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Zoo-holoplankton dynamic between the sites are useful to knowledge with the regard to the characteristic of the areas and in relative to the community structure of zoo-holoplankton.The research conducted in the surrounding waters of Kamal village, the western part of Seram Island, Maluku Province. Zoo-holoplankton organisms collected from six-fixed Research stations consisted of different characteristics, namely stations 1 and 2 are Fish Aggregation Device placement areas, station 3 is the area for setting the lift nets, stations 4 and 6 are in front of the river mouth and station 5 is in the coral reef area. Sampling done every two weeks by using zooplankton net (diameter of 45 cm) sled with a 200 µm meshed. The result showed that the composition of zoo-holoplankton consisted of 37 genera from 8 phylum, 9 classes, and 28 families. There were about 9 genera ( Calanus sp, Calocalanus sp, Acartia sp, Centropages sp, Oithona sp, Onceae sp, Corycaeus sp and Copilia sp), which found in all stations and periods. While some genera are only present at certain stations or periods ( Eucalanus sp, Labidocera sp, Sapphirina sp, and Evadne sp). The abundance of zoo-holoplankton peaked at station 5 (16,332 ind/m −3 ) in the third period, while the lowest was at station 1 (809 ind/m −3 ) in the second period. Similarities indices was high between station 1 and 2 during the whole period (91%, 82% and 78%) and was low between station 1 and 6 (In the first period) and station 3 and 5. We noticed that differences characteristic of sampling areas leading to the abundance and the genera numbers of zoo-holoplankton. .

Our knowledge of the diet of wild octopus paralarvae, Octopus vulgaris, is restricted to the first 2 weeks of its planktonic phase when they are selective hunters found near the coastline. These small paralarvae, bearing only three suckers per arm, are transported by oceanic currents from the coast towards offshore waters, where they complete the planktonic phase over 2 months. Here, we have investigated the trophic ecology of O. vulgaris paralarvae in two contrasting upwelling sub-regions of the Iberian Canary current (ICC) eastern boundary upwelling system and have evaluated dietary change as paralarvae develop (inferred by counting the number of suckers per arm, ranging from three to 15) along the coastal-oceanic gradient during their planktonic phase. Using high-throughput amplicon sequencing, we have characterised the diet of 100 paralarvae collected along the Northwest Iberian Peninsula (n = 65, three to five suckers per arm) and off the west coast of Morocco (n = 35, three to 15 suckers per arm), identifying up to 87 different prey species. The diet of paralarvae varied along the ICC, with crabs (53.4%), siphonophores (12.2%), copepods (12.3%), cnidarians (8.4%) and pteropods (3.7%) accounting for 90% of the variability detected off NW Iberian Peninsula, whereas off W Morocco, crabs (46.2%), copepods (23.1%), cnidarians (12.9%), krill (9.3%) and fishes (4.2%) explained 95.6% of the variability observed using frequency of observance (FOO%) data. Ontogenetic changes in the diet based on groups of paralarvae with similar numbers per arm were evidenced by the decreasing contribution of coastal meroplankton and an increase in oceanic holoplankton, including siphonophores, copepods, pteropods and krill. Trophic niche breadth values ranged from 0.06 to 0.67, with averaged values ranging from 0.23 to 0.33 (generalist = 1 and specialist = 0), suggesting that O. vulgaris paralarvae are selective predators through their ontogenetic transition between coastal and oceanic environments.

The zooplankton of five estuaries of the Basque coast (southeast Bay of Biscay) was surveyed in summer 2019 to check the intraregional spread of exotic species and analyse the cross-estuary differences in brackish and neritic communities related to the arrival of exotic species and the summertime geographic gradient of water temperature. Results revealed that all the studied estuaries have been colonized by Oithona davisae but not by Acartia tonsa and Pseudodiaptomus marinus. Environmental constraints due to estuarine hydrological features partly explained such differences, and the role of secondary spread opportunities remained less clear. Cross-estuary differences in the brackish community mainly reflected changes in the dominance of the native species Acartia bifilosa relative to different exotic copepod species. The neritic holoplankton differed in the contribution of thermophilic species in agreement with the thermal west–east increase of surface water temperature in the inner Bay of Biscay in summer. The detection of large numbers of larvae of the exotic crab Rhithropanopeus harrisii only in one of the estuaries highlighted the role of exotic benthic species in enhancing intraregional differences in estuarine meroplankton. Differences in the dominance of neritic or brackish species as a function of salinity and distance from coastline were also explored.

