12 research outputs found

    Homing in rocky intertidal fish. Are Lipophrys pholis L. able to perform true navigation?

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    Although navigation is common in many animals, only a few perform true navigation, meaning that they have the ability to return to a given place by relying on indirect cues obtained at the release site (i.e., by relying on information from a ‘‘map and compass’’ mechanism). The common intertidal fish, Lipophrys pholis, is thought to have homing abilities through a mechanism that primarily makes use of familiar landmarks (i.e., piloting). Anecdotal reports that individuals return to their home pools after release at unfamiliar sites suggest that L. pholis might use cues collected at the release site to find their way back (i.e., they might use map and compass information). Using a completely artificial setup, we tested the homing abilities of L. pholis as a function of age, sex, and familiarity with the release site. The findings showed that motivation for homing is present only in the adult phase and is independent of sex and/or familiarity with the release site. Moreover, adults released at a completely unfamiliar place oriented themselves in a direction roughly similar to that of their home pools. The fact that L. pholis were tested in a complete artificial environment means that hydrodynamic cues can be excluded as playing a role in this process and restricts the candidate options (e.g., magnetic cues). The ability to perform navigation based on a ‘‘map and compass’’ mechanism raises many interesting questions about the learning process, once these individuals have restricted home ranges during their lives. In vertebrate navigation, the cues used during the navigation process are a question of debate, and L. pholis offers an outstanding model to test hypotheses and ultimately provide answers

    Molecular data confirm the validity of the portuguese blenny (Parablennius ruber, Valenciennes, 1836) and its presence in Western Europe

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    DNA sequence analysis confirms the distinction between Parablennius ruber and Parablennius gattorugine, simultaneously validating the presence of the former species in Western Europe where it has been reported for >150 years. A possible scenario involving speciation of P. ruber at the Azores and subsequent transport of larvae to Europe, a process that may be still occurring nowadays, could explain this pattern of occurrence

    Citizen science and expert judgement: A cost-efficient combination to monitor and assess the invasiveness of non-indigenous fish escapees

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    Mapping the distribution and evaluating the impacts of marine non-indigenous species (NIS) are two fundamental tasks for management purposes, yet they are often time consuming and expensive. This case study focuses on the NIS gilthead seabream Sparus aurata escaped from offshore farms in Madeira Island in order to test an innovative, cost-efficient combined approach to risk assessment and georeferenced dispersal data collection. Species invasiveness was screened using the Aquatic Species Invasiveness Screening Kit (AS-ISK), and revealed a high invasion risk. Occurrences of S. aurata were assessed involving citizens in GIS participatory mapping and data from recreational fishing contests. A probability map showed that S. aurata is well dispersed around Madeira Island. This assessment proved to be a cost-efficient early warning method for detecting NIS dispersal, highlighting the urgent need for additional surveys that should search for sexually mature individuals and assess the direct and indirect impacts in the native ecosystemFundação para a Ciência e Tecnologia - FCTinfo:eu-repo/semantics/publishedVersio

    Breves considerações sobre a eco-etologia de Lypophrys trigloides (Pisces : Blenniidae)

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    Dissertação de Mestrado em Etologi

    Molecular validation of the specific status of Parablennius sanguinolentus and Parablennius parvicornis (Pisces: Blenniidae)

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    Parablennius sanguinolentus and P. parvicornis have been classified as either two distinct species or as two sub-species depending on the different criteria used to classify them. An analysis of fragments of mitochondrial 12S and 16S rDNA showed that the genetic distance between samples of P. sanguinolentus and P. parvicornis is similar or higher than those found for other blenniids that are widely recognized as distinct species. These results, together with the distinct geographical distributions and meristic differences, support the conclusion that P. sanguinolentus and P. parvicornis should be considered as two different species

    Agonistic behaviour and sound production in Gaidropsarus mediterraneus, (Gadidae)

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    Agonistic behaviour and sound production were described for captive Gaidropsarus mediterraneus, a shore-dwelling gadoid. Thump-like sounds were produced during agonistic interactions, which involved disputes over access to shelter sites

    Home sweet home: evidence for nest-fidelity in the rocky intertidal fish, the shanny Lipophrys pholis

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    The ability to be faithful to a particular area or site was analysed in the shanny Lipophrys pholis. Using passive integrated transponders, adults from a population of L. pholis at Cabo Raso, Portugal, were followed over a period of 3 years. The findings showed that site fidelity is a consistent behaviour during the breeding season with specific breeding males being found only in particular sectors within the area, and in specific nests throughout the years. The fact that, in general, L. pholis individuals were absent from the study area during the non-breeding season and breeding males were recorded returning to the same nests and sectors for consecutive breeding seasons suggests that they have developed excellent homing abilities. Translocation data corroborate this idea showing that breeding males successfully returned to their nests after a displacement of >100 m. Altogether, these findings highlight the relevance of life-history traits (e.g. nesting) in the conditioning of site fidelity and homing for this species of rocky intertidal fish, and more importantly, provide evidence for the need of a well-developed navigational system.Fundação para a Ciência e a Tecnologia (FCT

    On the absence of genetic differentiation between morphotypes of the ballan wrasse Labrus bergylta (Labridae)

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    The ballan wrasse, Labrus bergylta (Labridae), is a protogynous hermaphrodite fish common in the north-eastern Atlantic from Norway to Morocco. It is a commercially important resource for local fisheries and is currently being used as cleaner fish to control sea lice in salmon farms in northern Europe. Two distinct colour patterns have been recently reported in the literature: plain and spotted. These individuals follow strikingly different life history strategies raising the question of whether they represent one or two independent taxonomic units. Analyses of mitochondrial (18S, COI and control region) and nuclear (S7) markers revealed no genetic differences between these morphotypes. Alternative explanations for the origin and persistence of distinct morphotypes are discussed.Fundação para a Ciência e a Tecnologia (FCT); European Commissio
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