Date of Award


Publication Type

Doctoral Thesis

Degree Name



Biological Sciences

First Advisor

Sale, Peter F.,


Agriculture, Fisheries and Aquaculture.




This dissertation represents a comprehensive investigation into the behaviours, social interactions, microhabitat use, and spatial dynamics of six ecologically and morphologically similar Caribbean labrid species. The following species were included: Halichoeres bivittatus, H. garnoti, H. maculipinna, H. poeyi, H. radiatus, and Thalassoma bifasciatum. The first study (Chapter II) examined the relationship between fish size and home range area and found a strong, positive relationship for all species. It was also observed that within their individual home ranges, labrids concentrate their activities in core use areas. The second study (Chapter III) investigated behavioural similarities among these species and their life stages. These labrids showed a high degree of overlap in their behaviours. There was a remarkable similarity in ontogenetic changes in these behaviours among the species. As these labrids grow, they spend more time swimming alone, and less time hovering and searching for food. The third study (Chapter IV) investigated the distribution of behaviours and species interactions within home ranges. Some behaviours were randomly distributed throughout home ranges whereas others were non-randomly distributed. On average, individual fish of all species showed higher frequencies than expected of agonistic interactions with damselfish in the peripheral region of their home ranges. This suggested a large influence of the position of damselfish on labrid spatial arrangements. The fourth study (Chapter V) examined microhabitat use. There was a high degree of variability in microhabitat use among individuals within a species. However, all species showed increasing preference for less topographically complex microhabitats as they grow. The fifth study (Chapter VI) was a manipulative field experiment that demonstrated a mechanistic influence of territorial pomacentrids on space use in one labrid species, H. bivittatus. These individuals relocated their home ranges after beaugregory damselfish, Slegastes leucostictus, were introduced into their core use areas. In the final study (Chapter VII), the effects of environmental factors on labrid assemblage structure were explored. It was found that zonation is a primary factor affecting labrid assemblage structure. On the back reef, several species were negatively associated with adult beaugregory damselfish. Statistical analyses revealed associations between some labrids and microhabitats that were consistent with observations of microhabitat selectivity within individual home ranges.Dept. of Biological Sciences. Paper copy at Leddy Library: Theses & Major Papers - Basement, West Bldg. / Call Number: Thesis2000 .J66. Source: Dissertation Abstracts International, Volume: 62-10, Section: B, page: 4289. Adviser: Peter F. Sale. Thesis (Ph.D.)--University of Windsor (Canada), 2000.