Relaciones entre talla del otolito y talla del pez en algunos peces mesopelágicos y batipelágicos del Mediterráneo (estrecho de Messina, Italia)

The length-weight relationships and the regressions between otolith size (length and width) and fish length of some mesopelagic and bathypelagic fishes living in the central Mediterranean Sea were provided. Images and morphological description of otoliths (sagittae) from 16 species belonging to the families of Gonostomatidae (1), Microstomatidae (2), Myctophidae (8), Phosichthyidae (2), Sternoptychidae (2) and Stomiidae (1) were given. The length-weight relationship showed an isometric growth in 13 species. No differences between right and left otolith sizes were detected by t-test, so a single linear regression was plotted against standard length (SL) for otolith length (OL) and otolith width (OW). Data fitted well to the regression model for both OL and OW to SL, for each species (R2 > 0.8). These relationships offer a helpful tool in feeding studies and also provide support to palaeontologists in their research on fish fossils.En este trabajo se presentan las relaciones talla-peso y las regresiones entre la talla del otolito (longitud y anchura) y la talla del pez (SL) para algunos peces meso y batipelágicos que viven en el Mediterráneo central. Se incluyen imágenes y descripciones morfológicas de los otolitos (sagittae) de 16 especies de las familias Gonostomatidae (1), Microstomatidae (2), Myctophidae (8), Phosichthyidae (2), Sternoptychidae (2) y Stomiidae (1). La relación talla-peso muestra un crecimiento isométrico en 13 especies. No se encontraron diferencias relevantes (t-test) entre la talla del otolito derecho e izquierdo, por lo que se representó una sola regresión lineal entre la longitud estándar y los siguientes parámetros: longitud de otolite (OL) y la anchura (OW). Los datos se ajustaron bien al modelo de regresión lineal para OL y OW, para todas las especies (R2 > 0.8). Las relaciones obtenidas puede ser utilizadas como instrumento en estudios de alimentación y para sustentar estudios de paleontología sobre peces fósiles

Prvi nalaz plavog raka Callinectes sapidus Rathbun, 1896 (Crustacea: Brachyura: Portunidae) u vodama pokrajine Abruzzi, srednji Jadran

For the first time, one female individual of blue crab Callinectes sapidus Rathbun, 1896, a species native to the western Atlantic coasts, is reported from Abruzzi waters (central Adriatic Sea). This species has widely invaded European Atlantic coasts and several areas of the Mediterranean, probably brought by ballast waters; yet, it has not settled in the study area.Po prvi put, jedinka ženke plavog raka Callinectes sapidus rathbun, 1896 vrste koja potječe sa zapadne obale atlantika, zabilježena je u vodama pokrajine abruzzi (srednji Jadran). Ova vrsta je uvelike najezdila europske obale atlantika i nekoliko područja u mediteranu, donešena vjerojatno balastnim vodama; ipak, još se nije u potpunosti nastanila u istraživanom području

Documenting the occurrence of the Lessepsian fish Stephanolepis diaspros within the Strait of Sicily, Central Mediterranean

The increasing occurrence of the reticulated leatherjacket, Stephanolepis diaspros (Tetraodontiformes, Monacanthidae), a Lessepsian migrant, within the Strait of Sicily, central Mediterranean, is documented in this study. This is done through the collation of records of the species from coastal waters off the Maltese Islands, collected between August 2007 and May 2011, and through the publication of the second validated record for the same species, collected on 10 December 2013 from the island of Lampedusa (Pelagian Islands).peer-reviewe

Marine caves of the Southern Tyrrhenian Sea: a First Census of BenthicBiodiversity

This is the first paper documenting research on a selection of marine caves located along the coast of Capo Milazzo in the southern Tyrrhenian Sea. Three submarine and one semi-submerged caves were surveyed and sampled using underwater photo sampling. Surveys have only taken into account the sessile species belonging to the main taxa: Porifera, Anthozoa, Bryozoa and Polychaeta. Diversity indices and abundances were calculated for three sections within each explored cave: the Entrance Zone, Intermediate Zone and Bottom Zone. The richest group was Porifera with 21 taxa, followed by cnidarians, (Anthozoa), with 8 taxa, Polychaeta (5 taxa), and Bryozoa (5 taxa). Among Porifera, the presence of Petrobiona massiliana, a protected species according to SPA/BIO Protocol and the Bern Convention, must be highlighted. The encrusting forms were dominant in the Bottom Zone, the massive forms in the Intermediate Zone and the arborescent forms in the Entrance Zone. Generally, the percentage coverage of each morphological group showed a decline in the Intermediate Zone and a general increase in the Dark Zone within each cave. The S, H’ and J values showed different trends in the five caves. These differences, also evidenced by Permanova analysis, depend on the topographic specificity of each cave which, in turn, affects the gradients of the biotic and abiotic parameters. Finally, no horizontal gradient of rarefaction of the benthic sessile fauna has been detected. This study represents an important step for the management and conservation practices of these fragile ecosystems, especially in view of the forthcoming establishment of the Marine Protected Area

