harpacticoid copepod
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2022 ◽  
Author(s):  
A I Azovsky ◽  
Elena S Chertoprud ◽  
Lesya Garlitska

Abstract Harpacticoid copepods of the Chernaya Bay (White Sea) intertidal zone were collected in 45 surveys carried out from spring to autumn over a 25-year period (1996-2020) at three sites that differed in sediment properties. There were no significant long-term trends or seasonal cycles in total abundance. Regarding the species composition, the differences between sites were the most important source of variability over the whole period while the fine-scale (within-habitat) variability was low. Epibenthic species prevailed in fine silty sand, both burrowing and epibenthic species prevailed in medium sand, and interstitial and burrowing species prevailed in coarse sand. A comparison of the data on harpacticoid assemblages from a number of geographically remote loci corroborated the generality of this pattern. In the temporal dimension, the structure of each community was stable until the early 2000s, when the proportion of epibenthic, burrowing and interstitial species changed following changes in sediment properties (increasing siltation at sandy sites and decreasing siltation at the silty site). At each site, there was an increasing long-term trend in diversity (both in total richness and in expected species number). This increase was particularly apparent at sandy sites because of the appearance of epibenthic species. We suggest that sediment composition is the key factor determining the composition of harpacticoid assemblages in space and time. The “ecomorphological profile”, i.e., the proportion of species with different lifestyle and morphological traits, is a useful and informative indicator for describing and typifying these assemblages.


2022 ◽  
Vol 12 (1) ◽  
Author(s):  
Alfonso Prado-Cabrero ◽  
Rafael Herena-Garcia ◽  
John M. Nolan

AbstractAquaculture is looking for substitutes for fishmeal and fish oil to maintain its continued growth. Zooplankton is the most nutritious option, but its controlled mass production has not yet been achieved. In this context, we have developed a monoalgal ‘green water’ closed-loop bioreactor with the microalgae Tetraselmis chui that continuously produced the harpacticoid copepod Tigriopus californicus. During 145 days of operation, the 2.2 m3 bioreactor produced 3.9 kg (wet weight) of Tigriopus with (dry weight) 0.79 ± 0.29% eicosapentaenoic acid (EPA), 0.82 ± 0.26% docosahexaenoic acid (DHA), 1.89 ± 0,60% 3S,3’S-astaxanthin and an essential amino acid index (EAAI) of 97% for juvenile Atlantic salmon. The reactor kept the pH stable over the operation time (pH 8.81 ± 0.40 in the algae phase and pH 8.22 ± 2.96 in the zooplankton phase), while constantly removed nitrate (322.6 mg L−1) and phosphate (20.4 mg L−1) from the water. As a result of the stable pH and nutrient removal, the bioreactor achieved zero effluent discharges. The upscaling of monoalgal, closed-loop ‘green water’ bioreactors could help standardize zooplankton mass production to supply the aquafeeds industry.


ZooKeys ◽  
2021 ◽  
Vol 1074 ◽  
pp. 1-15
Author(s):  
Juan Manuel Fuentes-Reinés ◽  
Eduardo Suarez-Morales ◽  
Marcelo Silva-Briano

A new species of the harpacticoid copepod genus Esola is described from specimens collected in Rodadero Beach, on Gaira Bay, on the Caribbean coast of Colombia. The species, E. wellsisp. nov., is described, illustrated, and com­pared with its congeners. Esola wellsisp. nov. differs from its known congeners in details of the armature of legs 1–4. It most closely resembles E. bulbifera (Norman, 1911) in the armature formula of P1–P5 but differs from the latter in several respects, including the female antennule segmentation (7-segmented in E. bulbifera but distinctly 6-segmented in E. wellsisp. nov.) and in the shape and size of the male P3ENP2 apophysis, among other characters. This is the second species of the genus known from the Caribbean and the second record of Esola in the Northwestern Tropical Atlantic. The genus now contains eight species. A key to the known species of the genus is also included.


2021 ◽  
Vol 8 ◽  
Author(s):  
James Taylor ◽  
Colin Devey ◽  
Morgane Le Saout ◽  
Sven Petersen ◽  
Inmaculada Frutos ◽  
...  

