Papers by Primo Micarelli
Mediterranean Marine Science
Stable isotopes (δ13C and δ15N) were analysed in vertebrae of Scyliorhinus canicula (n=40; 13 mal... more Stable isotopes (δ13C and δ15N) were analysed in vertebrae of Scyliorhinus canicula (n=40; 13 males, 27 females) from the central Tyrrhenian Sea to explore a potential trophic shift in relation to sex and maturity condition. Isotopic values were obtained from the centre and the periphery of the vertebra of each individual to test for the effect of maturity condition. The values of δ13C and δ15N showed significant differences between the immature and mature state of the individuals analysed (U’=1392, P<0.0001 for δ13C; U’=1385, P<0.0001 for δ15N). Differences in values of δ15N demonstrated a trophic shift during maturation progress of S. canicula. The peripheral vertebral part, corresponding to the mature state of each individual, showed higher values of δ15N (mean 5.41‰ SD±1.29‰), compared with the lower values of δ15N (mean 2.78‰ SD±1.52‰) observed in the central vertebral part related to the immature state. In contrast, the isotopic signature of δ13C was lower in the vertebr...
Biology, Nov 29, 2022
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
2022 IEEE International Workshop on Metrology for the Sea; Learning to Measure Sea Health Parameters (MetroSea)
Estuarine, Coastal and Shelf Science
The origin of a population of great white sharks (GWS), Carcharodon carcharias, L.1758, residing ... more The origin of a population of great white sharks (GWS), Carcharodon carcharias, L.1758, residing in the Mediterranean Sea has remained a mystery despite repeated scientific endeavours to retrace their history. Here we analyze 18 historical specimens (30-180 years old) collected from several museums, research institutes and private collections in Italy, creating the largest dataset of Mediterranean GWS mitochondrial DNA gene sequences (i.e. D-loop and COI). Comparative phylogenetic analyses of the Mediterranean GWS with populations from global range suggested a closer evolutionary relationship with sharks in Australia- New Zealand, Japan and the Pacific US rather than to the South-African population. Estimates of the most recent common ancestor carried out using internal calibration with fossil and paleo-geographical data revealed that Mediterranean GWS population originated in the early Pliocene at the end of the Messinian Salinity Crisis (ca. 5.3 MYA). This dating supports a GWS hi...
CBM - Cahiers de Biologie Marine, 2018
The paper confirms the presence of Alopias superciliosus in the Tyrrhenian Sea, giving useful inf... more The paper confirms the presence of Alopias superciliosus in the Tyrrhenian Sea, giving useful information for a species assessed as "vulnerable" worldwide and "data deficient" for the Mediterranean Sea by IUCN. In the stomach of this shark, 25 specimens of Pseudophyllidea, 4 of Trypanorhyncha and 3 of Anisakis spp. were found. In the gut, the presence of 20 specimens of Litobothrium spp. was observed. Since this is the first evidence of the presence of the genus Litobothrium in the Mediterranean Sea, the paper demonstrates a range expansion of this parasite from the Pacific.
Much of the knowledge we have on the elasmobranchs was built by research carried out within the a... more Much of the knowledge we have on the elasmobranchs was built by research carried out within the aquaria in controlled conditions [1-7]. The small spotted catshark (Scyliorhinus canicula, Linnaeus 1758) is a common host of many aquaria through Europe. It is a widespread elasmobranch in the North East Atlantic Ocean: from Norway to Senegal, including the Mediterranean Sea [8]. It is a species of significant commercial importance in countries like the UK where it is abundant and used for fish meal [9]. In other areas, this benthic shark is a catch accessory, and used as a fresh product or in salt and to produce oil.
