Spatial and temporal variations of tintinnids (Ciliata: Protozoa) in the Bay of Mersin, Northeastern Mediterranean Sea

Seasonal variations in species composition and abundance of tintinnids were investigated in the eutrophic coastal and offshore waters of Mersin Bay. Twelve sampling cruises were performed from September 2008 to February 2011. A total of 85 tintinnid taxa were identified. Among the recorded genera, agglutinated Tintinnopsis had the largest number of species (12 species), followed by hyaline loricated Eutintinnius (9 species), and Proplectella (7 species). Stenosemella ventricosa, Tintinnopsis beroidea, T. compressa, Favella azorica, and Helicostemella subulata were the dominant species during the study period. There were clear seasonal variations in species composition and abundance of tintinnids. The highest number of tintinnid species occurred in January 2009 and November 2010 in the entire study area, while the lowest species number occurred in March 2009. Morever, species numbers were higher in offshore stations than coastal stations. Some species were present in the coastal area of the bay, and other species were present offshore. The highest tintinnid abundance values were found in September 2008 (820 ind L-1) and August 2009 (749 ind L-1) at coastal stations. The high abundance values in the coastal stations indicates that an increase of tintinnids is closely related to trophic status of the marine environment. In connection with these results, correlation analysis revealed that chlorophyll-a had an important effect on tintinnid abundance. Tintinnid communities may be used as a potential bio-indicator for assessing the trophic state of the coastal seas and bays.

New Alien Mediterranean Biodiversity Records (August 2022)

In this Collective Article on alien and cryptogenic diversity in the Mediterranean Sea we report a total of 19 species belonging to nine Phyla and coming from nine countries. Several of these records concern fish species, and of particular interest are the first records of: Terapon puta for Italian waters; Pteragopus trispilus from Malta; Plotosus lineatus from Cyprus; and the northernmost Mediterranean record of Lagocephalus sceleratus. The northernmost Mediterranean record was also reported for the sea urchin Diadema setosum. The portunid crab Thalamita poissonii was recorded for the first time in Libya. The copepod Pseudodiaptomus marinus was recorded for the first time in the Marmara Sea. The polychaete Branchiomma luctuosum was recorded for the first time from the Mediterranean coast of France. The alien anemone Diadumene lineata was recorded for the first time from Slovenia. The macroalgae Sargassum furcatum was recorded for the first time from Italy. The new Mediterranean records here reported help tracing abundance and distribution of alien and cryptic species in the Mediterranean Sea

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

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

Machine learning techniques to characterize functional traits of plankton from image data

Plankton imaging systems supported by automated classification and analysis have improved ecologists' ability to observe aquatic ecosystems. Today, we are on the cusp of reliably tracking plankton populations with a suite of lab-based and in situ tools, collecting imaging data at unprecedentedly fine spatial and temporal scales. But these data have potential well beyond examining the abundances of different taxa; the individual images themselves contain a wealth of information on functional traits. Here, we outline traits that could be measured from image data, suggest machine learning and computer vision approaches to extract functional trait information from the images, and discuss promising avenues for novel studies. The approaches we discuss are data agnostic and are broadly applicable to imagery of other aquatic or terrestrial organisms

Preliminary Results on the Feeding and Gut Content of Flaccisagitta enflata in Coastal Areas of Iskenderun Bay (Northeastern Mediterranean Sea)

WOS: 000457128500017In this study, it was aimed to characterize the feeding and diet composition of the most common pelagic chaetognath Flaccisagitta enflata. Zooplankton samples were collected using a WP-2 zooplankton net (200 mu m) at three stations in the Iskenderun Bay in October 2016, December 2016 and March 2017. F. enflata was the most abundant chaetognath in all samples and its proportion varied from 42 to 94%. Younger stages (I and II) dominated the population of F. enflata. In total, 1663 specimens were examined, but only 185 contained prey in their guts. The total food-containing ratio and the number of prey items for this chaetognath species were 11% and 0.1, respectively. These values varied for different maturity stages. Most food items were unidentified due to digestion. Copepods were the main food resource (36.8%) for the species. Cannibalism was also observed. This study is the first to describe F. enflata feeding behaviour in the coastal area of Iskenderun Bay. The preliminary results show that the feeding ratios were within the ranges reported for other regions in the eastern Mediterranean Sea.Cukurova University for Scientific Research Projects [FBA-2016-7080]The present work was supported by the Cukurova University for Scientific Research Projects (FBA-2016-7080). I would like to thank Dr. Sinan Mavruk, Gurkan Akbulut and Haluk Yilmaz for their help during sampling

Seasonal distribution of coastal mesozooplankton community in relation to the environmental factors in Iskenderun Bay (north-east Levantine, Mediterranean Sea)

