings with 4-10 low, rounded or square teeth on distal and lateral margins.
      

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      Figure. Oral view of arm sucker of H. macrohista, holotype, middle of right arm III. Drawing from Voss, 1969 (Fig. 36c).

5. Web and buccal crown
   1. Inner web large; length more than 50% of longest arm length; outer web slightly developed.
   2. Buccal crown with 7 supports.
      

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      Figure. Oral view of the buccal crown of H. macrohista, paratype, 14 mm ML, male, 30° 15'S, 13° 15'E. Drawing from Voss, 1969 (Fig. 37f).

6. Funnel organ
   1. Heavy, swollen ridge on each lateral arm of dorsal pad.
      

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      Figure. Ventral view of the funnel organ of H. macrohista, paratype, female, 55 mm ML, west of Slangkop, South Africa. Drawing from Voss, 1969 (Fig. 37e).

7. Fins
   1. Length 52-56% of ML; width 80-89% of ML.
      
      
8. Spermatophores
   1. Length 7-8% of ML; sperm mass 7-8% of spermatophore length (SpL); cement body 64-74% of SpL; ejaculatory apparatus 26-27% of SpL. Ejacualtory apparatus with single loop. Connective complex present.
      
      
9. Hectocotylus
   1. Both arms I in mature males modified in distal third. Suckers abruptly reduced in size, and on elongated palisaded pedestals.

Comments

The above description is from Voss (1969) and Voss, et al. (1998).

References

Voss, N.A. 1969. A Monograph of the Cephalopoda of the North Atlantic. The Family Histioteuthidae. Bulletin of Marine Science, 19(4):713-867.

Voss, N.A., K. N. Nesis, P. G. Rodhouse. 1998. The cephalopod family Histioteuthidae (Oegopsida): Systematics, biology, and biogeography. In: Systematics and Biogeography of Cephalopods. (Voss, N.A., Vecchione, M., Toll, R.B. & Sweeney, M.J., eds.). Smiths. Contr. Zool., 586(2): 293-372.