Comparison of growth rates estimated by otolith reading of Scorpaena porcus and Scorpaena notata caught on artificial and natural reefs of the northern Adriatic sea

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Biometrijska i biološka integrativna studija o boljem gospodarskom upravljanju morskim pužem, Nassarius mutabilis (Linnaeus, 1758)

Fishing of Nassarius mutabilis is by far the most important activity carried out by artisanal fisheries in the central and northern Adriatic Sea, accounting for more than 35% of total fishing effort and yielding from 2000 to 3000 t of landings each year. This gastropod is targeted from the beginning of autumn to the end of spring using basket traps. Despite its importance under a socio-economic point of view, the scientific studies on the biology and ecology of this species are very scarce and the failure of the current management measures could also be attributed to the scarce knowledge on the biology of this species in the area. Taking this statement into consideration, the results of the present study contribute to fill a few existing gaps and may be useful to improve the management measures currently in force. Samples were collected from March 2006– March 2008 during monthly fishing surveys and carried out using basket traps in the central Adriatic Sea. A total of 383 males (size range 7–29 mm SH) and 504 females (size range 15-32 mm SH) were caught. Mean SH (± SD) of males was 15.84±3.57 mm and mean SH of females was 25.31±3.06 mm. A significant difference in the biometric characteristics between the two sexes was discovered. The condition index (CI) showed similar seasonal trends for both sexes, with a decrease from late winter to spring followed by an increase from summer to fall - early winter. The minimum values were recorded in summer and the maximum ones in winter, following an opposite trend in respect to water temperature. In the males this trend was observed starting from size classes larger than 11 mm SH, hence this size might be very close to the size at first sexual maturity. The size at first maturity hypothesized for females (16-20 mm SH) agrees with the minimum landing size (MLS) currently established for this species (20 mm SH). The absence of small females (SH 23 mm) leads to suppose a sex reversal from male to female at around 20 mm SH. On this basis, the management measure of MLS leads to the selective retention of females and, hence, to a sexual gap between the two sexes with possible consequences on the biology of the species and the resilience of the stock. The peaks of CI observed for males and females confirmed that the spawning season of this gastropod occurs in late winter – early spring, according to the abundant presence of egg capsules attached to submerged substrates in that period at sea. Consequently, from a management point of view, it would be advisable to shorten the fishing season that at present extends from fall to later spring.Lovljenje morskog puža Nassarius mutabilis je daleko najvažnija djelatnost malog priobalnog ribolova u središnjem i sjevernom Jadranu, što čini više od 35% ukupnog ribolovnog napora s prinosom od 2000 do 3000 tone svake godine. Ovaj puž se lovi od početka jeseni do kraja proljeća pomoću vrše. Unatoč njegovoj društveno-ekonomskoj važnosti, znanstvene studije o biologiji i ekologiji ove vrste su vrlo rijetke, stoga se neuspjeh trenutnih mjera upravljanja također može pripisati oskudnom znanju o biologiji ove vrste u navedenom području. Rezultati ovog istraživanja pridonose rješavanju nekoliko postojećih nedostataka i mogu biti korisni za poboljšanje mjera upravljanja koje su trenutno na snazi. Uzorci su prikupljeni pomoću vrše (košare; pletene stupice) u razdoblju od ožujka 2006. do ožujka 2008. godine tijekom mjesečnih istraživanja u središnjem Jadranu. Ukupno su uhvaćena 383 mužjaka (raspon veličina 7-29 mm SH) i 504 ženke (raspon veličina 15 - 32 mm, SH- visina školjke-puža). Srednja visina puža (± SD - značajna razlika) mužjaka iznosila je 15,84 ± 3,57 mm, a srednja visina kućice ženki je iznosila 25.31 ± 3.06 mm. Otkrivena je značajna razlika biometrijskih karakteristika između dva spola. Indeks stanja (CI) pokazao je slične sezonske trendove za oba spola, s padom od kraja zime do proljeća, nakon čega slijedi porast od ljeta do jeseni odnosno početkom zime. Najmanje vrijednosti zabilježene su u ljeto, a maksimalne zimi, što predstavlja suprotni trend u odnosu na temperaturu vode. Kod mužjaka je ovaj trend uočen počevši od kategorije visine kućice veće od 11 mm, pa bi stoga ove veličine mogle biti vrlo blizu veličini puža kod prve spolne zrelosti. Hipotetski veličina ženki kod prve spolne zrelosti (visina kućice 16-20 mm) se slaže s veličinom minimalnog ulova (MLS) trenutno uspostavljenog za ovu vrstu morskog puža (visina kućice 20 mm). Odsutnost malih ženki (visina kućice <15 mm) i velikih mužjaka (visina kućice > 23 mm) dovodi do pretpostavke da se preokret kod muškog i ženskog spola odvija kada kućica dosegne visinu od oko 20 mm. Na temelju toga, mjera upravljanja bi trebala dovesti do selektivnog zadržavanja ženki, a time i do spolnog razdvajanja s mogućim posljedicama na biologiju vrste i održivost stocka. Vrhunac indeksa stanja uočenog kod mužjaka i ženki je potvrdio da se mriještenje ovog mekušca javlja krajem zime - početkom proljeća, u skladu s obilnom prisutnošću kapsula jajašaca pričvršćenih na potopljene supstrate u tom razdoblju. Prema tome, s gledišta gospodarskog upravljanja, bilo bi poželjno da se skrati ribolovna sezona koja se u ovom trenutku proteže od jeseni do kasnog proljeća

