Blog Post #1 – 6/21/22

Collecting Coqui Frogs – Maui edition

coqui frog
Male coqui frog with extended vocal sac.

June 21, 2022

The Longo Lab recently visited the island of Maui, HI to collect coqui frogs for our experimental work without impacting natural populations in Puerto Rico. We study how coqui frogs use their skin microbiome to fight infectious diseases. Invasive coqui frogs in the Hawaiian Islands are closely related to coquis from populations in northeastern Puerto Rico. Therefore, our inferences from Hawaiian coqui frogs will be applicable to their counterparts in Puerto Rico.

Our time in Maui was very productive. We learned about the control programs carried out by the Maui Species Committee and participated in one of the citric acid applications. The committee has done an impressive amount of work to control coqui populations in the island of Maui.

Each night after dark, we looked for coqui frogs among the vegetation at a site in Haiku. We spotted frogs with a flashlight, collected each frog by hand, and placed them inside plastic bags. Our carrying bags got full within 1-2hrs! Frogs were calling everywhere!

Each frog was inspected and sexed. We measured its body size and weight and recorded the data. This type of baseline data allows us to determine growth rates and any potential deficits in their diets that need supplementation.

We keep all frogs individually–from capture until the end of the experiment–to avoid transmission of pathogens. Their containers consist of 5.5oz deli cups packed with sphagnum moss and holes for aeration. Researchers have shown that coqui frogs in Hawaii are infected with the amphibian chytrid fungus (Batrachochytrium dendrobatidis) and also with parasites such as the rat lungworm (Angiostrongylus cantonensis). We checked the frogs every day, spray them with water until they were shipped via Fedex. Every 3 days we fed them crickets bought at local pet store.

The coqui gods were in our favor! All the animals safely arrived at their destination at the University of Florida. We keep coqui frogs inside incubators with controlled temperature and humidity. We provide PVC tubes as a hiding place.

We are really excited to start our experiments in the lab. Right now, the frogs are in the process of acclimating to their enclosures and the new temperatures/humidity regimes. We will be testing if there is a genetic basis underlying the seasonal transitions when frogs are infected with the pathogenic fungus Batrachochytrium dendrobatidis (Bd). In addition, we will expose frogs to bacterial symbionts isolated from Puerto Rican coquis to test to understand how microbial diversity facilitates the recovery after Bd infection.

Postdoc María Torres-Sánchez and Zuania Colón-Piñeiro are leading these efforts with the help of our undergraduate student Anja Julian. Arik Hartmann helped us out collecting frogs, swabbing, and packing them for their long journey to UF.

More updates soon!

Ana & the Longo Lab

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