Coloration of Anuran Tadpoles (Amphibia): Development, Dynamics, Function, and Hypotheses

Abstract

Colorations of anuran tadpoles surely function in many of the same ways that have been ascribed to color and pattern in other animals, but the paucity of data forces one to look to other groups to generate hypotheses. Such an action often occurs because of the difficulty of defining specific fitness parameters to larval forms. The commonly muted colorations of tadpoles are typically considered to function only in some form of crypsis, but we discuss other functions in the particular context of behavioral ecology and changes induced by various kinds of coinhabitants. We review the development, terminology, diversity, and functions of coloration in tadpoles and then pose various questions for future research. We strongly support a broad-based perspective that calls for an integration of several fields of research.

The Tadpole ofBokermannohyla flavopictaLeite, Pezzuti and Garcia, 2012 and Oral Cavity Anatomy of the Tadpole ofB. oxenteLugli and Haddad, 2006 (Anura: Hylidae)

“…Although coloration can vary according to pond conditions, predator density, and ontogeny (Thibaudeau and Altig, 2012), we observed that living and fixed B. flavopicta tadpoles in all development stages do not exhibit black dots (melanophores) distributed along the body surface, as observed in most tadpoles in the B. pseudopseudis group (see Fig. 5 for B. itapoty and B. oxente tadpoles) except B. ibitiguara and B. saxicola (Cardoso, 1983;Eterovick and Brandão, 2001).…”

Pigmentation plasticity enhances crypsis in larval newts: associated metabolic cost and background choice behaviour

“…, the light absorbing organelles) can be reallocated in the melanophores ( i.e. , a type of pigment cells within the dermal chromatophore unit), resulting in a lightening (pigment aggregation) or darkening (pigment dispersion) of the skin323334353637. Although these colour shifts are not instantaneous as those exhibited by chameleons, flatfish or cephalopods383940, both larvae and adults of many amphibian species benefit from relatively rapid ( i.e.…”

“…The vast majority of studies on amphibian camouflage have focused on anurans283334375960 (see ref. 61 for an extensive review), whereas the adaptive value of cryptic coloration and behaviour of salamanders –aside from their aposematic traits626364– has received considerably less investigation.…”

Extreme colour variation in the larvae of the executioner clownfrog, Dendropsophus carnifex (Anura: Hylidae), living in nearby ponds of different light exposure and duration

“…Cott, ; Fogden & Fogden, ; Rudh & Qvarnström, ; Arbuckle & Speed, ). In tadpoles, body coloration serves many functions, such as crypsis, thermoregulation, ultraviolet protection and communication (Thibaudeau & Altig, ). Diversity of coloration in tadpoles is not limited to genetic variation among species or populations, but may also be a product of plasticity and environmentally induced changes resulting from ecological conditions such as light regimes, turbidity, coloration of the environment (water or background), the presence of predators, temperature and UV‐B radiation (Rudh & Qvarnstöm, ).…”

“…Diversity of coloration in tadpoles is not limited to genetic variation among species or populations, but may also be a product of plasticity and environmentally induced changes resulting from ecological conditions such as light regimes, turbidity, coloration of the environment (water or background), the presence of predators, temperature and UV‐B radiation (Rudh & Qvarnstöm, ). For instance, tadpoles inhabiting turbid water often look pale, while conspecifics living in tannin‐stained water are frequently brightly coloured (Thibaudeau & Altig, ). In response to predator presence, coloration may change to either enhance background matching, improve camouflage through disruptive coloration (Polo‐Cavia & Gomez‐Mestre, ), or promote bright colours on expendable body parts in order to lure predators away from vital areas (Touchon & Warkentin, ).…”