Habitat Preference of the Gulf Toadfish Opsanus beta

• In Event: Marine Science Oral Session & Section Meeting

Abstract

Studies have shown that much is known about the metabolic plasticity of the Gulf toadfish, Opsanis beta, but little is known regarding their natural history. It is likely that toadfish are top predators in seagrass ecosystems. Since little is known about this aspect of toadfish, I aim to investigate and to better understand the habitat preferences of Gulf toadfish in Red Fish Bay, Texas. In a series of three experiments, I tested habitat preference of small, medium, and large toadfish. In the first field experiment, we tested habitat preferences in the field of the larger toadfish in plastic mesocosms (kiddy pools). These mesocosms consisted of a sand/mud mix bottom, 1/3 sand, 1/3 Halodule, and 1/3 Thalassia. Initial positions were recorded, and after one hour their position was recorded again. The bigger individuals were tagged with a plastic visual elastomer before being released. Smaller toadfish were brought back to the lab. In the lab, tubs were set up and randomly assigned 1/3 Halodule, 1/3 Thalassia, and sand. Both one hour and twenty-four hour observations occurred. Similar to the procedure in the field, initial, after one hour, and final position were recorded. The results showed that the toadfish do have a habitat preference for Halodule vegetation. There was no significant difference between their positions at 1 and 24 hours. Knowing more about where and how this particular species interacts within the ecosystem they live in can be beneficial to understanding the habitat requirements of a potentially important keystone predator in grass bed ecosystems.

Author

• Claire Adams, St. Edward's University