New Neotropical cichlid species
During my Ph.D. I was lucky enough to lead the description and naming of two new species of South American cichlids.
Guianacara dacrya was described from specimens collected from both the Essequibo and Rio Branco drainages in Guyana. Interestingly, there is no permanent connection between the rivers inhabited by this species, but they are seasonally connected across the Rupununi savanna floodplains. This species likely disperses across these seasonal passageways, and this was supported by the lack of morphological divergence of populations from each drainage. This species was named for the tear-drop shaped mark under the eye.
I first became interested in Neotropical cichlids through my childhood hobby in aquarium fishes, with severum cichlids being some of my most beloved pets. I was thrilled just a year or so after the description of G. dacrya to see this species pop up in my local aquarium store in Toronto for the first time.
During my graduate studies, I had the opportunity to travel to Ecuador as part of a field expedition lead by Dr.Nathan Lujan. While sorting cichlid lots with Dr. Frances Hauser at the Museo de Historia Natural “Gustavo Orces V.” in Quito I stumbled across two jars of small fish collected in 1989 (nearly as old as I am!). While Dr. Hauser and I immediately recognized them as Bujurquina, a genus of cichlasomatines, the small speckles on the flanks immediately stood out as very strange and almost certainly meant it was a new species. I was determined to give these long languishing individuals a name.
However, most Bujuquina were described in a hard to find text from 1986, and no new species had been described since 1987, although several undescribed species may exist. As part of the description of this new species, I provided an updated key and guide to distinguishing markings, in the hopes of facilitating more research to explore this genus. They are named from the Latin term for leopard, in reference to their spotty sides.
Divergence in sympatric morphs of Arctic char from Ellesmere Island
For my honours thesis at Dalhousie University, I investigate morphological and genetic divergence of Arctic char from Lake Hazen, Ellesmere Island. Ellesmere island is the most northern island in the Canadian high arctic, and this post-glacial lake system has likely only existed for a few thousand years. These landlocked char are recent colonizers to this freshwater system, but are already represented by two distinct ‘types’, a large, silvery form that preys on other char, and a smaller, darker morph consuming benthic invertebrates. I found that the silver and dark forms varied significantly in body shape, head shape, fin shape and body shape allometry (changes in body shape with size). However, these two forms show no genetic divergence based on microsatellite loci, suggesting that phenotypic plasticity may play a role in the rapid divergence of these morphotypes.
Arbour, J.H., Barriga Salazar, R.E., López-Fernández, H. 2014. A new species of Bujurquina (Teleostei: Cichlidae) from the Río Danta, Ecuador, with a key to all species in genus. Copeia 2014(1):79-86. (link)
Arbour, J.H., Hardie, D. C.& Hutchings, J. A. 2011 Morphometric and genetic analyses of two sympatric morphs of Arctic char (Salvelinus alpinus) in the Canadian High Arctic. Canadian Journal of Zoology 89:19–30. (link)
Arbour, J.H. & López-Fernández, H. 2011. Guianacara dacrya, a new species from the rio Branco and Essequibo River drainages of the Guiana Shield (Perciformes: Cichlidae). Neotropical Ichthyology 9: 87–96. (link)