Digging with 'hands': observations of food capture in the flying gurnard Dactylopterus volitans (Linnaeusı 1758)
| Autor: | Peter Wirtz, John Davenport |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
0106 biological sciences
Flying gurnard Dactylopteridae biology Foraging 6-legged walking 010607 zoology Biodiversity biology.organism_classification Searobin 010603 evolutionary biology 01 natural sciences Fishery Digging Geography Fish Flying gurnards Digging for prey Pectoral fin 'hands' 14. Life underwater Syngnathiformes Ecology Evolution Behavior and Systematics Taxonomy |
| Zdroj: | Repositório Científico de Acesso Aberto de Portugal Repositório Científico de Acesso Aberto de Portugal (RCAAP) instacron:RCAAP |
| Popis: | Videofilms of a foraging flying gurnard (Dactylopterus volitans) were collected at Itaipu, Niteroi, RJ, Brazil. Analysis revealed details of the use of anterior parts of the pectoral fins which act as digging 'hands' to access infaunal prey items that are subsequently captured by oral suction feeding. Each pectoral fin has two distinct sections articulated separately on the pectoral girdle. The digging 'anterior pectoral fin' mainly consists of segmented and flexible fin rays but has an anterior robust unsegmented ray that provides an edge to the 'hand', allowing penetration of the substratum. The huge 'posterior pectoral fins' are supported by unsegmented rays. Most digging episodes involved one 'hand' and consisted of 1-7 cycles of movement with frequencies 1.15-3.74 cycles s(-1). During a cycle, the 'hand' is moved forwards and medially above the substratum, then is twisted medially and simultaneously depressed so that the anterior unsegmented ray impacts and enters the substratum. The hand is then drawn backwards and laterally to disturb the substratum. To prevent upward pitching of the head during digging, the 'posterior pectoral fins' are both moved anteriorly and laterally to shift the centre of gravity forwards while the caudal and second dorsal fins continue to provide propulsive force. info:eu-repo/semantics/publishedVersion |
| Databáze: | OpenAIRE |
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