The larval stage is the main dispersive mechanism of most marine teleost fish species. The degree... more The larval stage is the main dispersive mechanism of most marine teleost fish species. The degree to which larval behavior controls dispersal outcome has been a subject of debate in the past decades. Multiple studies demonstrated orientation mechanisms in several species separately, however a cross-species analysis examining fundamental orientation traits has not been carried out. Here, we apply a cross-species meta-analysis, focusing on the fundamental question of whether larval fish use external cues for directional movement. We compare the observed directional patterns to those expected under a strict use of internal cues. We find that the bulk of fish larvae use external cues for directional swimming, highlighting the contribution of larval orientation behavior to larval dispersal outcome. This finding is an essential step towards a proper implementation of larval behavior in biophysical dispersal models, improving our understanding of population connectivity, and facilitating s...
Animals often change their habitat throughout ontogeny; yet, the triggers for habitat transitions... more Animals often change their habitat throughout ontogeny; yet, the triggers for habitat transitions and how these correlate with developmental changes – e.g. physiological, morphological, and behavioural – remain largely unknown. Here, we investigated how ontogenetic changes in body colouration and of the visual system relate to habitat transitions in a coral-reef fish. Adult dusky dottybacks, Pseudochromis fuscus, are aggressive mimics that change colour to imitate various fishes in their surroundings; however, little is known about the early life stages of this fish. Using a developmental time-series in combination with the examination of wild caught specimens we uncover that dottybacks change colour twice during development: (i) nearly translucent cryptic pelagic larvae change to a grey camouflage colouration when settling on coral reefs; and (ii) juveniles change to mimic yellow or brown coloured fishes when reaching a size capable of consuming juvenile fish prey. Moreover, micros...
Wrasses (Labridae) are the second largest family of ¢shes on the Great Barrier Reef (after the Go... more Wrasses (Labridae) are the second largest family of ¢shes on the Great Barrier Reef (after the Gobiidae) and, in terms of morphology and lifestyle, one of the most diverse. They occupy all zones of the reef from the very shallow reef £ats to deep slopes, feeding on a variety of fauna. Many wrasses also have elabo-rately patterned bodies and re£ect a range of colours from ultraviolet (UV) to far red. As a ¢rst step to investigating the visual system of these ¢shes we measured the transmission properties of the ocular media of 36 species from the Great Barrier Reef, Australia, and Hawaii, California and the Florida Keys, USA. Transmission measurements were made of whole eyes with a window cut into the back, and also of isolated lenses and corneas. Based on the transmission properties of the corneas the species could be split into two distinct groups within which the exact wavelength of the cut-o ¡ was variable. One group had visibly yellow corneas, while the corneas of the other group...
concepts, previous attempts to teach fish have been unsuccessful. In this report, the ability of ... more concepts, previous attempts to teach fish have been unsuccessful. In this report, the ability of archerfish (Toxotes chatareus) to learn the concepts of sameness and difference using a simultaneous two-item discrimination task was tested. Six archerfish were trained to either select a pair of same or different stimuli which were presented simultaneously. Training con-sisted of a 2-phase approach. Training phase 1: the symbols in the same and different pair did not change, thereby allowing the fish to solve the test through direct association. The fish were trained consecutively with four different sets of stimuli to familiarize them with the general procedure before moving on to the next training phase. Training phase 2: six differ-ent symbols were used to form the same or different pairs. After acquisition, same/different concept learning was tested by presenting fish with six novel stimuli (transfer test). Five fish successfully completed the first training phase. Only one individ...
The larval stage is the main dispersive mechanism of most marine teleost fish species. The degree... more The larval stage is the main dispersive mechanism of most marine teleost fish species. The degree to which larval behavior controls dispersal outcome has been a subject of debate in the past decades. Multiple studies demonstrated orientation mechanisms in several species separately, however a cross-species analysis examining fundamental orientation traits has not been carried out. Here, we apply a cross-species meta-analysis, focusing on the fundamental question of whether larval fish use external cues for directional movement. We compare the observed directional patterns to those expected under a strict use of internal cues. We find that the bulk of fish larvae use external cues for directional swimming, highlighting the contribution of larval orientation behavior to larval dispersal outcome. This finding is an essential step towards a proper implementation of larval behavior in biophysical dispersal models, improving our understanding of population connectivity, and facilitating s...
Animals often change their habitat throughout ontogeny; yet, the triggers for habitat transitions... more Animals often change their habitat throughout ontogeny; yet, the triggers for habitat transitions and how these correlate with developmental changes – e.g. physiological, morphological, and behavioural – remain largely unknown. Here, we investigated how ontogenetic changes in body colouration and of the visual system relate to habitat transitions in a coral-reef fish. Adult dusky dottybacks, Pseudochromis fuscus, are aggressive mimics that change colour to imitate various fishes in their surroundings; however, little is known about the early life stages of this fish. Using a developmental time-series in combination with the examination of wild caught specimens we uncover that dottybacks change colour twice during development: (i) nearly translucent cryptic pelagic larvae change to a grey camouflage colouration when settling on coral reefs; and (ii) juveniles change to mimic yellow or brown coloured fishes when reaching a size capable of consuming juvenile fish prey. Moreover, micros...
Wrasses (Labridae) are the second largest family of ¢shes on the Great Barrier Reef (after the Go... more Wrasses (Labridae) are the second largest family of ¢shes on the Great Barrier Reef (after the Gobiidae) and, in terms of morphology and lifestyle, one of the most diverse. They occupy all zones of the reef from the very shallow reef £ats to deep slopes, feeding on a variety of fauna. Many wrasses also have elabo-rately patterned bodies and re£ect a range of colours from ultraviolet (UV) to far red. As a ¢rst step to investigating the visual system of these ¢shes we measured the transmission properties of the ocular media of 36 species from the Great Barrier Reef, Australia, and Hawaii, California and the Florida Keys, USA. Transmission measurements were made of whole eyes with a window cut into the back, and also of isolated lenses and corneas. Based on the transmission properties of the corneas the species could be split into two distinct groups within which the exact wavelength of the cut-o ¡ was variable. One group had visibly yellow corneas, while the corneas of the other group...
concepts, previous attempts to teach fish have been unsuccessful. In this report, the ability of ... more concepts, previous attempts to teach fish have been unsuccessful. In this report, the ability of archerfish (Toxotes chatareus) to learn the concepts of sameness and difference using a simultaneous two-item discrimination task was tested. Six archerfish were trained to either select a pair of same or different stimuli which were presented simultaneously. Training con-sisted of a 2-phase approach. Training phase 1: the symbols in the same and different pair did not change, thereby allowing the fish to solve the test through direct association. The fish were trained consecutively with four different sets of stimuli to familiarize them with the general procedure before moving on to the next training phase. Training phase 2: six differ-ent symbols were used to form the same or different pairs. After acquisition, same/different concept learning was tested by presenting fish with six novel stimuli (transfer test). Five fish successfully completed the first training phase. Only one individ...
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