Category

Oral - Basic

Description

Mosquito fish (Gambusia holbrooki) are commonly found in local freshwater habitats and are highly regarded as an effective biocontrol agent for unwanted mosquito larvae. While an effective biocontrol, G. holbrooki and many kinds of freshwater fish are afflicted by various parasites (e.g. Blackspot). Blackspot is a disease caused by Schistosome-like parasites (flatworms) such as Uvulifer ambloplitis. U. ambloplitis cercariae attach to the muscle tissue of the fish, transform into black spot metacercaria, and secrete a hyaline cyst around themselves. The host fish deposits black pigment around the cyst and the parasite is visible as a black spot. While it is understood that this parasite changes the behavior (reproductive and shoaling) of Gambusia, it is not clear how the Cercariae/Metacercaria life stage may sub-lethally affect other life history patterns. This project investigated the circulation rates of G. holbrooki with and without blackspot by observing red blood cells (RBC/min) within the central capillaries in the tail region of 40 total fish (30 without blackspot & 10 with blackspot) at 100X magnification. Results indicated a significant difference in RBC counts of fish afflicted with blackspot in comparison to G. holbrooki free of blackspot. This information can be used to better understand the physiological effects of blackspot on Mosquitofish and how its infestation may impact the fish’s ability to be an effective biocontrol.

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Undergraduate - 1st Place Award Winner

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Apr 15th, 1:00 PM

ASSURE 2023: Gambusia vs. Blackspot Disease Study

Oral - Basic

Mosquito fish (Gambusia holbrooki) are commonly found in local freshwater habitats and are highly regarded as an effective biocontrol agent for unwanted mosquito larvae. While an effective biocontrol, G. holbrooki and many kinds of freshwater fish are afflicted by various parasites (e.g. Blackspot). Blackspot is a disease caused by Schistosome-like parasites (flatworms) such as Uvulifer ambloplitis. U. ambloplitis cercariae attach to the muscle tissue of the fish, transform into black spot metacercaria, and secrete a hyaline cyst around themselves. The host fish deposits black pigment around the cyst and the parasite is visible as a black spot. While it is understood that this parasite changes the behavior (reproductive and shoaling) of Gambusia, it is not clear how the Cercariae/Metacercaria life stage may sub-lethally affect other life history patterns. This project investigated the circulation rates of G. holbrooki with and without blackspot by observing red blood cells (RBC/min) within the central capillaries in the tail region of 40 total fish (30 without blackspot & 10 with blackspot) at 100X magnification. Results indicated a significant difference in RBC counts of fish afflicted with blackspot in comparison to G. holbrooki free of blackspot. This information can be used to better understand the physiological effects of blackspot on Mosquitofish and how its infestation may impact the fish’s ability to be an effective biocontrol.

 

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