The diurnal aggregation behavior in Phasmahyla cochranae tadpoles (Anura: Hylidae)

Abstract

We investigated schooling behavior of Phasm ahyla cochranae including its periodicity based on periodic regression models. The school structure and differences between day and night were discussed. We found that tadpoles formed aggregative schools, which were significantly more frequent during the day than at night. During the day, from 06:30 to 18:00 h, tadpoles formed one or two polarized schools at the water surface. Based on these results and on observations of specific behaviors, we suggest that daylight may be a significant environmental factor related to schooling behavior in P. cochranae, although this hypothesis needs to be further investigated.

Effects of the presence of litter on the composition of stream tadpoles' assemblages in an Atlantic Forest remnant of southeastern Brazil

“…Apart from daylight, tadpole aggregation behavior is linked to water transparency, temperature, and other characteristics not investigated in the present study (Branch 1983, Spieler 2003. However, it is known that tadpoles of P. cochranae and S. obtriangulatus are more active during the day (Carvalhoe-Silva 1986, Leão-Pires et al 2017. Behavior shift can also be a strategy to avoid overlapping and interspecific competition as well to assure protection against predators (Carlson & Langkilde 2013).…”

“…Puddle depth did not influence the occurrence of Phasmahyla nordestinus tadpoles, suggesting a strategy to avoid competition or a response to unpredictable temporary aquatics habitats, limiting the degree of specialization for resources in the Brazilian semi-arid, an environment subjected to water scarcity and irregularities (Caldas et al 2019). Phasmahyla cochranae tadpoles present schooling and aggregation behavior associated with daylight (Leão-Pires et al 2017). In the present study, only two tadpoles of P. cochranae were captured and on different occasions, which is easily explained by the fact that the traps were set at the bottom of the stream, reducing the probability of capturing non-benthic tadpoles.…”