The largescaled terapon Terapon theraps: a new Indo‐Pacific fish in the Mediterranean Sea

A specimen of the largescaled terapon Terapon theraps was recorded for the first time from the Mediterranean Sea. The finding of T. theraps in the northernmost part of the Mediterranean Sea raises the number of Lessepsian migrant species to at least 68 and in the Adriatic Sea to at least 11.     

The trophic role of the marine cladoceran Penilia avirostris in the Gulf of Trieste

The herbivory of the marine cladoceran Peniliaavirostris was studied in the Gulf of Trieste(Northern Adriatic) from June 1993 to December1994 using the gut fluorescence method. P. avirostrisoccurred from June to December, butreached its greatest abundance in the summer months.A significant correlation between the gut pigmentcontent and chlorophyll a concentration in thesurface layer was established. Observations with anepifluorescence microscope revealed that the guts werefilled with fluorescing nanoplankton and picoplankton(cyanobacteria). Quantitative estimates indicated thatP. avirostris grazed less than 5% of theavailable chlorophyll a in more than half of allmeasurements, but removed most of the availablechlorophyll a in the surface layer during someperiods in September. It can therefore be concludedthat P. avirostris, together with planktonicprotists, plays an important role within the microbialloop.     

Prevalence of antibodies to porcine parvovirus in wild boars (Sus scrofa) in Croatia

Serologic evidence of exposure to porcine parvovirus (PPV) in the wild boar (Sus scrofa) in Croatia was investigated. Serum samples from 219 wild boars captured during 2003 from 12 different locations in the Republic of Croatia were tested by using a commercial enzyme-linked immunoassay (ELISA) and a hemagglutination inhibition (HI) test. Antibodies to PPV were detected in 91 (41.6%) of tested samples and positive results were detected in wild boar from all sample locations. Adults had a significantly higher prevalence (70%) than juveniles (31%; P < 0.01). Our results indicate that wild boar populations throughout the Republic of Croatia are exposed to PPV.     

Cage culture effects on mullets (Mugilidae) liver histology and blood chemistry profile

A comparative study of blood chemistry and histology was conducted on two groups of mullets (Mugilidae) living under different conditions with different feed sources. The aquaculture influenced mullet group (AIM), was collected near fish farms and the control group of mullet (CM) was caught in the waters without any aquaculture activities. Histological and biochemical procedures were employed to study liver histomorphology, plasma aspartate and alanine aminotransferase (AST, ALT), triglyceride (TRIG), cholesterol (CHOL), glucose (GLU) and total protein (TP) of both AIM and CM. Moderate histological changes (lipid infiltration) were observed in the liver of AIM. Significant changes in plasma variables were observed in AIM. Blood chemistry variables measured proved to be good indicators of artificial feed effects. Classical statistical approaches were applied to the blood chemistry and histopathology data. For the first time machine learning techniques were used to generate comprehensible classification models and to explore blood chemistry variable importance, strength, their mutual interactions or dependencies, and to investigate reliability of particular variables within the groups.     

The ecology of the Mediterranean stony coral Cladocora caespitosa (Linnaeus, 1767) in the Gulf of Trieste (northern Adriatic Sea): a 30-year long story

Cladocora caespitosa is an endemic coral of the Mediterranean Sea and an important carbonate bioconstructor that adds 3D complexity to the habitat, thus increasing marine biodiversity. Despite its important role in the ecosystem, the real status of the population along most of the Mediterranean coastline is still poorly investigated and very little is known about the resilience of the species. Using non-destructive visual surveys, colonies of C. caespitosa were investigated by SCUBA diving in 2013 and 2015 at seven sites of the northern Adriatic Sea (southern part of the Gulf of Trieste). Data about colony size, index of sphericity and corallite diameter were collected. Almost all biometrical parameters differed significantly among sampling sites, showing low occurrence of the larger size classes compared to the abundance of small-sized colonies. This pattern of distribution is typical of long-lived organisms. The positively skewed colony size distribution could be due to both a high mortality rate of small colonies unable to reach larger size classes, and to a high fragmentation rate of colonies, related to a strong hydrodynamic forces. The northern Adriatic population of C. caespitosa has previously been investigated by Schiller, who reported size and abundance data of colonies from one site, at a depth range of 2–5?m. We compared these data with our findings from the same sampling site, adding new information about the ecology of C. caespitosa. After a 30-year period, the comparison shows a change in the size distribution of colonies, with a decrease of the small class and an increase of the medium class of colonies. In view of these conclusions, further assessments are required in order to evaluate the trend of the northernmost C. caespitosa population in the Mediterranean Sea.     

