Berryteuthis magister shevtsovi Katsugin, 2000

Introduction

B. m. shevtsovi was described by Katugin (2000) based on 7 adult specimens collected by bottom trawl from the continental slope of the Japan Sea at 600m depth. One male (162mm ML) and one female (172mm ML) were designated as holotype and paratype, respectively.

Diagnosis

A Berryteuthis with ...

• small size at maturity (females<20cm ML, males<17cm ML).
• large fins (FL=50% ML, FL=77% ML)
• weakly differentiated hookless tentacular club.
• small differences between central and marginal suckers on the manus.
• fixing apparatus consists of almost 40 elements.
• bicuspid lateral teeth of the radula.
• one of arms IV modified into hectocotylized arm with swollen base of dorsal marginal suckers at middle 1/3 of the arm.
• low fecundity (3755 eggs in B. m. shevtsovi vs. 25,000 eggs in B. magister).
• large eggs (largest egg diameter 5.9 mm).
  

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  Figure. Oral views of the tentacle and club, and arm IV of the holotype of Berryteuthis magister shevtsovi (162 mm ML). Drawings from Katugin (2000).

  

  Figure. Ventral and dorsal views of Berryteuthis magister shevtsovi identified by Okutani (2005) collected by K. Doi in the Sea of Japan. Photos from Okutani (2005).

Life History

No informations is available for early life history of this sub-species. Biological characteristics of B. magister, including possibly this sub-species, off northern Hokkaido and the Sea of Japan were reported by Kubodera (1992).

Distribution

The distribution of B. m. shevtsovi is confined in the Sea of Japan, 200-600m depth.

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Figure. Distribution of B. m. shevtsovi. Chart modified from Okutani (2005)

References

Katugin, O.N. 2000. A new subspecies of the schoolmaster gonate squid, Berryteuthis magister (Cephalopoda: gonatidae), form the Japan Sea. The Veliger 43(1): 82-97.

Kubodera, T. 1992. Biological characteristics ofthe gonatid squid, Berryteuthis magister (Cephalopoda: Oegopsida) off northern Hokkaid, Japan. Memoirs of the Nationa Science Museum, Tokyo 25: 111-123.

Okutani, T. 2005. Chuttlefishes and squids of the world. Publication for the 40th Anniversary of the Foundation of National Cooperative Association of Squid Prosessors, Tokyo.