Polar Biology

, Volume 15, Issue 1, pp 9–14 | Cite as

The use of beaks as tools for biomass estimation in the deepwater squid Moroteuthis ingens (Cephalopoda: Onychoteuthidae) in New Zealand waters

  • George D. Jackson
Original Paper


Beak lengths (lower rostral length and upper rostral length) were taken for a sample of Moroteuthis ingens which were captured on the Chatham Rise, New Zealand. Beak lengths were plotted against both mantle length and wet weight to determine the relationship between these parameters for future use in biomass estimates in predator analysis. Although M. ingens is markedly sexually dimorphic, with females reaching 5 times the weight of males, there was no obvious sexual dimorphism in either lower or upper rostral length. This resulted in sex-specific relationships between both LRL and mantle length, LRL and weight; and URL and mantle length, and URL and weight. Males appeared to have a curvilinear relationship between beak length and mantle length and beak length and weight (even for log-transformed data). There was also considerable spread in the data in the plot between beak length and weight for females of similar weight. These characteristics of the data makes biomass estimates based on rostral length measurements for this species difficult. Other beak parameters may prove more useful for estimating biomass of M. ingens.


Biomass Sexual Dimorphism Length Measurement Biomass Estimate Similar Weight 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


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  1. Cherel Y, Verdon C, Ridoux V (1993) Seasonal importance of oceanic myctophids in king penguin diet at Crozet Islands. Polar Biol 13:355–357Google Scholar
  2. Clarke MR (1980) Cephalopoda in the diet of sperm whales of the southern hemisphere and their bearing on sperm whale biology. Discovery Reports 37:1–324Google Scholar
  3. Clarke MR (1983) Cephalopod biomass — estimation from predation. Mem Nat Mus Vict 44:95–107Google Scholar
  4. Clarke MR (1986) A handbook for the identification of cephalopod beaks. Clarendon Press, Oxford, p 273Google Scholar
  5. Green K, Burton HR (1993) Comparison of the stomach contents of southern elephant seals. Mirounga leonina, at Macquarie and Heard Islands. Mar Mam Sci 9:10–22Google Scholar
  6. Jackson GD (1993) Growth zones within the statolith microstructure of the deepwater squid Moroteuthis ingens (Cephalopoda: Onychoteuthidae): Evidence for a habitat shift? Can J Fish Aquat Sci 50:2366–2374Google Scholar
  7. Jackson GD, Mladenov PV (in press) Terminal spawning in the deepwater squid Moroteuthis ingens (Cephalopoda: Onychoteuthidae). J Zool LondGoogle Scholar
  8. Lipinski MR, Linkowski TB (1986) Some aspects of the biology of the squid Moroteuthis ingens (Onychoteuthidae) from New Zealand Waters. Reps Sea Fish Inst 21:97–105Google Scholar
  9. Nemoto T, Okiyama M, Iwasaki N, Kikuchi T (1988) Squid as predators on krill (Euphausia superba) and prey for sperm whales in the Southern Ocean. In: Sahrhage D (ed) Antarctic ocean and resources variability. Springer, Berlin Heidelberg New York, pp 292–296Google Scholar
  10. Pascoe PL, Mickiewicz MC, Castello HP (1990) Cephalopod remains from the stomach of a sperm whale stranded off Patagonia. Mar Biol 104:1–4Google Scholar
  11. Rodhouse PG (1989) Antarctic Cephalopods — A living marine resource? Ambio 18:56–59Google Scholar
  12. Rodhouse PG (1990) Cephalopod fauna of the Scotia Sea at South Georgia: potential for commercial exploitation and possible consequences. In: Kerry KR, Hempel, G (eds) Antarctic ecosystems. Ecological change and conservation. Springer, Berlin Heidelberg New York, pp 289–298Google Scholar
  13. Rodhouse PG (1991) Population structure of Martialia hyadesi (Cephalopoda: Ommastrephidae) at the Antarctic Polar Front and the Patagonian shelf, South Atlantic. Bull Mar Sci 49:404–418Google Scholar
  14. Rodhouse PG, Clarke MR, Murray AWA (1987) Cephalopod prey of the wandering albatross Diomedea exulans. Mar Biol 96:1–10Google Scholar
  15. Rodhouse PG, Arnbom TR, Fedak MA, Yeatman J, Murray AWA (1992) Cephalopod prey of the southern elephant seal, Mirounga leonina L. Can J Zool 70:1007–1015Google Scholar
  16. Rosecchi E, Tracey DM, Webber WR (1988) Diet of orange roughy, Hoplostethus atlanticus (Pisces: Trachichthyidae) on the Challenger Plateau, New Zealand. Mar Biol 99:293–306Google Scholar

Copyright information

© Springer-Verlag 1995

Authors and Affiliations

  • George D. Jackson
    • 1
  1. 1.Department of Marine ScienceUniversity of OtagoDunedinNew Zealand

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