Copepods of the family Pandaridae are typically ectoparasites of elasmobranch fishes. They display a cosmopolitan distribution and limited host specificity. Published literature on their occurrence ...on pelagic sharks in the Mediterranean is scarce, often from the past century, or scattered through fish parasite surveys. Moreover, of the 64 valid pandarid species known at present, molecular data from GenBank exists for only 10 species and there are no data from the Mediterranean. In this study, we begin addressing this knowledge gap by exploring the molecular features of some pandarid copepods (i.e.,
Dinemoura latifolia
,
Echthrogaleus coleoptratus, Pandarus satyrus
, and
Phyllothyreus cornutus
) and their phylogenetic relationships using new material from pelagic sharks (i.e.,
Prionace glauca
,
Isurus oxyrinchus
, and
Carcharodon carcharias
) in the Mediterranean. Genetic distances analysis showed intraspecific variation in the mitochondrial DNA cytochrome oxidase
c
subunit 1 (mtDNA
cox
1) sequences and interspecific variations of 0.001–0.081 and 0.196–0.288, respectively, for the small subunit ribosomal DNA (SSU rDNA) and the
cox
1 gene locus. Phylogenetic analyses of pandarid copepods based on sequences available in GenBank plus the sequences generated by our study revealed two major clades: the first, with strong nodal support, included species of
Pandarus
,
Phyllothyreus
,
Pannosus
, and
Pseudopandarus
; the second, with weaker nodal support, included species of
Achtheinus
,
Perissopus
,
Echtrogaleus, Nesippus
, and
Dinemoura.
As most pandarid species are missing from the present analyses, we discuss the limitations of our phylogenetic results. Nevertheless, this study represents a first step toward to yielding new information about the phylogeny of parasitic copepods on pelagic sharks in the Mediterranean.
Chondrichthyans (sharks, rays, and chimaeras) are highly susceptible to the impacts of fisheries due to their vulnerable life-history traits. Over the last 100 years, several cases of local ...extinction have been documented in heavily fished areas across the Mediterranean Sea. In the Strait of Sicily (SoS), one of the main demersal fishing grounds of the Mediterranean, chondrichthyans constitute a significant component of both commercial and discarded bycatch. In this area, the lack of long-term data series on these species hinders our ability to fully comprehend the extent of changes due to both overfishing and climate variations. Here we aim to use historical data from the end of the 19th century, provided by Döderlein, to uncover evidence of long-term changes in the occurrence and diversity of these fishes. We employ a semi-quantitative approach to compare past data with recent frequency of occurrence estimates, to improve our ability to propose management advice. We report a decline in both the number of species and the frequency of occurrence of sharks and ray species in the study region over the past 150 years. Our findings shed light on the current status of sharks and rays compared to the historical data from the 19th century and highlight the urgent need to develop management strategies to mitigate the impact of harvesting on these vulnerable species.
•Historical data of the Chondrichthyans from the end of the 19th century are used to uncover evidence of changes in the occurrence of these fishes in the Central Mediterranean Sea.•A semi-quantitative approach is employed to compare past data with recent frequency of occurrence estimates, aiming to improve the ability to propose management advice.•The study shows a decline in sharks and rays over 150 years, emphasizing the urgent need for management strategies to mitigate harvesting impact on these vulnerable species.
Two juveniles Luvarus imperialis, astrodermella stage, 97.4 mm and 90.6 mm in total length, were recorded on September 2016 and August 2017 respectively, the first caught by a bottom trawler off the ...south-eastern coast of Sicily, Strait of Sicily, Italy, the second found
stranded on the beach in the nearby region. Biometrics data of this uncommon species are given and the occurrence of juvenile stages in the Mediterranean area is briefly discussed.
Dva primjerka mlađi Luvarus imperialis, (stadij astrodermella) ukupnih dužina 97,4 mm i 90,6 mm, zabilježena su u rujnu 2016., odnosno kolovozu 2017. godine. Prvi primjerak je ulovljen koćom na jugoistočnoj obali Sicilije, Sicilijski tjesnac, Italija. Drugi primjerak je pronađen na plaži u obližnjoj regiji. U ovom radu, autori navode biometrijske podatke ove neobične vrste i ukratko se raspravlja o pojavi mlađih u mediteranskom području.
PDF