New records of the silver-cheeked toadfish Lagocephalus sceleratus (Gmelin, 1789) in the Tyrrhenian and Ionian Seas: early detection and participatory monitoring in practice

5 pages, 3 figuresThe silver-cheeked toadfish Lagocephalus sceleratus (Gmelin, 1789)—an invasive toxic species well established in the eastern Mediterranean—is rapidly expanding through the western Basin and a public campaign was set to inform Italian citizens on the risks associated with its consumption. Both news media and local communities responded rapidly to the initiative generating an increasing flow of information. On 15 April 2016, a new capture of this species (off Briatico, Calabria, Italy at 25 m of depth), was promptly reported to the authors, representing the first documented record of L. sceleratus from the Tyrrhenian Sea. On 7 June 2016, a second specimen was captured at Montebello Ionico in Calabria. This case of early detection is here presented as a successful example of interplay among citizens, researchers, and policy makers: a powerful approach for monitoring the spread of invasive species and reducing their potential impacts through increasing awarenessPeer Reviewe

Alohtone vrste glavonožaca u Sredozemnom moru: pregled

The present review critically assesses the records of cephalopods that have entered the Mediterranean Sea in the last few decades. It includes 13 species, namely Sepia dollfusi, Stoloteuthis leucoptera, Sepioteuthis lessoniana, Architeuthis dux, Cranchia scabra, Taonius pavo, Megalocranchia sp., Teuthowenia megalops, Cycloteuthis sirventi, Taningia danae, Octopus cyanea, Amphioctopus sp. and Tremoctopus gracilis. The presence of Sepia pharaonis needs to be confirmed, whereas that of Sepia gibba and Spirula spirula is excluded. The arrivals from the Atlantic Ocean through the Strait of Gibraltar are related to the entrance surface current, which either carried passively planktonic paralarvae or favoured in some other way the entrance of subadult and adult stray specimens. As a matter of fact, all Atlantic cephalopods are pelagic oegopsid squids, with the exception of the nekto-benthic sepiolid S. leucoptera; all of them have been found only in the western Mediterranean basin. None of them seemingly established a stable population there, apart from the latter species. On the contrary, the cephalopods entering the Mediterranean from the Red Sea through the Suez Canal (Lessepsian migrants) lead a benthic mode of life. At least two of them, namely S. lessoniana and Amphioctopus sp., set up stable populations in the eastern basin. Lastly the occurrences of the pelagic octopod T. gracilis are ascribed, in the literature, to human-mediated transfer.U ovom radu autori kritički procjenjuju nalaze glavonožaca koji su ušli u Sredozemno more u posljednjih nekoliko desetljeća, što uključuje 13 vrsta, a to su: Sepia dollfusi, Stoloteuthis leucopte-ra, Sepioteuthis lessoniana, Architeuthis dux, Cranchia scabra, Taonius pavo, Megalocranchia sp., Teuthowenia megalops, Cycloteuthis sirventi, Taningia danae, Octopus cyanea, Amphioctopus sp. i Tremoctopus gracilis. Prisutnost vrste Sepia pharaonis treba biti potvrđena, dok je prisutnost Sepia gibba i Spirula spirula isključena. Dolasci vrsta iz Atlantskog oceana kroz Gibraltarski tjesnac povezani su s ulaznom površinskom strujom koja je nosila pasivno planktonske paralarve ili je na neki drugi način favorizirala ulaz subadultnih i odraslih zalutalih primjeraka. Zapravo su svi atlantski glavonošci pelagične lignje, s izuzetkom nekto-bentoskog sepiolida S. leucoptera. Čini se da nijedna vrsta od navedenih tamo nije uspostavila stabilnu populaciju, osim potonje navednih vrsta. Naprotiv, glavonošci koji ulaze u Sredozemno more iz Crvenog mora kroz Sueski kanal (lesepsijski migranti) vode bentoski način života. Ipak, dvije vrste S. lessoniana i Amphioctopus sp., uspostavile su stabilne populacije u istoč-nom dijelu. Konačno, pojave pelagične hobotnice T. gracilis pripisuju se, u literaturi, prijenosu posredovanim antropogenim utjecajem

