Francesco Denitto

Nonindigenous species along the Apulian coast, Italy

Thirty-eight nonindigenous marine species (NIS) (macroalgae, sponges, hydrozoans, molluscs, polychaetes, crustaceans, ascidiaceans and fish), are reported from the Apulian coast of Italy. Shipping, aquaculture and migration through the Suez Canal are the main pathways of introduction of the NIS. In Apulian waters, 21% of NIS are occasional, 18% are invasive and 61% are well-established. It is highly probable that more NIS will arrive from warm-water regions, because Mediterranean waters are warming. Furthermore, some of the successful NIS must have the ability to become dormant in order to survive adverse conditions, either seasonal or during long journeys in ballast waters. The identification of NIS depends greatly on the available taxonomic expertise; hence the paucity of taxonomists hinders our knowledge of NIS in our seas. We propose the creation and maintenance of a network of observatories across the Mediterranean to monitor the changes that take place along its coasts.

The rediscovery of Codonorchis octaedrus (Hydroidomedusae, Anthomedusae, Pandeidae), with an update of the Mediterranean hydroidomedusan biodiversity

Abstract Codonorchis octaedrus is recorded for the first time since its discovery by Haeckel in 1879. A hydroid colony collected in a cave of the Apulian Coast (between the Ionian and the Adriatic Seas) produced several medusae which have been reared to maturity. This is the first complete description of the species, which was previously considered as doubtful, as was the genus Codonorchis. The diagnostic features for the genus are: hydroid small, naked, sessile, with a single row of few tentacles, gono‐phores on hydrorhiza, medusa with apical projection with apical process from the manubrium, perradial, interradial and adradial ocellate bulbs, two perradial tentacles, horseshoe‐shaped interradial gonads, small mesenteries. The list of Mediterranean hydroidomedusae is updated with the new (or overlooked) records since the last published list (1993). The increase in species number is great (about 10%), showing that the knowledge of biodiversity of even a well‐studied sea as the Mediterranean is far from be...

Recruitment of Serpuloidea (Annelida: Polychaeta) in a marine cave of the Ionian Sea (Italy, central Mediterranean)

This paper is the first attempt to study the recruitment of Serpuloideans in a Mediterranean marine cave through the use of artificial substrates placed in three different positions, from the entrance to the interior of the cave. This study provides qualitative and quantitative data concerning Serpuloidea recruitment on panels removed successively after one, three, six and 12 months of permanence in the cave. A homogeneous distribution of juveniles Spirorbidae throughout the cave axis had already been detected after one month of panel immersion. Spirorbids were recorded also on panels removed after three months as well as serpulids, which began to be detected during this sampling time, even though represented by just one species. A significantly different pattern of distribution throughout the cave axis was observed after only six months, while other serpulids were detected for the first time. The pattern of species distribution seemed to reflect the biotic and environmental conditions of the cave. The highest serpuloidean species abundance and diversity was found on panels placed in the intermediate position within the cave. After only one year of panel immersion, a total of 20 taxa (11 Serpulidae and 9 Spirorbidae) was recorded, including five species listed for the first time in the marine caves of the Salento Peninsula.

Life cycle of Bougainvillia nana (Cnidaria: Hydrozoa: Bougainvilliidae) from Italy, including a discussion of Bougainvillia muscus in the Mediterranean Sea

The life cycle of a species of the genus Bougainvillia (Cnidaria: Hydrozoa), found in the southern Mediterranean Sea, Italy, is here described. Hydroid colonies produced immature medusae with two tentacles and two ocelli per bulb and four unbranched oral tentacles. The number of tentacles and ocelli, which remained constant during the entire life cycle, are here considered diagnostic characters to identify the present as a new species. Female medusae lived up to 47 days (with an average of 30 days) when reared at 17 °C, while males, reared at the same temperature, were short-lived, concluding their life cycle in no more than 15 days. The medusa of this species resembles B. ramosa var. nana described by Hartlaub in 1911 on the basis of few specimens and no polyp stage. After the complete life cycle has been observed, and given its peculiar medusa stage, Hartlaubs subspecies (variant) must be promoted to species rank as Bougainvillia nana.

Composition and Spatial Distribution of Mesozooplankton along Confinement and Anthropogenic-Impact Gradients in the Gulf of Vlorë (Albania)

ABSTRACT Belmonte, G.; Moscatello, S.; Hajdëri, E.; Vaglio, I., and Denitto, F., 2018. Composition and spatial distribution of mesozooplankton along confinement and anthropogenic-impact gradients in the Gulf of Vlorë (Albania). The composition of mesozooplankton and their space-time distribution in the Gulf of Vlorë (southern Albania, Mediterranean Sea) are described for the first time. Sampling was carried out during two oceanographic cruises (May 2007, January 2008) with two replicates at each of 17 stations at each time, making a total of 68 samples. The study aimed to describe the influence of confinement (defined as distance from the open sea) and anthropogenic impact (defined as vicinity to the east coast of the gulf) on zooplankton composition. A total of 198 taxa were recognised in the whole zooplankton assemblage, with only 136 taxa common to both periods and only two species present in all samples. Statistical analysis of data distinguished the Mezokanal area (the boundary between the gulf and the open sea) from three other areas inside the gulf. Differences were also found among the areas inside the gulf at increasing degree of confinement. Mesozooplankton varied more sharply with confinement than with anthropogenic impact and yielded more-detailed space partitioning of the gulf than microzooplankton, which had been used in a previous study.