WOS: 000321510200003Mesozooplankton was studied during 2008 in coastal waters of the Iskenderun Bay in order to determine seasonal changes in abundance, biomass, community structure and their relationship with environmental factors. Samples were collected seasonally at five stations using WP-2 net of 200 m mesh size by vertical hauls. A total of 23 planktonic groups including 30 copepod species, 4 cladocerans and 4 chaetognaths were identified. Copepods were the most important group during the whole period of survey. Penilia avirostris was found to be dominant in spring, while Paracalanus parvus in summer and winter, and Acrocalanus gibber in autumn. Mesozooplankton abundance varied from 438 ind m(-3) (autumn) to 7163 ind m(-3) (spring), while biomass varied between 2.2 mg m(-3) (summer) and 52.9 mg m(-3) (autumn). Differences in abundance and biomass between seasons were statistically significant (P < 0.01). Clear seasonal distribution patterns were observed in the area. Two peaks in abundance were defined: a major peak in spring and a second minor one in autumn. It seems that the trophic element was the main factor affecting the density distribution of zooplankton populations, whereas species distributions were more affected by hydrographical parameters, namely: seawater temperature and salinity

Mesozooplankton composition and distribution in Izmir Bay, Aegean Sea: With special emphasis on copepods

Mesozooplankton are a diverse group of heterotrophic organisms and an important component of the food web in transferring energy to higher trophic levels. Studies on mesozooplankton composition and distribution in Izmir Bay, Aegean Sea, are scarce and they included mostly the data from early 2000s. The present study provides updated information on the status of this important component of the bay. Mesozooplankton composition and distribution were studied in June and November 2017, February and April 2018 from eight stations situated along a transit from inner to the outer region in Izmir Bay, Aegean Sea. Samples were collected vertically by using WP2 net with 200 mu m mesh size. The total mesozooplankton abundance varied from 708 ind. m(-3) in June to 42045 ind. m(-3) in April. The high abundance of polychaeta larvae, cirriped nauplii, copepods and appendicularians were observed in the inner region, while the abundance of echinoderm larvae, chaetognaths, siphonophores and pteropods were high in the central and outer regions. The contribution of copepod to the total mesozooplankton abundance was the highest (>= 56 %) in February in all regions. The lowest contributions were in November (32 %) in the inner region and in June in the central (27 %) and the outer (29 %) regions. A total of 38 copepod species were identified during the study period. Acartia clausi successively dominated the copepod community in February and April. Oithona nana was the most abundant oithonid in February and April, while O. davisae in November. O. similis, Paracalanus parvus, Oncaea media group, Temora stylifera and Centropages typicus were abundant in the central and outer regions of the bay. Four new species, Parvocalanus crassirostris, Pseudodiaptomus marinus, Centropages ponticus and Oithona tenuis were detected for the first time in the bay. The reported abundance of C. ponticus, P. crassirostris and P. marinus, together with their spatial and temporal occurrence in the present study, indicate that these species have already settled in Izmir Bay. Results indicate that the mesozooplankton distribution and composition were associated mostly with salinity and depth rather than temperature in group and species level. Substantial changes in the copepod species composition have been observed over decades in Izmir Bay. The number and abundance of smaller and egg-sac carrying non-indigenous species appear to be increasing over time in the bay. (C) 2022 Elsevier B.V. All rights reserved

Feeding strategy and dietary preference shape the microbiome of epipelagic copepods in a warm nutrient‐impoverished ecosystem

Abstract Copepods provide a rich organic microenvironment allowing the settlement and proliferation of microorganisms, forming dynamic microbial hotspots in the oceans. Such symbiotic associations in the plankton were previously hypothesized to be especially developed in warm oligotrophic seas, as they may serve as alternative sources of nutrients in biologically poor waters. Aiming to better understand how copepod microbiomes are shaped in an oligotrophic sea, we characterized microbiota associated with three dominant coastal epipelagic copepod species in the ultra‐oligotrophic Eastern Mediterranean Sea using amplicon sequencing of the 16S rRNA gene. Our results show that copepod‐associated microbial communities were host‐specific rather than determined by seasonal environmental changes. In the filter‐feeding copepod with a tendency to herbivory, Temora stylifera, microbial diversity was low and relatively stable throughout the year. In contrast, omnivorous copepods, the ambush‐feeding Oithona nana, and the mixed‐feeding Centropages ponticus harbored more diverse microbiomes dominated by transient taxa. We suggest that filter‐feeding strategy and narrow food spectrum can limit copepod–microbe interactions, while the ambush and mixed feeding strategies combined with omnivory confer higher microbial diversity. Filter feeders may reduce the recruitment of opportunistic microbes by maintaining high fidelity associations, as indicated by the large number of core taxa in T. stylifera. We underline the importance of the copepod–microbe associations in nutrient‐impoverished ecosystems, based on predicted enrichment of nitrogen metabolism in the core microbiome, mostly during summer when the shallow coastal waters are nitrogen‐depleted