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We developed a rapid, practical and non-toxic salting-out method for the extraction of DNA from marine organisms, and tested it on two representative species of Porifera and Cnidaria, both living in association with symbiotic zooxanthellae. We tested the efficiency of the protocol by comparing the output of the method for fresh tissue, frozen tissue and tissue stored in ethanol. It proved to be effective for extracting DNA in the case of the methods of preservation considered here, and for obtaining quantities of DNA comparable to those obtained via the traditional approach. The DNA from both species was of good quality. The DNA obtained was amplified by PCR using specific primers for the large ribosomal subunit, allowing the identification of the presence of both the host and symbiont genomes.

The life cycle of Hydrozoans typically comprises two phases: the polyp, either solitary or colonial, with generally a benthic habitat, and the medusa which lives in the plankton. In its typical metagenetic cycle, the medusa is budded from the polyp, which is the product of sexual reproduction of medusae. However, several alternative reproduction patterns have also been described. In particular some species are able to perform a regressive transformation of the medusae that transform themselves into polyps bypassing sexual reproduction. In a species with alternative morphs switched by the environment, the more labile is the correlation between environmental factors acting on the genetic switch and the factors to which the resulting form is adapted, the more hazardous will be the development of either body form. However, we can explain the evolutionary advantage offered by reversion between morphs of these plastic species living in shallow water unpredictable environments: should produced medusae be released in the "wrong" environment, they would still have a chance of survival under another form.

Stylasterids belong to one of the few calcifying hydroid families that are commonly found in shallow tropical coral reefs. Although these corals are accurately described from a taxonomic point of view, information about their ecology is scarce. Distichopora violacea is one of the most common stylasterids of the Indo-Pacific region; however, no information is yet available on its distribution and abundance. To fill this gap data we gathered data during three scientific expeditions on four Maldivian atolls. In each atoll investigations were carried out at three depths, both in the ocean and in the lagoon reef, to examine differences in colony density and distribution. Distichopora violacea was observed in all the studied atolls; however, its distribution and density were not homogeneous among them. This species was more abundant in the ocean reefs than in the lagoon ones, suggesting a strong influence of water movement. Moreover, we found a high variability in colony density in the eastern ocean reefs that was tentatively attributed to a different topography of the reef: colonies were more abundant on the gentle slopes of Malè atolls than on the steep reefs of Felidhoo. Oceanographic features, mainly due to the seasonal monsoons, are likely to interact with the biological requirements of the species in determining the observed asymmetrical geographical distribution. The present investigation provides new insights on the stylasterid D. violacea and, for the first time, quantitative data on its distribution and density that can be useful for conservation and management of this CITES regulated species. [ABSTRACT FROM AUTHOR]

Cnidarians are known for their simple body plan and their complex life cycles, involving high regenerative and asexual-reproduction potential. In particular, several asexual reproductive strategies are known for anthozoans, including fragmentation, carried out by tentacles, by groups of polyps or by portions of colonies. Here, we report the first observation of an extensive event of fragmentation in the Mediterranean black coral species Antipathella subpinnata (Antipatharia: Myriopathidae) in rearing conditions. Once detached, fragments lose their polarity and new anchorages are rapidly created with polyps and cnidocysts participating in the adhesion phases. Multiple attachments are frequently observed, with new skeletal plates produced through the expansion of spines. Dendritic spines gradually arise on these new plates. Fragments start to generate numerous new branchlets orientating upward and with a fixed arrangement. In 7 months of monitoring, fragments revealed fast growth rates, up to 1.85 and 1.58 cm month−1, for the whole fragments and new branchlets, respectively. Attachment of black coral fragments has never been recorded in the field; nevertheless, frequent adhesions observed in aquaria suggest that fragmentation could be a successful reproductive strategy in these anthozoans. [ABSTRACT FROM AUTHOR]

The new species, Pseudocirrhipathes mapia, is herein described from specimens coming from the coral reefs of the Bunaken Marine Park (North Sulawesi, Indonesia). The species is characterized by an unbranched thin corallum up to 1 m high (maximum basal thickness 4 mm), with large polyps arranged irregularly on one side of the stem, and by tentacles that are not completely contractile. The skeleton shows an array of spine morphologies along the stem, although most are typically verticillated in the apical section and highly tuberculated in the central portion. The study of its cnidome revealed the presence of an extremely long basitrich isorhiza. The morphological analysis has been coupled with a molecular study of the rDNA ITS sequences confirming the existence of the new genus Pseudocirrhipathes and its inclusion, together with the genus Allopathes, in a separate clade related to the Antipathidae. [ABSTRACT FROM AUTHOR]