Dieta del pez de San Francisco Synodus saurus (Linnaeus, 1758) (Pisces, Synodontidae) en el Mediterráneo central

The diet composition of the Atlantic lizardfish Synodus saurus, caught on sandy bottoms of the north-western coast of Sicily (southern Tyrrhenian Sea) is described. The stomachs of 224 specimens (from 73 to 280 mm TL) were collected between June 2005 and May 2006. The analysis of stomach contents showed that this species is almost exclusively piscivorous. Unlike other benthic predators of the study area, it mainly feeds on pelagic school-forming fish, such as Clupeidae, Engraulidae and Myctophidae and juveniles of Sparidae and Centracanthidae, and benthic prey play a secondary role. The diet of S. saurus is related to the seasonal availability of resources, depending on the occurrence of juveniles of several species and on the migration of pelagic fishes in the study area. There were no significant changes in prey items between predator length groups, but a positive, significant linear relationship between prey size and predator size was recorded.El presente trabajo ha estudiado la composición de la dieta del pez de San Francisco Synodus saurus, pescado sobre fondos arenosos en la costa nor-occidental de Sicilia (Tirreno meridional). El análisis del contenido estomacal de 224 individuos (entre 73 y 280 mm LT), pescados entre junio 2005 y mayo 2006, evidenció que S. saurus es una especie casi exclusivamente ictiófaga. A diferencia de otros depredadores bentónicos, S. saurus se alimenta fundamentalmente de peces que forman bancos pelágicos como Clupeidae, Engraulidae y Myctophidae y de los juveniles de las familias Sparidae y Centracanthidae, mientras las presas bentónicas resultaron secundarias. S. saurus exhibió una estrategia alimentaria relacionada con la disponibilidad estacional de recursos, dependiendo de la ocurrencia de juveniles de varias especies y de la migración de peces pelágicos en el área de estudio. No hubo cambio significativo de presas entre grupos de tallas pero se evidenció una relacción positiva, lineal y estadísticamente significativa entre el tamaño de la presa y del depredador

Assessing worth of marine protected areas for the protection of threatened biodiversity using IUCN Red List and Red List Index. A pilot study in six mediterranean areas

Abstract The Mediterranean marine region is considered one of the world's biodiversity hotspots for conservation priorities due the high occurrence of rare and threatened species, endemism and high species richness. However, several pressure such as losses and alterations of habitats are ongoing and in order to increase conservation in this sea region, many marine protected areas were established, including Natura 2000 sites. The latter are areas designated under the Habitat and Bird Directives for the conservation of species in need of strict protection, so that they can reach a favourable conservation status. Species conservation status is also assessed through the IUCN (International Union for Conservation of Nature) Red List of Threatened Species. The aim of our study was to test whether IUCN Red List and the related Red List Index RLI (which aggregates in a single value all the information on conservation status of a particular set of species) can be used as a metrics to characterize MPAs, and orienting, consequently, local marine conservation policies. A pilot study was undertaken in the six Sicilian MPAs (Marine Protected Areas) and results highlighted that Egadi Island has a low RLI value (meaning that the MPA hosts many species with a threatened status) while the Capo Gallo MPA, at the opposite, as an high RLI value (i.e.less threatened species); the other four MPAs. Egadi, Pelagie, and Ustica showed similar distribution frequencies of Red List categories having similar RLI values. Biological resource use, natural system modifications, invasive species, and pollution all account for 90% of assessed threats. Outcomes of our study showed that IUCN indicators should be considered as a tool to: assess the conservation status of set of species in protected areas; drive prioritization in the decision process in order to support an effective management conservation plan; designate new MPAs

Notes on the reproductive condition of early colonizing S. Luridus in the Sicily Strait (Mediterranean Sea)

This paper summarizes some observations on gonad development and fecundity of the Lessepsian migrant Siganus luridus (Osteichthyes: Siganidae), recently settled in the islands of Malta and Linosa (Sicily strait, Mediterranean sea). The analysis of ovarian and testicular development showed that these early colonizers attain final gonad maturation and have the potential for successful reproduction.peer-reviewe