Popularly known as blue land crab, Cardisoma guanhumi is heavily exploited as food and considered as an important economic resource in Brazil. In recent decades, the species has experienced a sharp population decline by the loss and/or degradation of its natural habitat and overfishing. The present study aimed to investigate the genetic variation and connectivity among 154 specimens of C. guanhumi sampled along the coast of Pernambuco in five different levels of tropical mangroves conservation. Nine ISSR primers were used for assessing the genetic variation of the species. The genetic diversity observed in C. guanhumi was high reinforcing the condition of a resilient species, indicating a good conservation status of this resource in Pernambuco. The hypothesis of panmixia was rejected in favour of a heterogeneous distribution of the genotypes of C. guanhumi (ФST = 0.19) despite the high gene flow observed in the study region. Such difference could be attributed to the candidate loci being under positive selection and differentially distributed between the geographic regions assessed. The genetic structure showed a pattern of fine-scale genetic structuring better fitted to a model of selection-mediated geographic cline. Cluster analysis and candidate loci under positive selection suggested that the populations of C. guanhumi in the North-central and South coasts of Pernambuco might be different management units and must be managed independently. In conclusion, exhaustion of natural stocks upon which fishing is totally dependent will lead to serious ecological and sociocultural impacts.

To study some early life history traits of Lipophrys pholis, 110 recruits (TL ≤ 30 mm) were collected in April and May 2013 during the low tide periods in four rocky beaches along the west (Cabo do Mundo, Peniche and Vale do Homem) and south (Olhos de Água) Portuguese coasts. Pelagic larval duration, size at settlement and age at coastal recruitment were back-calculated from the microstructure of otoliths. Pelagic larval duration estimated from micro-increment counts until the settlement marks ranged from 57 to 73 days and showed a latitudinal reduction trend from north to south. This variable seems to be related in 30% with the regional seawater temperatures probably through the direct effect on the somatic growth. Settlement sizes (~19 mm) did not show any regional differences suggesting that this is a more conservative character within species. The mean age at coastal recruitment varied between 69 and 93 days, but northern individuals were recruited at an older age. Back-calculated spawning, hatching and settlement dates appear to be unrelated to the lunar cycle for L. pholis.

Two new species are described from the Patagonia coast of Argentina, South Atlantic, and written keys to both genera are given. Chaetonema patagonica sp. nov. can most easily be differentiated from the other four species of the genus by the amphid shape and by the absence of a precloacal organ. Admirandus sanjuliensis sp. nov. is characterized by position of the Demanian pores, one preanal and two postanal, the configuration of pre- and postcloacal papillae and setae and by having the shortest stoma in the genus.

Nebalia dolsandoensis sp. nov. (Malacostraca: Phyllocarida: Leptostraca), is described from specimens taken from light traps in harbours with organic-rich muddy sand and seaweeds along the south coast of Korea. The new species is characterized based on the following unique combination of characteristics: an antennular flagellum with up to only nine articles in the mature female; the fourth article of the antennule has up to four distal spine-like setae; pleonites 3–7 have rounded denticles along the posterior dorsal margins; the protopod of pleopod 4 has an even posterior margin; the uropods are distinctly short, about 0.6 times as long as pleonite 7 and the anal somite combined; the anal plates have a noticeably broad lateral ‘shoulder’. In addition, a key to the species of the genus Nebalia Leach, 1814 and partial sequences of the mitochondrial cytochrome c oxidase subunit 1 (CO1) gene from the new species are provided.

Changes in the planktonic cyanobacteria structure, composition and diversity were followed over three consecutive years (2005–2006–2007) in the Gulf of Gabes (Eastern Mediterranean Sea, Tunisia). Cyanobacteria abundances, biomasses and cell lengths were measured together with selected environmental variables (pH, salinity, temperature and nutrients). The space and time variations of the cyanobacteria in relation to the environmental factors showed a close relationship between these plankton communities and the hydrographic structure of the water column. Cyanobacteria developed over semi-mixed conditions (May–June 2006) and during the thermal stratification (July 2005). The cyanobacterial abundance and biomass was evident between 20 and 35 m in inshore stations and between 20 and 25 m in deeper stations during the semi-mixing conditions and stratification. This thermocline level coincided with the euphotic layer (21.85 ± 3.76 m) allowing access of light radiation. The cyanobacteria bloom occurred during May–June 2006 when the N/P ratio (<10) was clearly below the accepted standard molar ratio of N/P = 16/1. Commonalities among cyanobacterial genera include being highly competitive for low concentrations of inorganic P (DIP) and the ability to acquire organic P compounds. Our study showed that both diazotrophic (N2-fixing) cyanobacteria such as Anabaena sp., Chroococcus sp., Trichodesmium erythraeum, Spirulina sp. and Spirulina subsalsa and non-diazotrophic cyanobacteria such as Pseudoanabaena sp. and Microcystis display a great flexibility in the N sources which allow formation of blooms.