During RV MS Merian expedition MSM75, an international, multidisciplinary team explored the Reykjanes Ridge from June to August 2018. The first area of study, Steinahóll (150–350 m depth), was chosen based on previous seismic data indicating hydrothermal activity. The sampling strategy included ship- and AUV-mounted multibeam surveys, Remotely Operated Vehicle (ROV), Epibenthic Sledge (EBS), and van Veen grab (vV) deployments. Upon returning to Steinahóll during the final days of MSM75, hydrothermal vent sites were discovered using the ROV Phoca (Kiel, GEOMAR). Here we describe and name three new, distinct hydrothermal vent site vulnerable marine ecosystems (VMEs); Hafgufa, Stökkull, Lyngbakr. The hydrothermal vent sites consisted of multiple anhydrite chimneys with large quantities of bacterial mats visible. The largest of the three sites (Hafgufa) was mapped, and reconstructed in 3D. In total 23,310 individual biological specimens were sampled comprising 41 higher taxa. Unique fauna located in the hydrothermally venting areas included two putative new species of harpacticoid copepod (Tisbe sp. nov. and Amphiascus sp. nov.), as well as the sponge Lycopodina cupressiformis (Carter, 1874). Capitellidae Grube, 1862 and Dorvilleidae Chamberlin, 1919 families dominated hydrothermally influenced samples for polychaetes. Around the hydrothermally influenced sites we observed a notable lack of megafauna, with only a few species being present. While we observed hydrothermal associations, the overall species composition is very similar to that seen at other shallow water vent sites in the north of Iceland, such as the Mohns Ridge vent fields, particularly with peracarid crustaceans. We therefore conclude the community overall reflects the usual “background” fauna of Iceland rather than consisting of “vent endemic” communities as is observed in deeper vent systems, with a few opportunistic species capable of utilizing this specialist environment.


Author(s):  
Helen E Walton ◽  
Joshua J Davison ◽  
Joanna Uzyczak ◽  
Christopher Martin ◽  
Paula Milliken ◽  
...  

ABSTRACT Current experimental protocols for the toxicity assessment of oil spill treatment products in the UK have been established since the 1970s. To address health and safety, cost and scientific robustness issues the UK approach for dispersant testing and approval has been reviewed and updated for implementation during 2020. To provide more robust scientific advice for the risk assessments that enable effective decision making on the use of oil remediation products in the event of a spill there has been a focus on methods that already have internationally accepted protocols. Standardisation of dispersant testing will promote more effective cross-institute comparisons of toxicity data and will enable further harmonisation of approaches in the future. It is preferable that environmentally relevant test species are used but, as the scientific literature provides little conclusive evidence of a taxa-specific trend in sensitivity, species selection based on sensitivity alone was not justified. Eight dispersants, commonly stockpiled in the UK, were tested independently and in combination with a representative crude oil (Kuwait). Testing of dispersants in combination with oil has historically provided more variable results so this study has considered the benefits of this versus product only testing. Core test species included the harpacticoid copepod, Tisbe battagliai, and the algae, Skeletonema sp., as both have cost-effective internationally standardised methods, whilst also being environmentally representative and using test species easily cultured under laboratory conditions with no seasonality. Other candidate test species, such as oyster embryos, had limitations in applicability due to seasonal issues. Fish testing was not considered as there was no ethical reasoning for vertebrate testing due to the absence of taxa-specific toxicity. Results showed that, if oil is excluded from the assessment, Skeletonema sp. and Tisbe battagliai, can produce reliable, reproduceable and interpretable results. When running the T. battagliai test, independently on multiple occasions, without oil, dispersant 1, 2 and 3 had EC50 results that were not statistically different. This suggests that product only testing is suitable for ranking products based on toxicological hazard. The redevelopment of the UK guideline to use standardised testing and the selection of appropriate, environmentally relevant test organisms will increase the quality and reliability of data used to underpin the UK oil spill treatment testing and approval scheme. The adoption of this approach will enable an approved list of products for use in UK waters to be maintained. However, the decision for dispersant use in any given scenario will need to be underpinned through expert advice applying a risk assessment approach taking account a range of incident-specific physical and environmental sensitivity information.


Water ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1020
Author(s):  
Claudia Sbrocca ◽  
Marleen De Troch ◽  
Valentina Losi ◽  
Eleonora Grassi ◽  
Maria Balsamo ◽  
...  

In rocky shore systems, sessile macrobenthic assemblages may act as “ecosystem engineers” for many smaller benthic organisms. Thus, the influence of macrobenthic coverage on the diversity and assemblage structure of the harpacticoid copepod fauna was investigated in the rocky shores of a Marine Protect Area (MPA) in the Ligurian Sea (NW, Mediterranean Sea). Two sampling sites were investigated in two seasons at three different depths on both sub-vertical and inclined reefs. A total of 61 species of copepods mainly represented by Miraciidae, Laophontidae, Longipediidae and Thalestridae were found. The complex micro-topography of these substrata provided a wide variety of niches for many species with different lifestyles that suggests the important role of rocky shores to ensure the functioning of coastal ecosystems. The harpacticoid assemblage structure seemed mainly influenced by season and depth. The temporal spread observed is likely one of the underlying mechanisms of niche segregation that allows many species to co-occur in this specific environment along with a subordinate spatial segregation corresponding to the depth gradient. The results seem to support the hypothesis that the different species composition of the “ecosystem engineer” (and consequently its structure changes) are relevant in structuring the copepod assemblages. The comparison with previous data on general meiofauna underlines that higher surrogacy of the taxonomic identification could be used to study rocky shore communities, but the rich diversity that these systems host can only be understood at the lower taxonomic levels. The same holds for future evaluations of impact of environmental changes (including MPA regulations) on meiofaunal assemblages.


