Environmental Biology of Fishes

, Volume 39, Issue 3, pp 219–229

Observations of the mating behavior and dentition of the round stingray,Urolophus halleri

  • Shawn E. Nordell
Full paper

DOI: 10.1007/BF00005124

Cite this article as:
Nordell, S.E. Environ Biol Fish (1994) 39: 219. doi:10.1007/BF00005124


The mating behavior and dentition ofUrolophus halleri, the round stingray was examined. Males frequently bite females during the mating period but most male biting does not result in copulation. In bites that do not lead to copulation, males bite the posterior (or occasionally the medial) portion of the females' disc but females often free themselves from these bites. In bites that precede copulation, males bite the anterior portion of the females' disc and females do not struggle to free themselves. Thus, females may exert some form of choice when they are bitten. Mature males have sexually dimorphic dentition that may aid in holding females. A principal component analysis (PCA) showed that in juvenile males, the relative size of the teeth decrease while the relative thickness of the disc increases as body size enlarges; adult males displayed no clear pattern. In adult females, there is a relative decrease in tooth size and increase in relative disc thickness as body size enlarges. The relative increase in females disc thickness in areas where they are bitten may function to minimize the amount of damage due to non-copulatory biting. There is no indication that biting functions to induce female receptivity but it may allow females and males to acquire information about potential mates. Thus, copulatory biting functions to maintain contact during copulation while the function of non-copulatory biting is less clear.

Key words

Sexual dimorphism Biting Elasmobranch Dasyatidae Multivariate analysis 

Copyright information

© Kluwer Academic Publishers 1994

Authors and Affiliations

  • Shawn E. Nordell
    • 1
  1. 1.Department of Ecology and Evolutionary BiologyUniversity of ArizonaTucsonU.S.A.
  2. 2.Department of BiologyUniversity of New MexicoAlbuquerqueU.S.A.

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