Novi nalaz šaruna golemog, Trachurus picturatus T. E. Bowdich, 1825 (Osteichthyes: Carangidae) u sjevernom Jadranu

The observation of a new species in a new area represents the first opportunity to follow and study the dynamics of colonization and understand how a new species arrives, what are its movements and its potential impact. The discovery of a large number of species outside their usual area of distribution is probably the most important reason for the increase in perceived biodiversity of the Adriatic ichthyofauna. A total of 4 specimens of T. picturatus were caught in the period May-June 2011 in the surroundings of an offshore gas platform in the Northern Adriatic Sea. Scientific literature depicts this species as rare in the Adriatic Sea, indicating and suggesting the Pomo Pit (Central Adriatic Sea) as the Northern latitudinal limit of its distribution. On this basis, this paper reports the first record of T. picturatus in the Northern Adriatic basin, suggesting an expansion of its spatial distribution.Promatranje nove vrste u novom prostoru predstavlja prvu priliku praćenja i proučavanja dinamike kolonizacije, te razumijevanje kako nova vrsta pristiže u prostor, kako se u njemu kreće i njen potencijalni utjecaj na prostor. Otkriće velikog broja vrsta izvan njihovog uobičajenog područja raspodjele je vjerojatno najvažniji razlog za povećanje percipirane bioraznolikosti Jadranske ihtiofaune. Ukupno 4 primjerka šaruna golemog, T. picturatus, su ulovljeni u razdoblju od svibnja do lipnja 2011. u okolici platformi plina u sjevernom Jadranu. Znanstvena literatura opisuje ove vrste kao rijetke u Jadranu, što potvrđuje Jabučku kotlinu (srednjeg Jadrana) kao sjevernu granicu njegove raspodjele. Na temelju toga, u ovom radu se iznosi prvi nalaz šaruna golemog, T. picturatus, u sjevernom jadranskom slivu, što ukazuje na širenje njegove prostorne raspodjele

“New records of rare species in the Mediterranean Sea” (October 2021)

“New records of rare species in the Mediterranean Sea” (October 2021

One year seawater temperature recording inside a breakwater area in the Northern and Central Adriatic Sea

Temperature is considered to be one of the main driving factors for faunal composition and seems to play an important role in several species, mostly evident in juveniles phases. In order to outline the thermal characteristics of an area protected by a breakwater system, the Mini-Log STAR ODDI® Data Storage Tag DST centi-TD temperature depth recorder was placed in the middle of that sea stretch. Sampling site was located at 43.6200014 latitude N, 13.426419 longitude E, at 30 cm depth. This instrument is capable of recording water temperature and pressure at 1-hour intervals. To prevent data loss due to theft/loss or depletion of the charge reserve, the instrument has been replaced at intervals and promptly replaced with an identical model. Water temperatures were recorded in the area for about one year, from 10 May 2013 to 3 April 2014, with a replacement of the DST centi-TD temperature depth recorder at 19 June 2013, 24 September 2013 and 4 December 2013. The selection of sampling site has been selected not only taking into account logistic needs but also based on the proximity with an open sea water monitoring station. In fact, the temperature data were also collected in a very close site at the 1.2 nautical miles offshore Senigallia harbor (43° 44.21'N, 13° 13.13'E) at the observation station TeleSenigallia pylon owned by the CNR-ISMAR of Ancona. This detection station is equipped with various types of multiparameter probes, including the Campbell Scientific ©, Inc. CS450 Submersible Pressure Temperature Transducer, fixed -2 m underwater and Campbell Scientific ©, Inc. CS109 Temperature Probe, fixed above sea level. All the data collected on this site have been automatically real time transmitted

