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- First record of the genus Periclimenaeus borradaile, 1815 (decapoda : palaemoniidae : pontoniinae) in the northeastern Atlantic, with the description of a new species, Periclimenaeus auraePublication . Dos Santos, Antonina; Calado, Ricardo; Araujo, RicardoA new species of Periclimenaeus is described from Madeira Island, in the northeastern Atlantic Ocean. It is closest to P. pearsei Holthuis, 1951 from the western Atlantic, but it can be distinguished by the shape of rostrum, the size of exopod in relation to endopod in third maxilliped, the relation between the carpus and the chela of pereiopod 1, the relative size of second pereiopod minor chel a, and the number of setae on appendix masculina. This is the first record of the genus Periclimenaeus in the eastern Atlantic.
- Complete larval development of the hermit crabs Clibanarius aequabilis and Clibanarius erythropus (Decapoda : Anomura : Diogenidae), under laboratory conditions, with a revision of the larval features of genus ClibanariusPublication . Bartilotti, Catia; Calado, Ricardo; dos Santos, AntoninaThe complete larval development (four zoeae and one megalopa) of Clibanarius aequabilis and C. erythropus, reared under laboratory conditions, is described and illustrated. The larval stages of the two northeastern Atlantic Clibanarius species cannot be easily differentiated. Their morphological characters are compared with those of other known Clibanarius larvae. The genus Clibanarius is very homogeneous with respect to larval characters. All Clibanarius zoeae display a broad and blunt rostrum, smooth abdominal segments and an antennal scale without a terminal spine. Beyond the second zoeal stage, the fourth telson process is present as a fused spine, and the uropods are biramous. In the fourth larval stage all species display a mandibular palp. The Clibanarius megalopa presents weakly developed or no ocular scales, symmetrical chelipeds, apically curved corneous dactylus in the second and third pereiopods, and 5-11 setae on the posterior margin of the telson. Apart from the number of zoeal stages, Clibanarius species may be separated, beyond the second zoeal stage, by the telson formula and the morphology of the fourth telson process.
- Bopyrid isopods do not castrate the simultaneously hermaphroditic shrimp Lysmata amboinensis (Decapoda : Hippolytidae)Publication . Calado, Ricardo; Vitorino, Antonio; Dinis, Maria TeresaThis study evaluates possible parasitic castration induced by a bopyrid isopod of the genus Parabopyrella, which parasitizes the branchial chamber of the simultaneously hermaphroditic shrimp Lysmata amboinensis. Parasitized shrimp (PS) carried embryos and produced significantly fewer larvae (mean +/- SD: 363 +/- 102; p = 0.002) than formerly parasitized shrimp (FPS) (1297 +/- 143) and unparasitized shrimp (US) paired with other US (1409 +/- 102), with PS (1362 +/- 234) or with FPS (1384 +/- 157). Starvation trials revealed no significant differences in the quality of larvae produced by PS, FPS and US paired with other US, PS and FPS. Host embryo production is only quantitatively, not qualitatively, affected, probably due to nutritional drain and/or endocrine disruption caused by the parasite. The host male sexual system remains fully functional and 'reproductive death' does not occur. The feminization of pleopods that prevents parasitized males of gonochoric species from successfully copulating seems to have no effect on L. seticaudata: pleopods are always feminized during their transition from male to simultaneous hermaphrodite phase, with adults being able to successfully fertilize broods. Parabopyrella sp. significantly affects the female sexual system of its host, but does not cause castration, as recorded for L. seticaudata parasitized by the bopyrid isopod Eophryxus lysmatae (an abdominal parasite).
- Facultative secondary lecithotrophy in the megalopa of the shrimp Lysmata seticaudata (Risso, 1816) (Decapoda : Hippolytidae) under laboratory conditionsPublication . Calado, Ricardo; Dionisio, Gisela; Nunes, Cristovao; Dinis, Maria TeresaCertain decapod crustaceans can catabolize internal reserves to undergo partial or full larval development. This feature is termed secondary lecithotrophy, if energy used results from plankton derived organic matter accumulated Ig earlier larval stages. The present work reports the ability of Lysmata seticaudata megalopa to moll to the first juvenile stage in the absence of food. Unlike previous records of secondary lecithotrophy displayed by nonfeeding last larval stages of hermit crabs and spiny lobsters, the megalopa of L. seticaudata retains its feeding capacity. This is the first time such a feature has been reported in decapods, and the term facultative secondary lecithotrophy is proposed. The build up of energy reserves continues during the last zoeal stage of L. seticaudata, with starved zoea IX failing to molt to megalopa. Energy reserves that enable starved megalopa to molt to juvenile seem to be partially depleted, with starved juveniles produced either from, starved or fed megalopae being unable to molt to the next juvenile stage. The longer resistance of starved juveniles produced from fed megalopae (nine days), compared to that of starved juveniles produced from starved megalopae (five days), indicates that some energy reserves may pass to juvenile, not being totally depleted at metamorphosis.
