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

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.     

Some features of the behaviour of the marbled newt Triturus marmoratus (Latreille, 1800) in captivity

The behaviour in groups of both sexes of marbled newts (Triturus marmoratus) from Sintra, Portugal, kept for a few weeks in a large aquarium, is described. Behaviour patterns described for this species and for other species in this genus were recognised. The following behaviours are described for the first time: Walk-over, Land-over, Stand-on, Show, Erect-body, Yawn, Circle, and Dig. Females seem to have a more active role in courtship than is usually considered. The behaviour frequencies for each sex were analysed using simulation statistics. Some elements usually classified as male sexual behaviours occur in both sexes and are likely to play other social roles. Received in revised form: 31 May 2001 Electronic Publication     

Observations on the agonistic behaviour of Lepadogaster lepadogaster purpurea (Pisces: Gobiesocidae)

Agonistic behaviour of captive Lepadogaster lepadogaster purpurea , was described, forming the first record of such behaviour in the family Gobiesocidae. Both male and female engaged in similar behaviours. The agonistic interactions were related mainly to the control of shelter sites and larger fish tended to chase away and take over the shelter of smaller fish.     

Cryptic speciation and genetic structure of widely distributed brittle stars (Ophiuroidea) in Europe

Pérez‐Portela, R., Almada, V. & Turon, X. (2012). Cryptic speciation and genetic structure of widely distributed brittle stars (Ophiuroidea) in Europe. —Zoologica Scripta, 00, 000–000. The development of molecular techniques has led to the detection of numerous cases of cryptic speciation within widely distributed marine invertebrate species and important taxonomic revisions in all the major marine taxa. In this study, we analysed a controversial marine species complex in the genus Ophiothrix, a widespread taxon in European waters traditionally assigned to two nominal species, Ophiothrix fragilis and O. quinquemaculata. These species are important components of the rocky shores and deep marine benthos along the North Atlantic and Mediterranean littoral. Their status (including variants of both species) has remained contentious due to overlapping variability in morphological characters. In this study, we analysed the genetic and morphological differences of Ophiothrix lineages along the Atlantic and Mediterranean coasts. We also assessed population genetic structure in the Atlantic and Mediterranean basins by sequencing two mitochondrial genes, the 16S rRNA gene and COI gene, of 221 specimens from 13 locations. Phylogenetic analyses demonstrated the existence of two genetically distinct lineages, attributable to two different species although unrelated to previous taxonomic distinctions. Morphological differences could also be detected between these lineages. Samples from the Northeast Atlantic and one from the deep Mediterranean grouped within Lineage I, whereas Lineage II pooled together the southern Atlantic and rocky shallow Mediterranean samples. In the northern region of the Iberian Peninsula and at a deep locality in the Mediterranean, both lineages overlap. Speciation processes likely happened during the Mio–Pliocene transition (about 4.8–7.5 million years ago), when marine‐level oscillations led to the blockage of major marine corridors in Europe and promoted genetic isolation by vicariance. Secondary contact between lineages following sea‐level increases and recolonization during the refilling of the Mediterranean after the Miocene salinity crisis could explain the present‐day distribution of genetic variability. No barriers to gene flow along the Atlanto‐Mediterranean area were detected for Lineage II, and the lack of genetic structure could be caused by a mixture of several factors, such as wide dispersal potential, recent demographic expansion and large population size.     

Male display characters, gonadal maturation and androgens in the cichlid fish Oreochromis mossambicus

  The relationships between gonadal maturation and the expression of behavioral and morphological display characters in O. mossambicus was investigated and the possible role of androgens in the coordination of this process was evaluated using genital papilla size as a bioassay for androgen levels. Morphological and behavioral displaying characters were found to be correlated among themselves. The sexually dimorphic characters were correlated with gonad maturation and androgen levels, but not with the gonado-somatic index. Gonad maturation and androgen levels were closely related. Territoriality and other behavioral variables involved in reproduction were also correlated with gonad maturation and androgen levels. These data suggest that in O. mossambicus androgens play a mediating role between gonadal maturation and the expression of display characters, both morphological and behavioral. Received: 23 February 1999 / Received in revised form: 3 May 1999 / Accepted: 10 May 1999     

Juveniles of non-resident fish found in sheltered rocky subtidal areas

Juvenile fishes of 22 species collected on a rocky shore area at Arrábida (Portugal) fell into three groups: (i) incidentals (four species); (ii) those in transit to a nearby estuary (three species); and (iii) nursery residents (15 species). For groups ii and iii this habitat seems to play an important role in their early life stages.