Diversity
Knowledge about the social behavior of sharks is a growing research field, but not many observati... more Knowledge about the social behavior of sharks is a growing research field, but not many observations are available on the social interactions between pairs of sharks in the presence of passive surface bait and mainly related to aggregations. Between 2009 and 2018, in Gansbaai, South Africa, 415 white sharks were sighted, and 525 surface-generated social interactions were identified, exhibited by 169 different white sharks. The mean sighting rate was 0.91 (range 0.18–1.53) white sharks per hour. Eight patterns of social interaction were exhibited: swim by, parallel swim, follow/give way, follow, give way, stand back, splash fights, and piggyback. Non-random interactions occurred when pairs of specimens approached the passive surface bait, confirming that the white sharks made a real choice, showing a dominance hierarchy during the ten years of data collection. Evidence of non-random social interactions in the surface behavior of bait-attracted white sharks Carcharodon carcharias in G...
Biology, Apr 26, 2022
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
The Nursehound, Scyliorhinus stellaris (Linnaeus, 1758), is a benthonic catshark present inshore ... more The Nursehound, Scyliorhinus stellaris (Linnaeus, 1758), is a benthonic catshark present inshore and offshore in the northeast and eastern central Atlantic, over the continental shelf between southern Scandinavia and Senegal, and is also distributed throughout the Mediterranean. This species is fished by bottom trawls, gill nets, bottom set long lines, handlines and fixed bottom nets, and occasionally by pelagic trawls. Although limited data are available on the exploitation and trends in abundance, declines have been indicated in the Mediterranean Sea, particularly around the Balearic Islands and in the northwest Mediterranean. The capacity for resilience of this species is affected by a low level of interconnectivity between isolated populations around islands far from the continental coast. Few informations are available on its biology; however, it is a large bodied species and is likely more vulnerable to population depletion than the Smallspotted Catshark (S. canicula), which also occurs in the region. Given its large size, patchy distribution and evidence of decline in the Mediterranean Sea, an assessment of at least Near Threatened is warranted (IUCN Red List. 2009). In 2018 Sharks Studies Centre activated a new project aimed at locating, around Monte Argentario Pensinsula in Tuscany (Ita), the presence of Nursehound Nursery using Poseidon R.O.V.(Remote operative vehicule), an underwater drone that can operate up to 120 meters deep with 5 hours of autonomy. The project, partially funded by the Tuscany Region (Go Green 2018), will allow to identify eggs spawning areas. The first 2 years of observations, 2018 and 2019, are presented and discussed.
It is known that juveniles whale sharks (Rhincodon typus) have tendency to gather, seasonally, in... more It is known that juveniles whale sharks (Rhincodon typus) have tendency to gather, seasonally, in a few coastal areas around the world to feed on zooplankton; however little is known about their food preferences. The CSS (Centro Studi Squali) scientific coordinator of the project “Whale shark feeding ecology” (in partnership with University of Calabria, University of Siena, ISPRA, University of Naples Federico II, Stazione Zoologica Anton Dohrn), in 2016, started the study of these aggregations. During field observations we collected zooplankton samples and we observed feeding behaviour of sharks to understand the main characteristics of the zooplankton community that appears to cause said gatherings. So far two expeditions (2017 and 2018) have been carried out in the channel of Mozambique, in the coastal waters of the Nosy Be (MG). Here whale sharks are present in the last four months of the year: data were collected in the eastern part of the island in late November-early December which is the peak season for whale shark sightings in the area. Zooplankton samples were collected vertically from 10 m depth to surface, using a net with 200 μm mesh aperture. The samples were concentrated using a 50μm filter and fixed with alcohol (70%) and lugol (1%). At the same time, location, water temperature and transparency, shark presence/absence and feeding behaviour were recorded. Quantitative and qualitative analysis of zooplankton samples were performed at Stazione Zoologica Anton Dohrn and ISPRA laboratories. We calculated zooplankton biomass and abundance. We identified at species level the most important zooplanktonic taxa (copepods, chetognats etc) and moreover we calculated their size spectra.