Integrated use of molecular and morphological methods reveals unexpected diversity in the cosmopolitan siphonophore genus Nanomia. Species delimitation analyses based on COI and 16S sequences suggest up to three distinct lineages in addition to the previously accepted Nanomia bijuga (Delle Chiaje, 1844) and N. cara A. Agassiz, 1865. Here, we describe the North Pacific Nanomia septata sp. n., previously confused with both N. cara and N. bijuga , and provide improved morphological characters for the identification of these three Nanomia species. Phylogenetic analyses suggest two additional, hitherto undescribed clades from Japanese and Chinese waters, respectively, but the lack of morphological material prevents describing these putative species. The geographic distribution of molecularly and/or morphologically verified observations confirm a warm circumglobal distribution for N. bijuga and a boreal North Atlantic distribution for N. cara. Interestingly, four distinct lineages occur in the North Pacific, sometimes in close proximity. These contrasting patterns of distribution raise questions about pelagic speciation processes. Nanomia septata sp. n.: urn:lsid:zoobank.org:act:DAF15EA3-AFEA-4AE8-984F-BDFBCFE7E514 urn:lsid:zoobank.org:pub:478049FC-F672-4D34-ABAE-CF4345EC64D7

Bahía de Los Ángeles (BLA) is located on the peninsular coast of the Gulf of California, near to the midriff islands. It is a greatly diverse ecosystem and a marine protected area due to its importance for whale sharks, turtles, and reef fishes. The bay also supports commercial fisheries that require ecological information for the integrated management of resources. Zooplankton studies are required as is an essential link in the trophic webs. There are few zooplankton studies in BLA focused mainly on the major taxa and species of copepods and cladocerans. Only one study addressed the seasonal variation in zooplankton but with gaps in the sampling. Here, we report the monthly changes in the zooplankton abundance and the composition of the major groups and cladoceran species. Eighty-one samples were collected between September 2017 and January 2019. The holoplankton taxa identified numbered 17, which accounts for 93% of the mean abundance (range 71–100%), with copepods and cladocerans being dominant. The meroplankton consisted of 15 taxa with a greater presence during the warm months (summer–autumn), dominated by the larval stages of bivalves, gastropods, and barnacles. In contrast, many copepod nauplii were found in January associated with low temperatures. Only cladacerans were identified to the species level. They showed strong seasonal fluctuations, reaching a third of the total zooplankton from spring to autumn, with Penilia avirostris being the most abundant species. These results are compared with other temperate and tropical coastal locations of the eastern Pacific.

The taxonomic composition and dynamics of the abundance of holoplankton and meroplankton were studied in the estuary of the seaport Temryuk and in Temryuk Bay (background) in autumn 2018. The impact of the trading port and the Kuban River on the state of holoplankton and meroplankton was assessed. The abundance of holo- and meroplankton in the more desalinated and polluted estuary of the port, which borders the Kuban River, was 1.5–3 times lower than in the Temryuk Bay. In the composition of the copepods Oithona davisae and Acartia tonsa , up to half of non-viable individuals were found in the port estuary. In early autumn, the holoplankton was dominated by Oithona davisa and freshwater cyclopoid copepods; in Temryuk Bay, O. davisae prevailed; in meroplankton, larvae of mollusks wee ubiquitous. At the end of autumn, freshwater cyclopoid copepods and larvae of cirripede barnacles Amphibalanus improvisus were abundant in the port estuary; in the bay, along with O. davisae , brackish-water copepods Еurytemora affinnis , larvae of cirripede barnacles A.improvisus were abundant. The basis of the pool of merorplankton was species tolerant to water eutrophication and sulfide contamination of bottom sediments ( A. improvisus , Bittium reticulatum and Bivalvia).