The members of the heat shock protein 70 ( HSP70) family are among the most conserved and widely studied stress proteins. The transcription and translation levels of HSP70 genes have also been studied in several marine and freshwater sponges as molecular markers to characterize the response of sponges to various types of physiological or environmental stress conditions. Furthermore, HSP70 protein sequences have been used in phylogenetic analysis of prokaryotes and eukaryotes. In this study, the expression of HSP70 genes in the marine sponge Thenea muricata during long-term cultivation under laboratory conditions was described at the protein and mRNA levels. Though there are many studies about distribution and morphology of T. muricata, few biochemical and molecular data can be found in the literature. HSP70 gene data for several sponge species have been deposited in the NCBI database, however, those for T. muricata are not available. Therefore, HSP70 genes were characterized in this sponge. Several proteins of the HSP70 superfamily which might be induced by stress, were present in T. muricata.

The present study investigates the potential of algal oil (extracted from Nannochloropsis salina), cod liver oil, olive oil and yeast for live prey enrichments in A. percula larviculture. After hatching, larvae were divided into six experimental groups as follows. Larvae fed on non-enriched (control), cod liver oil enriched, olive oil enriched, algal oil enriched, yeast enriched live prey and wild collected mixed plankton. Growth (total length, standard length, body depth, head depth and weight), survival, carotenoid and PUFAs content were observed at higher levels in juveniles fed on wild plankton and algal oil enriched diets. Thyroid hormones (T3, T4 and TSH) levels were also higher in the juveniles fed on wild plankton followed by algal oil enriched diet. Based on the present study, it can be concluded that mixed zooplankton and algal oil enriched rotifers Brachionus plicatilis and Artemia nauplii may be considered suitable live prey for clownfish larviculture.

Although in vivo and in vitro approaches appear to be very different, they are related and complementary techniques and both are essential for the investigation of diverse biological topics. The employment of both techniques was considered particularly appropriate to investigate the role of 17β-oestradiol and testosterone in echinoid reproductive biology. The relationship between sex-steroids and echinoid reproduction has not been clearly determined yet, due to the highly variable and sometimes contrasting results obtained from steroid administration experiments. These might be due to the activation of protective metabolic mechanisms that can prevent the exogenous molecules from exerting their biological functions, as observed in our previous research. To clarify these aspects, in the present study we explored sex-steroid involvement in the reproduction of the sea urchin Paracentrotus lividus, employing both in vivo and in vitro approaches: (1) an experiment involving hormone dietary administration was performed and different reproductive parameters were deeply analysed; (2) ovarian cells were cultured in the presence of the same steroids and morphological and biochemical analyses were carried out. According to our results, sex-steroids appear not to be involved in sea urchin gonad development and gamete maturation, as neither in vivo administration nor in vitro exposure influenced gonad and gamete growth. In addition, in vitro hormonal treatment did not affect sea urchin Major Yolk Protein content. Overall, the present work complements our previous research providing information on sex-steroid involvement in echinoid reproduction and illustrates new methodological approaches that will be useful for future research on invertebrate biology and physiology.

When and where marine eels spawn is poorly known even though species such as those of the family Congridae, Muraenidae and Ophichthidae can be caught in continental shelf habitats. The congrid genus Ariosoma includes small continental shelf eel species whose life histories are not yet known. Mature male and female eels of Ariosoma meeki were observed and captured on 17 August 2009 at the surface at night in the western side of the Kuroshio Current in the East China Sea close to new moon, while they were swimming slowly at the surface and exhibiting apparent reproduction-related behaviour. One male and one sex-unidentified eel (seemingly a male based on body shape) were observed to be chasing one larger female with their heads located near her urogenital pore area. The gonads of the female (540 mm) and the male (410 mm) that were caught by a long-handled dip net were in reproductive condition, because some eggs or seminal fluid were released during handling of the two specimens and high gonad-somatic index (GSI) values of 53 in the female and 20 in the male were recorded. This is one of the few cases in which fully ripe reproductive-condition marine eels have been observed or collected and it provides rare information about the spawning location and timing of this eel species.