Arm Deflation in the Rare Thorny Sea Star, Poraniopsis inflatus (Asteroidea: Poraniidae), A Defensive Response to other Sea Stars?

The Thorny Sea Star, Poraniopsis inflatus, is rare in the Northeastern Pacific. It lacks pedicellariae or other overt defenses for protection against other predatory sea stars. During an earlier study, a P. inflatus confronted by an asteroid-eating sea star was observed to exhibit a possible defensive reaction: "arm deflation." It was 15 years before another P. inflatus specimen could be obtained and that hypothesis confirmed by testing with individuals of 18 other sea-star species. Contact with individuals of four predatory sea-stars, Asterina miniata, Crossaster papposus, Solaster dawsoni, and Pycnopodia helianthoides, elicited the reaction in the P. inflatus. The specimen collapsed ("deflated") an arm closest to the predatory star, possibly by expelling coelomic fluid, exposing more of its embedded thorns (hence its common name) which may discourage other sea stars from attempting to eat it

First record of the Mediterranean asteroid Sclerasterias richardi (Perrier in Milne-Edwards 1882) in the Azores Archipelago (NE Atlantic Ocean)

The first occurrence of the Mediterranean fissiparous asteroid Sclerasterias richardi (Perrier in Milne-Edwards 1882) is reported from the Azores based upon dredged material off the south coast of São Miguel Island at 135 m depth. This record represents a considerable expansion of the species’ geographic range, otherwise reported with certainty only from the Mediterranean Sea. S. richardi is capable of producing long-lived planktotrophic larvae with high dispersal potential to reach remote areas such as the Azores. Alternatively, this species is also capable of reproducing asexually through fission, which could insure the maintenance of viable numbers in a stranded population. The presence of S. richardi in Azorean waters and its rarity in an otherwise thoroughly investigated area does not necessarily imply a recent arrival nor a human-mediated introduction, as the depths in consideration (80-700 m) are also the least studied in the archipelago.info:eu-repo/semantics/publishedVersio

Taxonomic revision of the sea stars of the family Asteriidae Gray, 1840 (Asteroidea: Forcipulatida) from Southwest Atlantic

La revisión de los asteroideos incluidos en la familia Asteriidae (sensu Clark A. y Downey, 1992) es el primer paso para el conocimiento de las especies del Orden Forcipulatida quehabitan el Atlántico Sudoccidental. El propósito principal fue el estudio taxonómico y biogeográfico de las especiespertenecientes a la familia Asteriidae del Atlántico Sudoccidental, se abordaron 2 objetivosespecíficos: 1) Identificar, redescribir e ilustrar los géneros y especies involucrados,mediante herramientas que faciliten y permitan su correcta identificación, utilizandocaracteres morfológicos generales y particulares tales como la morfología y microestructurade espinas y pedicelarios. 2) Determinar la distribución geográfica de las especiesestudiadas. Luego de una exhaustiva revisión bibliográfica y todos los ejemplares accesibles del grupo,se reconocieron 3 especies válidas dentro del género Anasterias: A. antarctica (Lütken, 1897), A. studeri Perrier, 1891 y A. pedicellaris (Koehler, 1923). Se revalidó el nombre Allostichasterhebes (Verrill, 1915) para la especie hasta ahora denominada A. capensis = A. inaequalis. Sereconoció la presencia de la especie Cosmasterias tomidata (Sladen, 1889) para el Atlántico Sudoccidental. Se elaboró una clave dicotómica que permite identificar las especies de Asteriidae. Se verificó y resolvió la distribución geográfica de las especies de Asteriidae. Se analizó la microestructura completa de las piezas calcáreas del esqueleto de losasteroideos estudiados describiendo la variabilidad intraespecífica e interespecífica.The review of the asteroids included in the family Asteriidae (sensu Clark A. and Downey, 1992) is the first step to knowledge the species of the Order Forcipulatida that inhabit inthe Southwest Atlantic. The main purpose was the taxonomic and biogeographic study of species belonging to thefamily Asteriidae in the Southwest Atlantic, addressed two specific objectives: 1) Identify,redescribe and illustrate the genera and species involved, using tools that facilitate andallow a correct identification, harness general and specific morphological characters such asthe morphology and microstructure of spines and pedicellariae. 2) Determine thegeographical distribution of the species studied. After an extensive literature and allavailable ejemplaires of the group review, three valid species in the genus Anasterias wererecognized: A. antarctica (Lütken, 1897), A. studeri Perrier, 1891 and A. pedicellaris (Koehler, 1923). The name Allostichaster hebes (Verrill, 1915) for the species until now named A.capensis = A. inaequalis were revalidated. The presence of the species Cosmasterias tomidata (Sladen, 1889) for the Southwest Atlanticwas acknowledged. A dichotomous key to identify the species of Asteriidae was developed. The geographical distribution of the species of Asteriidae was verified and solved. The complete microstructure of the calcareous parts of the skeleton of the studiedasteroids was analyzed describing intraspecific and interspecific variability.Fil: Romanelli Michel, Mariela Vanina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina

Bright spots in the darkness of cancer: A review of starfishes-derived compounds and their anti-tumor action

The fight against cancer represents a great challenge for researchers and, for this reason, the search for new promising drugs to improve cancer treatments has become inevitable. Oceans, due to their wide diversity of marine species and environmental conditions have proven to be precious sources of potential natural drugs with active properties. As an example, in this context several studies performed on sponges, tunicates, mollusks, and soft corals have brought evidence of the interesting biological activities of the molecules derived from these species. Also, echinoderms constitute an important phylum, whose members produce a huge number of compounds with diverse biological activities. In particular, this review is the first attempt to summarize the knowledge about starfishes and their secondary metabolites that exhibited a significant anticancer effect against different human tumor cell lines. For each species of starfish, the extracted molecules, their effects, and mechanisms of action are described