Maturation and fertilisation in vitro of Pecten maximus oocytes using serotonine and dopamine ago... more Maturation and fertilisation in vitro of Pecten maximus oocytes using serotonine and dopamine agonists
Grey reef sharks (Carcharhinus amblyrhynchos), are included in the IUCN red list as near threaten... more Grey reef sharks (Carcharhinus amblyrhynchos), are included in the IUCN red list as near threatened, however, their biology is still relatively little known. Discordant data are available on their tendency to be site fidelity, studies carried out in Australia indicate limited reef fidelity and evidence of largescale movements within northern Australian waters, while site fidelity and residency of grey reef sharks on the outer slope of coral reefs in Palau, Micronesia, over a period of two years and nine months were detected regularly throughout another study and sharks displayed strong inter-annual residency with greater attendance at monitored sites during summer than winter months. However, it is commonly believed that Grey reef sharks display strong levels of site fidelity that persist across years, at least for some components of the population. Site fidelity is a common phenomenon in many species, including whitetip (Triaenodon obesus), tawny nurse (Ginglymostoma cirratum), blacktip (Carcharhinus melanopterus), Caribbean (C. perezi) and grey reef (C. amblyrhynchos) sharks. The degree of fidelity appears to vary according to life history stage, availability of resources and area of suitable habitat. Site fidelity is also common in adult reef sharks, although typically more sporadic when compared to juveniles, which might be partially explained by ontogenetic increases in the size of home ranges. Off Nosy be in Madagascar in the Mozambique channel, we have identified a new probable nursery that is being monitored by CSS (Centro Studi Squali) since 2017, thanks to the logistical and underwater support of the Manta Diving. Around the pinnacle of a coral reef at about 15-30 meters depth, grey reef sharks patrol daily, specimen sizes between 50cm and 200cm. The importance of identifying and reporting nursery areas for this species, is a priority to promote its proper conservation.
DURING 4 STUDY EXPEDITIONS IN SOUTHAFRICA, PERFORMED IN 2000, 2003, 2004 AND 2005, OBSERVATIONS A... more DURING 4 STUDY EXPEDITIONS IN SOUTHAFRICA, PERFORMED IN 2000, 2003, 2004 AND 2005, OBSERVATIONS ABOUT SURFACE PREDATORY BEHAVIOUR OF THE GREAT WHITE SHARK IN PRESENCE OF PASSIVE PREYS WERE MADE. OBSERVATIONS WERE CARRIED OUT BY UNLIMITED SHARK DIVING BOATS AND BY CAGE DIVING AROUND DYER ISLAND, ABOUT 5 MILES FAR FROM GANSBAAI. DURING THE 27 OBSERVATION DAYS WERE IDENTIFIED 78 DIFFERENT SPECIMENS, THAT EXHIBITED 8 DIFFERENT BEHAVIOURS. THE GREAT WHITE SHARK POPULATION OBSERVED AROUND DYER ISLAND SHOWS A GREATER VARIETY OF BEHAVIOURS THAN THE POPULATION STUDIED ALONG THE CALIFORNIA COASTS.
Notes on the immigrant fish from the Red Sea belonging to the species Fistularia commersonii (Rup... more Notes on the immigrant fish from the Red Sea belonging to the species Fistularia commersonii (Ruppel,1835) (Fistularidae, Pisces), fished in waters of the North Tyrrhenian Sea. This specimen has been catched from a fishing vessel, along the coast of Monte Argentario (Italy), in october 2004.
In Freecciolosa Pond, Orbetello Lagoon (Central Italy), Gracilaris verrucosa, is utilised forn co... more In Freecciolosa Pond, Orbetello Lagoon (Central Italy), Gracilaris verrucosa, is utilised forn controlling nutrients in an integrated system with intensive rearing in enclosures. gracilaria is periodically exported with a yeld of 3.876 kg/ha/month and its ability to utilise nutrients is confirmed by the control of local Health Authority.
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Papers by Primo Micarelli