TAXONOMIC ANALYSIS OF THE METRIACLIMA ZEBRA SPECIES COMPLEX IN LAKE MALAŴI WITH FIVE NEW SPECIES DESCRIPTIONS
Open Access
- Author:
- Black, Kristin Elizabeth
- Graduate Program:
- Wildlife and Fisheries Science
- Degree:
- Doctor of Philosophy
- Document Type:
- Dissertation
- Date of Defense:
- November 20, 2009
- Committee Members:
- Jay Richard Stauffer Jr., Dissertation Advisor/Co-Advisor
Jay Richard Stauffer Jr., Committee Chair/Co-Chair
C Paola Ferreri, Committee Member
Walter Matthew Tzilkowski, Committee Member
Ke Chung Kim, Committee Member
Ad Konings, Committee Member - Keywords:
- Lake Malawi
cichlid
mbuna
Metriaclima
M. pambazuko
M. lundoensis
M. midomo
M. tarakiki
M. nigrodorsalis - Abstract:
- Lake Malaŵi is an African rift lake sharing borders with Malaŵi, Tanzania, and Mozambique and is known for its speciose haplochromine cichlids – most notably, the endemic rock-dwelling cichlids known as mbuna. One of the larger genera of mbuna is Metriaclima, a group consisting of approximately 75 species which is diagnosed by its feeding behavior and several morphological characteristics including the presence of bicuspid teeth in the outer row of both the upper and lower jaws. The members of genus are found in clear waters at sediment-free rocky coasts and do not have a continuous distribution around the lake. Metriaclima zebra, the type species for genus Metriaclima, was described based on a single specimen. While the collection location of this holotype is not known, based on the travel records of its collector, it is likely the specimen originates from Likoma Island. This study included the morphological analysis of 1006 specimens of Metriaclima belonging to seventy collections from around Lake Malaŵi. Morphometric differences were analyzed using sheared principal component analysis (SPCA) of the morphometric data and principal component analysis (PCA) of the meristic data. The relationships among several color forms of Metriaclima were investigated and the holotype was compared to specimens from in and around Likoma Island to test the hypothesis that the location of origin for the type material is Likoma Island. The holotype was found to be morphologically similar to Likoma Island populations. Additionally, a distinctive yellow breasted M. zebra from Lumessi, Mozambique and Metriaclima sp. ‘blue blaze’ were regarded as conspecific with M. zebra based on the morphological analysis. This investigation resulted in the description of the following five new species belonging to the M. zebra species complex: M. pambazuko, M. lundoensis, M. midomo, M. tarakiki, and M. nigrodorsalis. These species were distinguished and described based on color patterns, and morphometric, meristic, and ecological differences. These new species were compared and distinguished from sympatric Metriaclima species and nearby populations of Metriaclima having similar color and pigmentation pattern and ecological niches. Lastly, a dichotomous key to the species of Metriaclima is presented.