Bromeliad treefrogs as phoretic hosts of ostracods

Area of Science:

• Ecology
• Zoology
• Freshwater Biology

Background:

• Phoresy, a dispersal mechanism where one organism attaches to another for transport, is crucial for aquatic invertebrates colonizing isolated habitats.
• Tank bromeliads represent unique microhabitats supporting diverse fauna, including ostracods, which rely on dispersal strategies like phoresy.
• Treefrogs have been identified as potential phoretic hosts for aquatic organisms, facilitating their movement between discrete water bodies.

Purpose of the Study:

• To investigate the distribution patterns of phoretic ostracods on treefrog hosts.
• To compare ostracod prevalence and intensity between different treefrog species (Scinax littoreus and Scinax perpusillus).
• To assess seasonal variations in ostracod abundance on treefrogs in Brazil.

Main Methods:

• Field surveys were conducted in Rio de Janeiro State, Brazil, focusing on two inselberg areas.
• Ostracod distribution was analyzed across various body parts of collected treefrogs.
• Prevalence and intensity of ostracod infestation were quantified and compared between treefrog species and across wet and dry seasons.

Main Results:

• Significant differences in ostracod distribution were observed among treefrog body parts and between the two Scinax species.
• Elpidium sp. (ostracod) abundance on Scinax littoreus was significantly higher during the wet season compared to the dry season.
• Scinax cuspidatus and Thoropa miliaris were identified as novel phoretic hosts for Elpidium sp.

Conclusions:

• Treefrogs are effective phoretic hosts for ostracod dispersal, with host specificity and body part distribution playing key roles.
• Seasonal environmental conditions, particularly rainfall, influence ostracod abundance on certain treefrog species.
• The study expands the known host range for Elpidium sp. phoresy, highlighting the ecological interactions within bromeliad ecosystems.