AGONISTIC CONTESTS IN MALE FORM I CAMBARUS BARTONII BARTONII (FABRICIUS, 1798) (DECAPODA, CAMBARIDAE) CRAYFISH AND A COMPARISON WITH CONTESTS OF THE SAME TYPE IN CAMBARUS ROBUSTUS GIRARD, 1852

Abstract

AbstractDuring contests between evenly size-matched Cambarus bartonii bartonii crayfish males of reproductive form (Form I), the eventual winners performed significantly more total initiation acts, Lunge and Claws Raised initiation behaviours than the eventual losers. There were no significant differences between the numbers of Ambivalent Contact initiation acts and tail flip escape behaviours, respectively, performed by the winners and the losers. During intraspecific, intra-form contests, C. b. bartonii Form I males used the same three main types of initiation acts as Form I males of the closely related species Cambarus robustus. The highly aggressive Lunge initiation act plays a much more important role in the establishment of the dominant-subordinate relationship in the C. robustus intraspecific, intra-form Form I contests than in the C. b. bartonii contests of the same type. The eventual C. b. bartonii losers were considerably less submissive in the intraspecific contests in comparison to the interspecific contests against C. robustus. The decline in both the number of fights and the time spent fighting, which accompanied the establishment of the dominant-subordinate relationship in the C. robustus intraspecific contests, did not take place during the C. b. bartonii intraspecific contests. Pendant les confrontations entre ecrevisses males de taille assortie de l'espece Cambarus bartonii bartonii, appartenant a la forme reproductive (Forme I), les gagnants eventuels accomplissent de facon significative un plus grand nombre total d'actes d'engagement ("Lunge" et "Claws Raised") que les perdants eventuels. Il n'y avait pas de differences significatives entre les nombres des actes d'engagement "Ambivalent Contact" et de degagement "en coup de queue", respectivement, accomplis par les gagnants et les perdants. Pendant les confrontations intraspecifiques, intraformes, les males de C. b. bartonii utilisaient les trois memes types principaux d'actes d'engagement que les males Forme I de l'espece tres proche Cambarus robustus. L'acte d'engagement hautement agressif "Lunge" joue un role beaucoup plus important dans l'etablissement de la relation dominant-domine dans les confrontations intraspecifiques, intraformes Forme I, chez C. robustus, que dans les confrontations de meme type chez C. b. bartonii. Les eventuels perdants de C. b. bartonii etaient considerablement moins soumis dans les combats intraspecifiques que dans les combats interspecifiques contre C. robustus. Le declin, a la fois dans le nombre des combats et dans le temps passe a combattre, qui accompagnait l'etablissement de la relation dominant-domine dans les rencontres intraspecifiques chez C. robustus, n'intervenait pas pendant les rencontres intraspecifiques chez C. b. bartonii.