Regeneration rate after fission in the fissiparous sea star Allostichaster capensis (Asteroidea)

Many studies have focused on the regeneration rate of arms in Asteroidea but no studies have focused on the regeneration rate after fission. Allostichaster capensis is a fissiparous sea star with a wide range of dis- tribution. In Golfo Nuevo (42°46’49’’ S - 64°59’ 26’’ W) sea stars undergo fission every spring and summer and regenerate the rest of the year. To analyze the regeneration rate, we conducted an experiment with sea stars collected just before fission. After sea stars underwent fission, the length of the three non-regenerating and the three regenerating arms were measured weekly. The arm length (regenerating and non-regenerating) was used in non-Linear Mixed Effect models in order to account for within-individual correlation in different models. The regenerating arms regenerate according to a Quadratic model, while the non-regenerating arms regenerate according to a linear model. In the regenerating arms, the regeneration rate was estimated to be 0.1 mm.week -1 and in the non-regenerating arms, the growth rate was 0.004 mm.week -1 . Sea stars regenerate ca. 20 % of the arm in one month, and it takes about 5 months to be completely regenerated. At the beginning, the regeneration rate is fast generating the growth of the arms, once the pyloric caeca and gonads are present inside the arms the regeneration rate slows down probably due to allocation to gametes and pyloric caeca and arms. The factors that regulate the regeneration rate are unknown. However, food availability and energy storage seem to play an important role. Rev. Biol. Trop. 63 (Suppl. 2): 321-328. Epub 2015 June 01.Fil: Rubilar Panasiuk, Cynthia Tamara. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Centro Para El Estudio de Sistemas Marinos; ArgentinaFil: Meretta, Pablo Ezequiel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencia Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; ArgentinaFil: Cledón, Maximiliano. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencia Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; Argentin

Global Diversity and Phylogeny of the Asteroidea (Echinodermata)

Members of the Asteroidea (phylum Echinodermata), popularly known as starfish or sea stars, are ecologically important and diverse members of marine ecosystems in all of the world's oceans. We present a comprehensive overview of diversity and phylogeny as they have figured into the evolution of the Asteroidea from Paleozoic to the living fauna. Living post-Paleozoic asteroids, the Neoasteroidea, are morphologically separate from those in the Paleozoic. Early Paleozoic asteroid faunas were diverse and displayed morphology that foreshadowed later living taxa. Preservation presents significant difficulties, but fossil occurrence and current accounts suggests a diverse Paleozoic fauna, which underwent extinction around the Permian-Triassic interval was followed by re-diversification of at least one surviving lineage. Ongoing phylogenetic classification debates include the status of the Paxillosida and the Concentricycloidea. Fossil and molecular evidence has been and continues to be part of the ongoing evolution of asteroid phylogenetic research. The modern lineages of asteroids include the Valvatacea, the Forcipulatacea, the Spinlosida, and the Velatida. We present an overview of diversity in these taxa, as well as brief notes on broader significance, ecology, and functional morphology of each. Although much asteroid taxonomy is stable, many new taxa remain to be discovered with many new species currently awaiting description. The Goniasteridae is currently one of the most diverse families within the Asteroidea. New data from molecular phylogenetics and the advent of global biodiversity databases, such as the World Asteroidea Database (http://www.marinespecies.org/Asteroidea/) present important new springboards for understanding the global biodiversity and evolution of asteroids

PRELIMINARY CHECKLIST OF THE UNDERSEA FAUNA OF THE ROSS SEA ANTARCTIC CONTINENTAL SHELF BASED ON YO-YO CAMERA SURVEYS

As part of an expedition aboard the Nathaniel B. Palmer RVIB, hundreds of still images were captured of the Ross Sea continental shelf seafloor. Using a crowd-sourced group of experts, we identified the fauna captured in these images, identifying over 1000 organisms to 15 major taxonomic groups (viz., anemones, bivalves, brittle stars, cephalopods, corals, crinoids, crustaceans, fishes, holothurians, isopods, pycnogonids, sea urchins, sea stars, sponges, tunicates). On the basis of the organisms we could identify to genus or species, we compiled a checklist of the fauna from this poorly-known area. The images from this yo-yo camera survey show a diverse community of life that was largely unknown for this sector and may reveal expanded ranges for some species and potentially new ecological information.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/168230/1/UMMP_MP_209-2.pdfMain ArticleSEL

Abstracts of Contributed Papers Presented at the 1998 North American Echinoderms Meeting August 16-19, 1998, Wallops Island Marine Science Center, Wallops Island, Virginia

Following the tradition started at the Dauphin Island Sea Lab (1989), and continued at the Harbor Branch Oceanographic Institution (1992), the third North American Echinoderms Meeting was sponsored by the Marine Science Consortium and held at the Wallops Island Marine Science Center in August of 1998. In keeping with the practices of prior meetings, this meeting provided a forum for colleagues from throughout North America to share current work, and fostered communication between researchers whose work is based upon some aspect of the biology of Echinodermata. Presentations covered a range of topics, from evolutionary relationships to ecological processes and from physiological mechanisms to aquacultural applications, illustrating the breadth of activities of researchers investigating the Echinodermata. Following are abstracts resulting from oral or poster presentations contributed to the 1998 North American Echinoderms Meeting, and a special, invited retrospective on meetings on Echinodermata in North America