Incidence of leptospiral antibodies in different game species over a 10-year period (1996–2005) in Croatia

During the 10-year survey (1996–2005), a total of 868 blood samples from different game species in Croatia were analyzed for the presence of leptospiral antibodies. The specific antibodies (AB) were detected in 242 samples (27.88%). According to the species in red deer (Cervus elaphus), the antibodies against six different leptospiral serovars were found in 43 of 226 analyzed sera (19.02%). The most frequent antigen serovars in the deer population were Pomona and Ballum (with the same frequency of 23.6%), whereas the highest titer was recorded for serovar Sejroe (1:800). In the analyzed roe deer (Capreolus capreolus) serum samples, a low level of leptospiral antibodies (6.07%) was determined, with just two AB for antigen serovars—Australis and Sejroe. In wild boar (Sus scrofa), leptospiral antibodies were detected in 151 of 431 samples analyzed (35.03%), with AB for nine antigen serovars. The serovars most frequently found were Australis (48.70%) and Pomona (22.70%), and these serovars also recorded the highest titer (1:3,200). Among brown bear (Ursus arctos) samples, leptospiral antibodies were detected in 25.00% of the samples, with four AB for antigen serovars, of which the most frequent was Icterohaemorrhagiae (>40%). This serovar had the highest recorded titer (1:400). From 112 analyzed red fox (Vulpes vulpes) samples, leptospiral antibodies were found in 35 samples (31.25%). The determined antibodies were specific for four antigen serovars, of which the most frequent (46.2%) and with highest titer (1:1600) was serovar Australis. No antibodies (28/0) were recorded in mouflon (Ovis musimon). The most important game species from an epizootiological point of view in the studied area were certainly wild boar and red foxes. With strong serological reactions, these two species could be emphasized as important hosts for Leptospira interrogans sv. Australis in Croatia, but for their declaration as ‘maintaining hosts,’ isolation of sv. Australis is needed. According to aerial distribution, the highest number of positive samples from different game species was recorded in the central and eastern parts of Croatia, known as the ‘historical natural foci’ of leptospirosis—the regions of Posavina, Podravina, Slavonija, and Baranja. In contrast, the areas of Kordun and Gorski Kotar are declared as leptospira low-risk regions for the game species studied.     

Climate change,biological invasions,and the shifting distribution of Mediterranean fishes: A large‐scale survey based on local ecological knowledge

Climate change and biological invasions are rapidly reshuffling species distribution, restructuring the biological communities of many ecosystems worldwide. Tracking these transformations in the marine environment is crucial, but our understanding of climate change effects and invasive species dynamics is often hampered by the practical challenge of surveying large geographical areas. Here, we focus on the Mediterranean Sea, a hot spot for climate change and biological invasions to investigate recent spatiotemporal changes in fish abundances and distribution. To this end, we accessed the local ecological knowledge (LEK) of small‐scale and recreational fishers, reconstructing the dynamics of fish perceived as “new” or increasing in different fishing areas. Over 500 fishers across 95 locations and nine different countries were interviewed, and semiquantitative information on yearly changes in species abundance was collected. Overall, 75 species were mentioned by the respondents, mostly warm‐adapted species of both native and exotic origin. Respondents belonging to the same biogeographic sectors described coherent spatial and temporal patterns, and gradients along latitudinal and longitudinal axes were revealed. This information provides a more complete understanding of the shifting distribution of Mediterranean fishes and it also demonstrates that adequately structured LEK methodology might be applied successfully beyond the local scale, across national borders and jurisdictions. Acknowledging this potential through macroregional coordination could pave the way for future large‐scale aggregations of individual observations, increasing our potential for integrated monitoring and conservation planning at the regional or even global level. This might help local communities to better understand, manage, and adapt to the ongoing biotic transformations driven by climate change and biological invaders.