Polychaete zonation and its relation to algal distribution down a vertical cliff in the western Mediterranean (Italy): a structural analysis

none1noThe zonation of polychaetes down a vertical cliff (0-5 m in depth) at Cape Romito, Leghorn, Italy, was investigated. The structural organization of the community changed with depth. A community typical of photophilic environments was found in the superficial zone (0-2 m), while in the deeper zone (3-5 m), a more diversified community characterized by species typical of sciaphilic environments was present. At the surface (0 m) the community was very poor in species and individuals and thus probably corresponds to the midlittoral fringe. In fact, some species typical of the midlittoral zone were found. This distribution pattern was constant for samples taken in February and August 1985. The distribution of polychaetes was closely related to that found for macroalgae. It is hypothesized that algae condition the substratum and that this is the main factor responsible for the zonation of polychaetes. © 1988.openGiangrande A.Giangrande, A

Seasonal and bathymetric effects on macrofouling invertebrates’ primary succession in a mediterraenan non-indigenous species hotspot area

The present study investigates macrofouling development in the Mar Grande of Taranto (Central Mediterranean Sea), a wide confined area that has attracted considerable attention in recent years due to the establishment of numerous non-indigenous species (NIS). Different starting times of a yearly primary succession on artificial substrates were tracked so as to investigate the matching of the development pattern with contingency and/or convergence models, identifying NIS’s structural role in the community endpoint. Our results show that during the experiment all assemblages tended to converge towards multiple contingent communities according to starting times and depths. The differences are due to propagule availability which influence further species interactions. Thus the endpoint patterns are defined by a contingent community development determined by the seasonal species pool, their phenologies, pre- and post-settlement events, and species interactions. The most important structuring species was Mytilus galloprovincialis, which was present in almost all the endpoint assemblages, in particular when it recruits at early stages of the community development. Another abundant species at the endpoint was the alien Branchiomma boholense; which was a persistent structural component contributing to an alternative state in which Mytilus galloprovincialis loses its structural importance and where B. boholense becomes dominant, leading to an increase in fouling biodiversity of the endpoint assemblage

The genus Novafabricia Fitzhugh, 1990 (Polychaeta: Sabellidae: Fabriciinae) en la costa italiana (Mar Mediterráneo) con la descripción de N. posidoniae n. sp.

The new species, Novafabricia posidoniae is described for the Mediterranean Sea, and Novafabricia sp. cf. N. infratorquata (Fitzhugh, 1983) is reported for the eastern Mediterranean basin. The genus Novafabricia Fitzhugh, 1990, represented up to now in the Mediterranean only by N. infratorquata, is recorded for the first time along the Italian coast. Novafabricia posidoniae belongs to the group of Novafabricia species with pseudospatulate chaetae present in thoracic chaetigers 3-5. The addition of this new species raises the number of Novafabricia species to 10.  El genero Novafabricia Fitzhugh, 1990, representado en el Mediterráneo únicamente por N. infratorquata, se cita por primera vez para las costas italianas. Se describe Novafabricia posidoniae como especie nueva en base a ejemplares del Mediterráneo y se cita Novafabricia sp. cf. N. infratorquata (Fitzhugh, 1983) para el Mediterráneo oriental. N. posidoniae pertenece al grupo de especies del género con sedas pseudoespatuladas en los setígeros 3-5. La presente descripción incrementa a 10 el número de especies conocidas de Novafabricia.

Seasonal and bathymetric effects on macrofouling invertebrates' primary succession in a mediterraenan non-indigenous species hotspot area

The present study investigates macrofouling development in the Mar Grande of Taranto (Central Mediterranean Sea), a wide confined area that has attracted considerable attention in recent years due to the establishment of numerous non-indigenous species (NIS). Different starting times of a yearly primary succession on artificial substrates were tracked so as to investigate the matching of the development pattern with contingency and/or convergence models, identifying NIS's structural role in the community endpoint. Our results show that during the experiment all assemblages tended to converge towards multiple contingent communities according to starting times and depths. The differences are due to propagule availability which influence further species interactions. Thus the endpoint patterns are defined by a contingent community development determined by the seasonal species pool, their phenologies, pre- and post-settlement events, and species interactions. The most important structuring species was Mytilus galloprovincialis, which was present in almost all the endpoint assemblages, in particular when it recruits at early stages of the community development. Another abundant species at the endpoint was the alien Branchiomma boholense; which was a persistent structural component contributing to an alternative state in which Mytilus galloprovincialis loses its structural importance and where B. boholense becomes dominant, leading to an increase in fouling biodiversity of the endpoint assemblage