Five species of Macrorhynchia from the Bunaken National Marine Park (North Sulawesi, Indonesia) are described. Three species, M. philippina, M. spectabilis and M. phoenicea were already known for the Indo-Pacific area, M. asymmetrica and M. fulva are described as new species. Macrorhynchia asymmetrica n. sp. is easily distinguished from the other species of the genus due to the hypertrophic lateral nematotheca that is bent downwards. Macrorhynchia fulva n. sp. is distinguishable from its congeners especially through the lateral nematothecae pointing in opposite directions, the large marginal tooth, and the presence of the well-marked adcauline teeth. The shape and the colour of living colonies are described, thereby allowing the recognition of the species directly in situ. Generally, the observed species live on the deeper portions of the reef, but M. spectabilis occurs at more shallow depths. Almost all the recorded species have an annual cycle characterised by higher abundances during the wet season while they are absent or rare during the dry period. Only M. asymmetrica has the opposite pattern, being more abundant during the dry months. [ABSTRACT FROM AUTHOR]

A wealth of data are available on the seasonal variation of plankton communities, but few studies take into consideration the circannual cycles of benthic organisms. In fact, the macrobenthos is generally considered as composed by slow-growing organisms showing variations mainly in relation to substrate competition. On the contrary, hydroids are an important group of macrobenthos that, in temperate but also in tropical waters, undergo sharp seasonal cycles. For example, on the Portofino Promontory (Ligurian Sea), about half of the recorded species thrive in winter and 30% in the summer, the rest being constant in presence. Here, we revise the available data about the environmental factors switching the passage from quiescent to active phases. The available data suggest that a mosaic of physical factors, biotic interactions, and internal clues triggers the hydroid cyclic behaviour. [ABSTRACT FROM AUTHOR]

Eudendrium glomeratum Picard, in the Ligurian Sea, is one of the major components of hard-bottom sessile zoobenthos in the cold season. It settles mainly between 10 and 40 m depth, forming a seasonal facies. The presence of E. glomeratum has been evaluated by measuring in situ the height of the colonies present within a standard surface of 1 m. Observations were carried out every other week for a whole year. The height of the colonies was correlated with their biomass (wet weight) and trophic functionality (number of polyps). The quantitative evaluation of the population shows that the situation is stable, with almost identical values at the extremes of the observed yearly time series. The species is present from October to April-May, and it is absent in the summer. The formation and disappearance of the E. glomeratum population are sudden. The colonies are sexually mature from their appearance in October to December-January. Different categories of colonies are recognizable; and are essentially referable to two groups: (1) colonies deriving from regeneration of colonies present in the previous year (45%); (2) colonies deriving from planula settlement (43%). A third group (12%) is of uncertain origin and may belong to either of the abovementioned categories. Mortality is 60% in the first group, and 82% in the second one. By 'dead colonies' is meant those which do not reappear after a yearly cycle. [ABSTRACT FROM AUTHOR]

The article offers information on the study conducted on the pink and white species of Stylasteridae found at the coral reefs of the Bunaken Marine Park in North Sulawesi, Indonesia. Collected specimens show that the colony of Stylasteridae exist in two colours, the white and pink, which lived in groups inside caves and crevices. They observed that the pink corals are distributed on the sides exposed to light and its color is due to the decalcification of its branches with 4% hydrochloric acid.

The growth rate of two species of whip black corals belonging to the genera Cirrhipathes and Stichopathes has been evaluated in different experiments conducted in the Marine Park of Bunaken (Indonesia) for over one year. Unbranched, unpinnulated black corals result among the fastest growing colonial organisms, with maximal growth rates of 13.25 cm month−1 for Cirrhipathes cfr anguina and 1.3 cm month−1 for Stichopathes cfr maldivensis. Several observations made both on transplants and on natural colonies add new information on the growth strategy of black corals. The easy handling, the high rate of survivorship and the fast growth of transplants indicate that black corals can be successfully employed in the recovery projects of harvested reefs. [ABSTRACT FROM PUBLISHER]