- Decapod crustaceans associated with the snakelock anemone Anemonia sulcata. Living there or just passing by?Publication . Calado, Ricardo; Dionisio, Gisela; Dinis, Maria TeresaThe present work identifies the decapod crustaceans that associate with Anemonia sulcata on the southwestern Atlantic coast of Portugal and characterises their host use pattern. It determines whether the anemone is monopolised by any species, resulting in the exclusion of conspecifics or other decapods and, under laboratory conditions, it evaluates the degree of association between each species and A. sulcata. From all sampled anemones, 79% harboured at least I decapod crustacean, with the majority displaying either one or two specimens (32 and 24%, respectively). The most abundant species were the shrimp Periclimenes sagittifer and the crab Inochus pholangium (representing 36 and 3 1 % of collected specimens, respectively), which displayed lasting associations and were commonly recorded among the tentacles of the host. The species Eualus occultus, E. complex cranchii, Clibanarius erythropus, Maja brachydactyla, Pilummus hirtellus and Polybius (Necora) puber displayed short-term associations, were mainly present on the substratum near the base, and avoided the tentacles of A. sulcata. Periclimenes sagittifr and I. phalangium were only recorded alone or in heterosexual pairs, appearing to efficiently defend their host against conspecifics. The majority of recorded species only seem to temporarily associate with A. sulcata, in order to seek protection from predators when other shelters are unavailable.
- Marine ornamental species from European waters: a valuable overlooked resource or a future threat for the conservation of marine ecosystems?Publication . Calado, RicardoThe worldwide growth of the marine aquarium market has contributed to the degradation of coral reef ecosystems. Enforcing the legislation on importing ornamental species has led some European traders to concentrate on local species. Portugal is used as a case study of marine ornamental fish and invertebrate collection in European waters. One hundred and seventy two species occurring in Portuguese waters (mainland, the Azores and Madeira archipelagos) were considered as potential targets for the marine aquarium industry, some of which are already traded on a regular basis (e.g. Clibanarius erythropus, Lysmata seticaudata, Cerithium vulgatum, Hinia reticulata and Ophioderma longicauda). To ensure appropriate management and conservation of these resources, the following options have been evaluated: banning the harvest and trade of all marine ornamental species from European waters; creating sanctuaries and "no take zones"; issuing collection permits; creating certified wholesalers; implementing the use of suitable gear and collecting methods; setting minimum and maximum size limits, establishing species-based quotas; protecting rare, or "key stone" species and organisms with poor survivability in captivity; establishing closed seasons; culturing ornamental organisms; and creating an "eco-fee" to support research and management. Establishing this sustainable alternative fishery may help minimise the economical and social impacts caused by the crash of important food fisheries in Portugal and other European and West African countries.
- Improvements to the "sket bottle": a simple manual device for sampling small crustaceans from marine caves and other cryptic habitatsPublication . Chevaldonne, Pierre; Sket, Boris; Marschal, Christian; Lejeusne, Christophe; Calado, RicardoDark littoral submarine caves can act as enclaves of the deep aphotic zone in shallow coastal areas, and their survey has revealed the existence of a very particular fauna of specialized and poorly known organisms among which crustaceans are particularly well represented. In these particular habitats, the use of conventional sampling techniques, such as hand nets, is often not recommended since they disturb bottom sediments causing hazardous situations to scientific divers. The use of baited traps, while technically possible, is not. always practical is such remote habitats. The present work describes a simple and inexpensive manual device that can be operated by divers ill submarine caves and other cryptic habitats to recurrently catch small motile organisms such as mysid crustaceans, caridean shrimps, or even gobiid fishes. This small suction bottle derived and improved from the original "Sket bottle" design considerably reduces the risks of disturbing the cave's bottom sediment and can be easily operated using a single hand. The described sampling device can also be easily used outside caves, in a variety of particular habitats, e.g., rubble filled bottoms, branching coral reefs, cracks, and small holes on rocky surfaces, in which small motile organisms usually escape from traditional sampling gears, e.g., fishnets and traps, or simply go unnoticed by researchers during sampling.