The tubenose goby (Proterorhinus semilunaris) entered the Great Lakes in the 1990s via ballast water, but remains poorly studied within North America, making it difficult to predict its effects on native ecosystems. Dietary breadth and somatic growth rate have important ramifications for survival, competitiveness, and dispersal ability of a fish species, and thereby its ecological impact. We studied diet and growth of age-0 tubenose goby within the St. Louis River, a tributary to Lake Superior that contains the largest population within the Lake Superior basin. We sampled tubenose gobies from shallow, vegetated habitats during summer and fall. Stomach contents were identified and weighed to measure fullness and dietary breadth between seasons and several locations. We aged fish based on otolith daily increments to model somatic growth. Diet was dominated by isopods and amphipods, and dietary breadth was low and not significantly different between locations and seasons. Tubenose goby diet strongly overlapped with that of tadpole madtom (Noturus gyrinus), a native, demersal species. We tested several candidate growth models; the Gompertz growth function was the most parsimonious model among those examined. The model demonstrates that tubenose goby obtains a small maximum size and is short-lived. We conclude that tubenose goby presents a unique risk to the Great Lakes and other freshwater bodies because their life history is typical of invasive species, their diet overlaps with native fish, and because they occupy shallow, vegetated habitat which functions as both nursery and foraging habitat for many native fishes.
Bibliographical noteFunding Information:
We thank Graham Hanson, Jonathon Barge, Mark Pearson, Chelsea Hatzenbuhler, Adam Frankiewicz, Matt Pawlowski, Mike Kahl, Jill Scharold, Sara Okum, Erik Pilgrim, and Alexander Cole for help with data collection and sample analysis. Hannah Ramage, Anna Hall, Josh Dumke, and Nick Bogyo provided samples for this project. Donn Branstrator, Tedy Ozersky, Brian Matthias, and Quinn Smith contributed statistical and editorial advice. The views expressed in this paper are those of the authors and do not necessarily reflect the views or policies of the U.S. Environmental Protection Agency. This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.
- Gompertz growth function
- Great Lakes
- Invasive species
PubMed: MeSH publication types
- Journal Article