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Submerged artificial surface imitates newly available habitat for settlement of marine fauna. It also enables study of the timing of benthic larval settlement. Such knowledge is important if the model of possible recovery after disturbance in protected areas is to be assessed. During this study recruitment of sessile benthic invertebrate fauna at spatial and temporal scales was investigated using artificial panels submerged in the Skomer Marine Nature Reserve (Wales, UK). Panels were exchanged monthly between May 2009 and September 2011 (with the exclusion of winter time). Recruitment was highly variable with regard to time and distribution; abundance and number of recruiting species varied significantly between sites (about 2 km apart from each other), depths (6 and 12 m), position on panels (top or underside) and years without any obvious trends. The highest number of individuals and highest values of species richness were at Bernies Rocks, at the greater depth and on the underside surface of panels. Bryozoans were the dominant taxon on panels in each studied year and month. Most macrofaunal species noted on panels exhibit a colonial life strategy with short-lived, non-feeding larval stage. Although many species settle all year round, levels of settlement usually peak in summer months, showing a seasonal recruitment pattern (Bugula fulva, Spirobranchus triqueter, Chorizopora brongniarti and Escharoides coccinea). Some species had a pronounced settlement peak in spring (e.g. Electra pilosa and Balanus crenatus).
Cephalopods (Mollusca: Cephalopoda) play an important role as keystone invertebrates in various marine ecosystems, as well as being a valuable fisheries resource. At the World Malacological Congress, held 21–28 July 2013 in Ponta Delgada, Azores, Portugal, a number of cephalopod experts convened to honour the contribution of the late Malcolm R. Clarke, FRS (1930–2013) to cephalopod research. Endorsed by the Cephalopod International Advisory Council (CIAC), the meeting discussed some of the major challenges that cephalopod research will face in the future. These challenges were identified as follows: (1) to find new ways to ascertain the trophic role and food web links of cephalopods using hard tissues, stable isotopes and novel concepts in theoretical ecology; (2) to explore new approaches to the study of cephalopod morphology; (3) to further develop cephalopod aquaculture research; (4) to find new ways to ascertain cephalopod adaptation and response to environmental change; (5) to strengthen cephalopod genetics research; and (6) to develop new approaches for cephalopod fisheries and conservation. The present paper presents brief reviews on these topics, followed by a discussion of the general challenges that cephalopod research is bound to face in the near future. By contributing to initiatives both within CIAC and independent of CIAC, the principle aim of the paper is to stimulate future cephalopod research.
Olindias spp. medusae are found worldwide in sublittoral tropical and sub-tropical coastal regions; their occurrence near shore can result in human envenomation events. While behaviour of medusae and human contact with medusae has been documented for the genus, the hydroid (polyp) phase of the Olindias life cycle has eluded investigators for over a century. Given the recent debate among public media and scientific communities that jellyfish blooms are increasing worldwide, there is a growing urgency to understand how and why jellyfish populations bloom. In order to understand jellyfish population dynamics, the asexual benthic phase must be studied to determine when, where, and how juvenile medusae are produced. In this study, husbandry management strategies, including the creation of artificial habitat for Olindias formosus medusae in aquaria were developed to encourage spawning and larval settlement. The resultant hydroid colony of Olindias formosus was discovered in November of 2012, utilizing the natural fluorescence of the medusa as a detection method. A description of the hydroid and early medusa stage is presented. These techniques provide a basis for locating in situ the benthic hydroid phases within this genus and other fluorescent medusae, the discovery of which may lead to a better understanding of the causative factors for jellyfish blooms.