Comparison of growth rates estimated by otolith reading of Scorpaena porcus and Scorpaena notata caught on artificial and natural reefs of the northern Adriatic sea

Despite the high number of studies on fish assemblages associated with artificial reefs and offshore platforms, little information exists on the growth rates of fish living on artificial and natural substrates. Age and growth was determined throughout otolith reading on two commercial scorpionfishes (Scorpaena porcus and Scorpaena notata) caught in the surroundings of artificial structures (artificial reefs and gas platforms) and natural habitats. Von Bertalanffy growth parameters were calculated for each species separately for each site. Age of S. porcus and S. notata ranged from 0 to 8 years and from 0 to 16 years, respectively. Kimura test applied to Von Bertalanffy growth curves indicated that the individuals of both species inhabiting the artificial structures had higher growth parameters than those caught in the natural habitat. The presence of artificial habitats in the northern Adriatic Sea positively affects growth rates and growth performance of both species, likely for the greater prey availability in respect to the natural open sea.<br>Apesar do elevado número de estudos sobre as assembléias de peixes associadas a recifes artificiais e plataformas offshore, existe pouca informação sobre as taxas de crescimento dos peixes que vivem em substratos artificiais e naturais. A idade e crescimento foram determinados pela leitura de otólitos em dois peixes escorpião comerciais (Scorpaena porcus e Scorpaena notata) capturados nas imediações de estruturas artificiais (recifes artificiais e plataformas de gás) e habitats naturais. Parâmetros de crescimento de von Bertalanffy foram calculadoss separadamente para cada espécie e cada local. A idade de Scorpaena porcus e Scorpaena notata variou entre 0 e 8 anos e 0 e 16 anos, respectivamente. O teste Kimura aplicado às curvas de crescimento de Bertalanffy indicaram que os indivíduos das duas espécies que habitam as estruturas artificiais tinham parâmetros de crescimento mais elevados do que dos capturados no habitat natural. A presença de habitats artificiais no norte do Mar Adriático afeta positivamente as taxas de crescimento e o desempenho de crescimento de ambas as espécies, provavelmente pela maior disponibilidade de presas em relação ao mar aberto natural

New records of rare species in the Mediterranean Sea (May 2022)

This Collective Article presents new information about the occurrence of 20 taxa that belong to six Phyla: one Cnidaria, one Ctenophora, two Annelida, four Mollusca, two Arthropoda, and ten Chordata. These records were reported from ten countries from the western to the eastern Mediterranean Sea as follows: Spain: early colonization signs of the Mar Menor lagoon by the cigar jellyfish Olindias muelleriFrance: second record of the sea chub of the genus Kyphosus in French Mediterranean watersItaly: first record of the marbled crab Pachygrapsus maurus in Sardinian watersfirst records of the polychaetes Malmgrenia polypapillata and Levinsenia tribranchiata in the Tyrrhenian Seanew record of the deep-sea squid Ancistrocheirus lesueurii in the Tyrrhenian Seafirst record of the pignosed arrowtooth eel Dysomma brevirostre in the Adriatic SeaTunisia: first documented record of the blue butterfish Stromateus fiatola and new record of the iconic great white shark Carcharodon carcharias in the Gulf of GabesSlovenia: first records of the sea slug Diaphorodoris alba and the sharpnose sevengill shark Heptranchias perloMon-tenegro: new record of the rare tope shark Galeorhinus galeusGreece: new records of the rabbitfish Chimaera monstrosa and the electric ray Tetronarce nobilianafirst published record of the nuribranch Discodoris rosiTurkey: first record of the ctenophore Hormiphora plumosa at country levelfirst records of the anomuran decapod Munida speciosa and the Mediterranean tripodfish, Bathypterois mediterraneus from the Levantine SeaCyprus: first documented record of the nuribranch Scyllaea pelagicaLeb-anon: first record of the killer whale Orcinus orca from the Levantine Sea