Banca de QUALIFICAÇÃO: DIOGO JACKSON DE AQUINO SILVA

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
STUDENT : DIOGO JACKSON DE AQUINO SILVA
DATE: 30/01/2023
TIME: 10:00
LOCAL: Online
TITLE:

Visual communication in fiddler crabs: effects of coloration on sociosexual signaling and predation

KEY WORDS:

Body coloring; Camouflage; Decoy; reproductive maturity; Color vision

PAGES: 71
BIG AREA: Ciências Biológicas
AREA: Zoologia
SUBÁREA: Comportamento Animal
SUMMARY:

Courtship and competition behaviors of fiddler crabs are mediated by conspicuous visual cues from the male's claw, which reflects its quality through size, strength, and wave speed. Signaling to conspecifics, however, has a cost associated with attracting predators, which is mitigated through anti-predation strategies, such as camouflage, aposematism, or decoys. The objective of this study is to evaluate whether the fiddler crab’s body coloration is adapted to their habitat to optimize their visual signaling for conspecifics and reduce predation costs through camouflage or decoy. Through spectrophotometric analysis and visual modeling of a community composed by five species of fiddler crabs (Leptuca leptodactyla, Leptuca cumulanta, Leptuca thayeri, Minuca rapax, and Uca maracoani), we seek to know if their body colors have a pattern of conspicuity in the claw and camouflage in the carapace. We study the intraspecific signaling of the species L. leptodactyla through laboratory and behavioral experiments seeking to answer whether honest color signaling is related to size, strength, and reproductive maturity. In addition, field predation experiments will be carried out using fiddler crabs’ models to verify the predation pressure on different cryptic and conspicuous phenotypes. The partial results show us that, through the ecology and visual modeling of the five species, the claws are more conspicuous than their carapaces. Furthermore, we saw that there are no differences in individual quality (claw color, claw type, size, weight, and strength) between males of cryptic and conspicuous phenotypes. The color phenotype may be linked to survival capacity, which will be tested by the predation and camouflage experiment. There are no visual differences between original and regenerated claws, but there are differences in weight and strength, which configures a dishonest sign. These partial results show us that the conspicuous claw coloration, while it was developed to attract reproductive partners, was selected to attract the attention of predators to avoid an attack on the carapace, a vital region.

COMMITTEE MEMBERS:
Presidente - 1476621 - DANIEL MARQUES DE ALMEIDA PESSOA
Externa à Instituição - TÂNIA MARCIA COSTA - UNESP
Externo à Instituição - VINÍCIUS DE AVELAR SÃO PEDRO - UFSCAR