A new Scyllaeidae of the genus Notobryon is described from Guadeloupe, in the Lesser Antilles. Notobryon caribbaeus sp. nov. is characterized by having the anterior pair of body lobes remarkably bigger than the posterior pair, a stomach with eight triangular plates, a black and very wide ampulla, a lemon-shaped bursa copulatrix and a complex and well-differentiated sponge-like prostate. The first Caribbean records of Notobryon were provisionally assigned to the Australian species Notobryon cf. wardi and later transferred to Notobryon panamica. However, the structure of the male genital system is one of the main morphological characters to discriminate species in the genus and the presence of a prostate in N. caribbaeus sp. nov. distinguishes it from N. panamica, which remains confined to the eastern Pacific. Of the remaining four species in the world, only Notobryon bijecurum shares this character, but its external anatomy is different: it lacks a bursa copulatrix and the deferent duct is much shorter. Notobryon caribbaeus sp. nov. was captured in the context of an intensive expedition (‘Karubenthos’) organized by the Muséum National d'Histoire Naturelle, Paris and its description raises the total inventory of sea slugs in Guadeloupe to 150.
Phelloderma oxychaetoides sp. nov. is a remarkable new species from the deep Weddell Sea, bearing abundant oxychaetes (onychaete-like microxeas), morphologically distinct from the onychaetes of Tedania spp. collected in the same area. We give a redescription of the holotype of P. radiatum Ridley & Dendy, 1886, the type species of Phelloderma. We recognize three and a possible fourth species in Phelloderma: P. flava (Lévi, 1993); P. oxychaetoides sp. nov.; P. polypoides Whitelegge, 1906; and P. radiatum Ridley & Dendy, 1886. An identification key for the species of Phelloderma is proposed. A discussion on the affinities of Phelloderma to both Mycalina and Myxillina is offered, and the current preference for the latter is further supported by the marked similarity between the oxychaetes of Phelloderma oxychaetoides sp. nov. and those of Chaetodoryx spp. (Coelosphaeridae, Myxillina).
The diet and the trophic level of the Argentine hake Merluccius hubbsi was investigated in the south-west Atlantic Ocean. Stomachs from 3405 specimens, ranging from 10 to 94 cm total length, collected on three research cruises carried out during winter 2011 and summer 2012, were examined at the laboratory. Dietary shifts related to sex, maturity stage, size, age, season, region and hour were examined using generalized linear models. The Argentine hake M. hubbsi fed mainly on zooplankton crustaceans (Themisto gaudichaudii, Euphausia lucens and Munida spp.), followed by fish and cephalopods. During summer, cephalopods (mainly Illex argentinus) were the main prey of M. hubbsi, indicating spatio-temporal changes in the diet. This work also revealed ontogenetic dietary changes associated with size, from zooplankton crustaceans during early life stages (E. lucens, T. gaudichaudii and Munida spp.) to fish and cephalopods. The trophic level of M. hubbsi ranged from 3.43 to 4.51 according to season and region. Cannibalism increased with predator length and contributed a maximum of 8.14% to the diet of M. hubbsi during winter on the inner Patagonian continental shelf.
The spatial and temporal variations of planktonic cnidarians were studied across the inner continental shelf (≤40 m) off the State of Paraná in southern Brazil. Monthly zooplankton samples were taken between November 1997 and March 1999 at five stations. The holoplanktonic Liriope tetraphylla and Muggiaea kochi dominated during the entire period, comprising >80% of the specimens. The coast–ocean gradient became evident due to a near-coastal (≤20 m) assemblage formed by L. tetraphylla, Solmaris corona and meroplanktonic medusae, and a distinct outer (25–40 m) assemblage formed by the medusae Corymorpha gracilis and Aglaura hemistoma and siphonophores. The estuarine runoff during warm rainy periods lowered the salinity (~30) at the inner stations (1, 2 and 3), providing appropriate conditions for the estuarine/coastal species. Wind-driven onshore advection of outer-shelf species to the inner isobaths occurred from late autumn to winter, when the rainfall decreased and salinity increased (>35). Population peaks occurred in both summer and winter at the inner stations. For most species, the seasonal patterns were inconsistent with other studies conducted in the Southern Brazilian Bight, suggesting irregular and unpredictable seasonal distributions of abundance. Whereas in high-latitude ecosystems the dynamics of cnidarian populations follows the seasonal productivity cycle, here, complex hydrographic processes seem to be more important in determining the structure and seasonal dynamics of this community.