Cooperative Behaviour in Fishes

Behavioral Ecology, 1998

Several hypotheses aim to explain the evolution of helping behavior, but conclusive experimental support for evaluating the relative importance of individual hypotheses is still larking We report on two field experiments* conducted to test the "territory inheritance" and "pay-to-stay" hypotheses in the cooperatively breeding cichlid fish Neolamprologus pulcher. The territory inheritance hypothesis was tested by removing one parent, which created breeding vacancies. In 39% of cases, same-sex helpers took over the breeding spot; in 44% of cases helpers continued helping new breeders, and 17% were evicted by new breeders. Helpers that were closely sjze matched to the removed breeder had a better chance of gaining the breeding spot Male helpers tended to continue helping after a takeover more often than females. The pay-to-stay hypothesis was tested by temporarily removing helpers. Whereas breeders did not respond aggressively to removals, other group members attacked the removed helpers on their return, and 29% were eventually evicted. The returning helpers assisted more by increasing their rate of territory maintenance and defense and visiting the brood chamber more frequently. Size and tex of removed helpers did not explain the observed aggressive reactions of other group members. Thus, our results support both hypotheses: N. pulcher needs to pay with help to be allowed to remain protected in the family group, and there they may inherit the natal territory. N. pulcher helpers gain direct benefits from helping behavior. Key words: riehlids, cooperative breeding, helping behavior,

The author has granted a non exclusive license allowing Library and Archives Canada to reproduce, publish, archive, preserve, conserve, communicate to the public by telecommunication or on the Internet, loan, distrbute and sell theses worldwide, for commercial or non commercial purposes, in microform, paper, electronic and/or any other formats. AVIS: L'auteur a accorde une licence non exclusive permettant a la Bibliotheque et Archives Canada de reproduire, publier, archiver, sauvegarder, conserver, transmettre au public par telecommunication ou par I'lnternet, preter, distribuer et vendre des theses partout dans le monde, a des fins commerciales ou autres, sur support microforme, papier, electronique et/ou autres formats.

2018

2003

Abstract Animals acquire skills and knowledge from other animals, and fish are no exception. There is now strong experimental evidence that many species of fish exhibit social learning and traditional behaviours. Here, we review the literature pertaining to social learning in fish, focusing on (i) antipredator behaviour,(ii) migration and orientation,(iii) foraging,(iv) mate choice and (v) eavesdropping.

Biological Reviews, 2011

The conundrum of why subordinate individuals assist dominants at the expense of their own direct reproduction has received much theoretical and empirical attention over the last 50 years. During this time, birds and mammals have taken centre stage as model vertebrate systems for exploring why helpers help. However, fish have great potential for enhancing our understanding of the generality and adaptiveness of helping behaviour because of the ease with which they can be experimentally manipulated under controlled laboratory and field conditions. In particular, the freshwater African cichlid, Neolamprologus pulcher, has emerged as a promising model species for investigating the evolution of cooperative breeding, with 64 papers published on this species over the past 27 years. Here we clarify current knowledge pertaining to the costs and benefits of helping in N. pulcher by critically assessing the existing empirical evidence. We then provide a comprehensive examination of the evidence pertaining to four key hypotheses for why helpers might help:

Social behavior is a common phenomenon among vertebrates, notably in fish, birds and mammals. It has been evolved within the species purposefully to support effective foraging, predation avoidance and fitness. Although all animals have predilection to live in a group, it is very intense in a few species. In many fish species it is an obligatory behavior, whereas in many other fish species it is opportunistic during group foraging and predator avoidance. Fish express their social behavior by enhancing the locomotor activity. The synchronization in locomotor activity reflects their social behavior based on interaction among members of the same species through sensory cues, like vision and olfaction (pheromones); and also is based on phenotypic characters, such as body size, body color and gender. It has also been reported that day and night cycle affects their social behavior. Study of inter-individual interaction under laboratory conditions often helps to understand intricacies of social behavior. The factors, such as group and group size may influence circadian periodicity in fish under different environmental conditions. In summary, such studies come under the fold of interesting researches in the realm of fish biology.

Proceedings of the Royal Society B: Biological Sciences, 2005

Many studies have attempted to explain the evolution of cooperation, yet little attention has been paid to what factors control the amount or kind of cooperation performed. Kin selection theory suggests that more cooperation, or help, should be given by relatives. However, recent theory suggests that under specific ecological and demographic conditions, unrelated individuals must 'pay to stay' in the group and therefore may help more. We tested these contrasting predictions using the cooperatively breeding fish, Neolamprologus pulcher, and found that the degree of work effort by helpers depended on which helping behaviours were considered and on their level of relatedness to the breeding male or female. In the field, helpers unrelated to the breeding male performed more territory defence, while helpers unrelated to the breeding female contributed less to territory defence. In the laboratory, unrelated group members helped more. Our work demonstrates that a number of factors in addition to kinship shape cooperative investment patterns.

edoc Publication server (Humboldt University of Berlin), 2020

First, I would like to thank Pawel Romanczuk, who created an unique working environment, whose advice has always helped me and who has supported me and inspired me in every possible way. Also for bringing the scientific world to us so vividly through a variety of conferences and collaborations. I owe many unique encounters, both human and scientific, to the CoCCoN network he initiated. Especially in these times of isolation it is a pleasure to think back. I would like to thank the people who shaped my daily work at the lab. It was a great pleasure for me to work with Winnie Poel, explore the research field of collective behavior and pursued the path to dissertation together. I owe Yinong Zhao many enthusiastic conversations about related scientific fields. Haider Klenz has humorously lit up the office and was a highly valued sitting neighbor. I was fortunate to explore the role of a supervisor with the talented interns Conor McBride, Alexandra (Olenka) Jain and Noam Miller. I would like to thank

Animal Behaviour, 2008

In cooperatively breeding species, members of social groups will risk serious injury or even their lives by actively codefending the communal territory and young in the territory. However, individuals within the group vary in the intensity and frequency of defence. To date little is known about how sex, body size and social status interact with the degree of threat to influence defence activities. To this end, we experimentally manipulated the need for defence in wild groups of the cooperatively breeding cichlid, Neolamprologus pulcher by exposing social groups to four intruder types representing different forms of threat. Intruders were introduced singly (experiment 1) to assess the costs and benefits associated with defence and in tandem (experiment 2) to assess how individuals prioritize perceived threats. Dominant breeders defended more than subordinate helpers, females were more aggressive than males, and female breeders defended more than any other individual in the group. Individual body size, or the difference in body size between intruders and defenders, had no influence on the frequency of defence. Dominant male breeders defended most vigorously against threats to their dominance position, while dominant female breeders showed the highest defence rates to both threats to their position and the security of young to a similar degree relative to all others. Predators evoked the strongest defence responses by subordinate helpers, and conspecific intruders evoked the weakest responses relative to all other intruder types. The results suggest that both costs and benefits have shaped aggressive defence patterns in this cooperatively breeding teleost fish.