Echiodon prionodon, a new species of Carapidae (Pisces, Ophidiiformes) from New Zealand

peer reviewedA new species of pearlfish, Echiodon prionodon, is described from three specimens. This species is diagnosed by having a serrated margin on the posterior edge of the fangs, expanded thoracic plates on some abdominal vertebrae and ventral swimbladder tunic ridges. This species was only found in coastal waters around the North Island of New Zealand. The diagnosis of Eurypleuron is revised

Chapter 3- Mechanisms of Fish Sound Production

peer reviewe

Encheliophis chardewalli: A new species of carapidae (Ophidiiformes) from French Polynesia, with a redescription of Encheliophis vermicularis

A specimen of Encheliophis was found in the coelomic cavity of a sea cucumber in Moorea (French Polynesia). The skeletal morphology (skull, girdles, vertebrae) reveal it to be a new species, described herein as Encheliophis chardewalli. It is separable from all described species of Encheliophis (except Encheliophis vermicularis) by the lack of pectoral fins and from E. vermicularis by the larger and fewer teeth on the lower jaw (14 vs more than 20 in E. vermicularis) and by seven branchiostegal rays (vs six in E. vermicularis).Peer reviewe

Relationships between inner ear and sagitta growth during ontogenesis of three Carapini species, and consequences of life-history events on the otolith microstructure

Three species of Carapidae have in common a tenuis larval stage, during which they settle in the lagoon and take refuge in the same species of holothurold. From the juvenile stage, Carapus homei and C. boraborensis are commensal, whereas Encheliophis gracilis is parasitic. The aims of this study were to analyse to what extent the ontogenctic changes of the otic capsule affected the shape of the inner ear and how environmental cues, due to the above-mentioned life history and the style, could influence the structure of the sagitta. Sagittal sections revealed a three-dimensional asymmetry with a nucleus close to the proximal surface. Observations of the growth axis of the sagitta suggest it has a morphogenetic impact on the otic cavity. Each sagitta contains three main zones related to the life stages of the fish. Bands and checks were observed in the third zone in C. homei and C. boraborensis, but this pattern was less discernible in E. gracilis. These structural differences in zone 3 could be related to the commensal and parasitic life styles of these fishes. Further studies dealing with otosac features and otolith functions are suggested.Peer reviewe

Fin flickering and associated sounds in the cichlid fish Ophthalmotilapia ventralis: a preliminary study.

Fin flickering was defined as rapid movements of the fins. The behavioral function of such movements is however not well established. Depending on the species investigated, they were considered as comfort movements (e.g. removal of minor irritations) or alarm for young. In the cichlid Etroplus maculatus they allow homogenous repartition of eggs on the substrate. We studied visual and acoustical behavior of five Ophthalmotilapia ventralis (two males and three females) reared in a 240 l tank. Pectoral fin flickering associated with sound production was often observed, especially from fish that established a territory. With the exception of the butterflish Chaetodon mutlicinctus and gouramis, this aspect of fin flickering is generally overlooked in teleosts. First observations support the fact that sounds (peak frequency and pulse duration: 562±95 Hz and 14±5 ms, respectively) are not emitted during all kinds of fin movements but mainly during some caudo-rostral horizontal fin sweeps. In-depth studies are however required to better characterize the movements and understand what morphological traits are responsible for the sound production. Further investigations are also needed to determine if fin flickering has a role in O. ventralis social interaction

Insight into biting diversity to capture benthic prey in damselfishes (Pomacentridae)

peer reviewedThe cerato-mandibular (c-md) ligament, joining the hyoid bar to the coronoid process of the angular, allows Pomacentridae to slam their mouth shut in a few milliseconds. Previous works have revealed that such a mechanism is used to feed, but some variability in biting patterns has been observed between two damselfish species. The pelagic feeder Amphiprion clarkii performs two different kinematic patterns to bite fixed prey, one that does not depend on the c-md ligament (biting-1) and one that does (biting-2). The benthic feeder Stegastes rectifraenum only performs biting-2. The present study aims to shed light on the occurrence of biting-2 in the feeding behaviour of Pomacentridae. To test our hypothesis that biting-2 would be the only biting pattern for benthic feeders, we compared biting behaviours among four species: one pelagic feeder, A. clarkii, and three benthic feeders, Neoglyphidodon nigroris, Stegastes leucostictus and S. rectifraenum. Our results showed that the four species were able to perform biting-2, but they do not support that the use of this pattern is related to trophic habits. Contrary to S. rectifraenum, the two other benthic feeders randomly used biting-1 and biting-2 patterns, similar to A. clarkii. Two hypotheses are discussed for explaining this variability within Pomacentridae. Finally, it has been recently shown that some damselfishes do not possess the c-md ligament. We therefore included two species lacking the c-md ligament (Chromis chromis and Abudefduf troschelii) in our study and we demonstrate our expectation that they are unable to perform biting-2

A preliminary study of development of the buccal apparatus in Pomacentridae (Teleostei, Perciformes)

This study compares, in five species of Pomacentridae (Chromis viridis, Dascyllus flavicaudus, Chrysiptera glauca, Pomacentrus pavo, Plectroglyphidodon lacrymatus), the changes in cephalic skeletal structures between settling larvae and adults living on the reef. Variations were studied in the suspensorium, the opercle, the mandible, the premaxillary bone and the teeth. Comparisons of the feeding apparatus enabled two different types of feeding to be distinguished in adults: suction feeding and grazer sucking. Adult C. viridis and D. flavicaudus have a high suspensorium, a well-rounded mouth during jaw opening and caniniform teeth. These two species can be considered to be suction feeders. On the other hand, adult C glauca, P pavo and P lacrymatus have less developed suspensoria, opercles and ascending process of the premaxillar, and present incisiform teeth. These three species appear to be grazer suckers. However, the larvae of all five species present an unimodal way of feeding, defined as ram-suction. Differences between larvae and adults appear clearly to be related to their ecology. The increasing variation presented in feeding apparatus during the settlement phase could be linked to diversification leading to occupancy of different ecological niches.Peer reviewe

Trophic specializations of damselfishes are tightly associated with reef habitats and social behaviours

peer reviewedDespite the increasing need to understand factors shaping community assembly, few studies have simultaneously explored the influence of niche-based and phylogenetic processes. Here, we investigate the relationships between diet, habitat and social behaviour in damselfishes (Pomacentridae) collected in 2014 at Moorea Island (17°30′S, 149°50′W), French Polynesia. Isotope ratios of carbon and nitrogen, in association with stomach contents, delineate three trophic groups: pelagic feeders consuming zooplankton, benthic feeders mainly grazing on algae and an intermediate group feeding on prey from the whole bentho-pelagic compartment. Sulphur isotope ratios indicate segregation between species of the outer reef mostly depending on oceanic input of zooplankton and the lagoonal species relying on locally produced resources or even on terrestrial supply. We demonstrate a tight association between dietary specializations, habitat characteristics and social behaviours, and these correlations are further confirmed by integrating the phylogeny of Pomacentridae. We also provide evidence of phylogenetic conservatism for the stomach content and the habitat–behaviour characters. However, the isotopic trait is evolutionarily more labile probably because it thoroughly depicts the ecological niche of species. To summarize, pelagic feeders (mainly from the Chrominae) usually form shoals in areas close to the open ocean at a maximum depth of 20 m. Benthic feeders (well represented in the Stegastinae) are ubiquitous, solitary and mostly territorial species found at various depths. The intermediate group includes gregarious species from three subfamilies that forage in the lagoon usually above 12 m depth. Overall, we give insight into processes that have structured the damselfish community in Moorea