Open Biology ◽  
2021 ◽  
Vol 11 (4) ◽  
Author(s):  
Naoki Kabeya ◽  
Masanari Ogino ◽  
Hideki Ushio ◽  
Yutaka Haga ◽  
Shuichi Satoh ◽  
...  

The long-standing paradigm establishing that global production of Omega-3 (n–3) long-chain polyunsaturated fatty acids (LC-PUFA) derived almost exclusively from marine single-cell organisms, was recently challenged by the discovery that multiple invertebrates possess methyl-end (or ω x) desaturases, critical enzymes enabling the biosynthesis of n–3 LC-PUFA. However, the question of whether animals with ω x desaturases have complete n–3 LC-PUFA biosynthetic pathways and hence can contribute to the production of these compounds in marine ecosystems remained unanswered. In the present study, we investigated the complete enzymatic complement involved in the n–3 LC-PUFA biosynthesis in Tigriopus californicus , an intertidal harpacticoid copepod. A total of two ω x desaturases, five front-end desaturases and six fatty acyl elongases were successfully isolated and functionally characterized. The T. californicus ω x desaturases enable the de novo biosynthesis of C 18 PUFA such as linoleic and α-linolenic acids, as well as several n–3 LC-PUFA from n–6 substrates. Functions demonstrated in front-end desaturases and fatty acyl elongases unveiled various routes through which T. californicus can biosynthesize the physiologically important arachidonic and eicosapentaenoic acids. Moreover, T. californicus possess a Δ4 desaturase, enabling the biosynthesis of docosahexaenoic acid via the ‘Δ4 pathway’. In conclusion, harpacticoid copepods such as T. californicus have complete n–3 LC-PUFA biosynthetic pathways and such capacity illustrates major roles of these invertebrates in the provision of essential fatty acids to upper trophic levels.


Polar Biology ◽  
2021 ◽  
Vol 44 (4) ◽  
pp. 653-665
Author(s):  
Martine J. van den Heuvel-Greve ◽  
Anneke M. van den Brink ◽  
Sander T. Glorius ◽  
G. Arjen de Groot ◽  
Ivo Laros ◽  
...  

AbstractNon-indigenous species (NIS) in the Arctic have an increased likelihood of arrival from ship traffic in the region, while the survival potential of the species becomes more likely in a warming environment. Monitoring is essential to detect the rate and magnitude of the establishment of NIS. In this study, a list of 123 potential marine NIS for Svalbard was drafted and the presence of marine NIS in soft sediment of Kongsfjorden in Svalbard was assessed using molecular metabarcoding techniques. For 37 species, including eight potential Arctic NIS, we generated new 18S and/or COI barcode sequences to improve the available online reference databases. In total, 299 species were identified in the sediment samples, including seven potential NIS. Three of these potential NIS have not been reported before in Svalbard: the harpacticoid copepod Euterpina acutifrons, and the ascidians Botrylloides violaceus and Molgula manhattensis. Another novel observation for Svalbard was the polychaete Chone mollis. Additional studies are needed to assess whether the NIS have been established on Svalbard and what their potential impact on the local system may be. Metabarcoding proved to be an effective monitoring tool to detect the presence of new species in Svalbard marine waters. We advise its use to set up a baseline record for the presence of NIS at points of entry, especially harbours. This approach is also valuable for biodiversity monitoring, in particular the detection of small organisms and life stages that are hard to identify using current visual techniques.


2020 ◽  
Vol 652 ◽  
pp. 33-47
Author(s):  
AN Gangur ◽  
DJ Marshall

Most marine invertebrate larvae either feed or rely on reserves provisioned by parents to fuel development, but facultative feeders can do both. Food availability and temperature are key environmental drivers of larval performance, but the effects of larval experience on performance later in life are poorly understood in facultative feeders. In particular, the functional relevance of facultative feeding is unclear. One feature to be tested is whether starved larvae can survive to adulthood and reproduce. We evaluated effects of larval temperature and food abundance on performance in a marine harpacticoid copepod, Tisbe sp. In doing so, we report the first example of facultative feeding across the entire larval stage for a copepod. In a series of experiments, larvae were reared with ad libitum food or with no food, and at 2 different temperatures (20 vs. 24°C). We found that higher temperatures shortened development time, and larvae reared at higher temperature tended to be smaller. Larval food consistently improved early performance (survival, development rate and size) in larvae, while starvation consistently decreased survival, increased development time and decreased size at metamorphosis. Nonetheless, a small proportion (3-9.5%, or 30-42.7% with antibiotics) of larvae survived to metamorphosis, could recover from a foodless larval environment, reach maturity and successfully reproduce. We recommend that future studies of facultative feeding consider the impact of larval environments on adult performance and ability to reproduce.


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