Previous research
Here is an article by Kendall Clements about this work ( published in the Marsden Newsletter, March 2008) Read article
A major focus of my work has been the evolutionary radiation of New Zealand triplefin fishes (Family Tripterygiidae).
Notoclinops segmentatus, the blue eyed triplefin is a New Zealand endemic (photo by Kendall Clements)
Triplefin fishes are very diverse and abundant in New Zealand waters, and are unusual in that most species are broadly distributed throughout the region. My research involved fieldwork from the Three Kings Islands in the north to Stewart Island and Fiordland in the south, and investigated two key aspects of the New Zealand triplefin fauna: 1) habitat use, and 2) spawning and mate choice.
Maren Wellenreuther sampling triplefins in Fiordland, New Zealand
My work showed that habitat use was highly divergent between species, suggesting that diversification in habitat may have been important in the evolution of these fishes (Wellenreuther et al. 2007). This highly divergent habitat use is consistent around New Zealand (Wellenreuther et al, 2008), and habitat comparisons of newly settled recruits with conspecific adults suggest that habitat is activelty selected at settlement (Wellenreuther and Clements, in press). The second part of my research investigated which characters may have contributed to ensuring reproductive isolation among species. Little evidence was found for divergence in either breeding season or male colour pattern (Wellenreuther and Clements, 2007). However, habitat use was found to have a strong influence on breeding habitat, as triplefins court and mate in the same territory as that occupied year round (Wellenreuther and Clements, 2007). Furthermore, pairs of closely-related species were highly divergent in body size. Work on the two Ruanoho species showed that size affects their ability to compete for resources and is important in mate selection, suggesting that divergence in body size may have been important in their ecological diversification and in preventing hybridization (Wellenreuther et al., in press).
Overall, my results suggest that ecologically-based natural selection played an important role in the evolution of these fishes, and support the hypothesis that adaptation to different habitats has been a major factor in their speciation.
The rockpools species Bellapiscis medius in spawning colouration (photo by Kendall Clements)
Project collaborators: Kendall Clements and Craig Syms