The genus Euchone (Polychaeta, Sabellidae) in the Mediterranean Sea, addition of two new species and discussion on some closely related taxa

Mediterranean sabellid material preserved in the private collection of the Zoological Laboratory of Lecce University has been examined in order to revise all the specimens belonging to Euchone and related genera (Annelida: Polychaeta: Sabellinae). The description of two new species, E. pararosea n. sp. and E. pseudolimnicola n. sp., is given together with the re-description of E. rosea. The record of E. southernii and E. capensis previously reported for the Mediterranean Sea, as well as some taxa showing intermediate features among Euchone, Chone, and Amphicorina are discussed, focusing on the thoracic uncini shape. Cladistic analysis was also performed in order to clarify the systematic position of the newly described tax

The genus Echinofabricia (Annelida: Fabriciidae) in the Mediterranean Sea with the description of E. rousei sp. nov.

The new species Echinofabricia rousei is described for the Mediterranean Sea based on specimens collected along the Sardinia Coast (Porto Conte). The genus Echinofabricia is reported for the first time in the Mediterranean area. At present three species are described within the genus: E. goodhartzorum, described from the Caribbean, E. dubia, described from the East Pacific (Hawaii) and E. alata from Australia

Diversity and Distribution of Sabellida (Annelida) under Protection Regimes

Sabellida are widespread, diverse and abundant in marine benthic habitats. Their distribution patterns on hard-bottom substrates are poorly studied so far. Little is known about the factors influencing their distribution, including the protection regimes that are known to affect assemblage diversity. We analyzed hard-bottom Sabellida at 1.5 and 5 m depths at the Torre Guaceto Marine Protected Area (MPA) (SE Italy) to describe diversity and distribution patterns, and to identify potential factors influencing their distribution. The Sabellida diversity varied significantly among stations and was higher at 5 m depth. No relation with the protection regime was found. Among environmental variables, only sedimentation appeared related, suggesting that local trophic features might have influenced the observed pattern. Among habitat formers, only the macroalga Halimeda tuna significantly explained part of the observed variation, probably due to its role as a basibiont for some Sabellida taxa. Other predictor variables of Sabellida distribution were the abundances of some invertebrate taxa, especially Syllidae and some filter feeders such as Sabellariida and Cirripedia, probably due to shared ecological requirements, rather than a direct effect on Sabellida distribution. The relation with the Syllidae remains obscure so far, albeit some kind of interaction (including predator/prey interactions) between these two taxa cannot be excluded. Sabellida should be taken into account when analyzing patterns of biodiversity of hard-bottom environments

Sabellidae (Annelida) from the Faro coastal lake (Messina, Ionian Sea), with the first record of the invasive species Branchiomma bairdi along the Italian coast

In the present paper, morphological and ecological observations on 4 sabellid taxa, Branchiomma bairdi, B. luctuosum,Megalomma lanigera and Myxicola sp., collected from the coastal lake of Faro (Messina, Ionian Sea) (26-36 psu), are reported. Megalomma lanigera, Myxicola sp. and B. luctuosum were collected from the soft bottom in shallow water and B. bairdi from the hard bottom of an internal channel. The presence of the latter is remarkable, as there is no previous record of this species along the Italian coast, and it confirms the lake of Faro as a very favourable environment for the introduction of alien species, which has occurred frequently as a result of aquaculture. High intraspecific variation was observed for M. lanigera, whilst more extensive analysis is required to ascertain the taxonomic status of the Myxicola specimens, including a review of all Mediterranean data currently attributed to M. infundibulum