The meroplanktonic larvae of benthic organisms are an important seasonal component of the zooplankton in temperate coastal waters. The larvae of the reef-building polychaete Lanice conchilega contribute up to 15% of the summer zooplankton biomass in the North Sea. Despite their importance for reef maintenance (which positively affects the benthic community), little is known about the trophic ecology of this meroplanktonic larva. Qualitative and quantitative estimates of carbon (C) transfer between trophic levels and of fatty acid (FA)-specific assimilation, biosynthesis, and bioconversion can be obtained by compound-specific stable isotope analysis of FA. The present work tested the hypothesis that the concept of fatty acid trophic markers (FATM), widely used for studies on holoplankton with intermediate to high lipid contents, is also applicable to lipid-poor organisms such as meroplanktonic larvae. The incorporation of isotopically-enriched dietary C by L. conchilega larvae was traced, and lipid assimilation did not follow FA-specific relative availabilities in the diet. Furthermore, FAs that were unavailable in the diet, such as 22:5(n-3), were recorded in L. conchilega, suggesting their bioconversion by the larvae. The results indicate that L. conchilega larvae preferentially assimilate certain FAs and regulate their FA composition (lipid homeostasis) independently of that of their diet. Their quasi-homeostatic response to dietary FA availability could imply that the concept of FATM has limited application in lipid-poor organisms such as L. conchilega larvae.

Nutrients contents, dissolved oxygen, numerical density, abundance of phytoplankton, holoplankton and meroplankton were obtained in the harbour of Novorossiysk Bay in the autumn season. At the beginning of the autumn 2015, the optimal water temperature in the upper layer of water and the absence of zooplanktonophagous (ctenophore predators) led to the intensive development of plankton communities. The phytoplankton was represented mainly by diatoms algae and zooplankton – by cladoceran, copepods and larvae invertebrates. However, at the beginning of autumn no meaningful relationship between plant and animal components, contents of nutrients and phytoplankton can be found. The zooplankton contained metazoan organisms with a wide range of nutrition including detritophagous. During the autumn season, the phytoplankton community began to transit at the mixotrophic-heterotrophic phase of the annual cycle of development. Probably in the Novorossiysk harbor, the detritus is the most important component in the biotic cycle of matter and energy.

The mesozooplankton community at the north-western Iberian shelf break was studied among adjacent oceanographic regimes (including upwelling, stratification and anticyclonic eddies) during 17 days in autumn 2009. Zooplankton sampling locations were determined in situ, after identifying the oceanographic regimes from CTD profiles performed over the continental shelf and upper slope. Zooplankton samples were sorted indentifying taxonomically the main zooplankton groups, from phylum to subclass. Copepods were the most abundant group (ind m⁻³) in all stations, followed by appendicularians, doliolids and siphonophores. The mesozooplankton community was significantly different amongst oceanographic conditions. Meroplankton abundance was higher in upwelling stations; particularly lamellibranchia, polychaeta and bryozoan larvae abundance, and decreased from early to late upwelling conditions. Medusae and chaetognata were found exclusively under the latter oceanographic regime. However, dissimilarity between the oceanographic conditions was mostly based on the varying contribution of the four most common groups.

Owing to their great diversity and abundance, ammonites and belemnites represented key elements in Mesozoic food webs. Because of their extreme ontogenetic size increase by up to three orders of magnitude, their position in the food webs likely changed during ontogeny. Here, we reconstruct the number of eggs laid by large adult females of these cephalopods and discuss developmental shifts in their ecologic roles. Based on similarities in conch morphology, size, habitat and abundance, we suggest that similar niches occupied in the Cretaceous by juvenile ammonites and belemnites were vacated during the extinction and later partially filled by holoplanktonic gastropods. As primary consumers, these extinct cephalopod groups were important constituents of the plankton and a principal food source for planktivorous organisms. As victims or, respectively, profiteers of this case of ecological replacement, filter feeding chondrichthyans and cetaceans likely filled the niches formerly occupied by large pachycormid fishes during the Jurassic and Cretaceous.