Harpacticoid Copepods Research Articles

Acute and multigenerational effects of short-chain chlorinated paraffins on the harpacticoid copepod Tigriopus japonicus

Although the measurement of short-chain chlorinated paraffins (SCCPs) in aquatic ecosystems has increased, limited information is available on their toxic effects on aquatic animals. To evaluate the harmful effects of SCCPs, we assessed their acute impact on 24-h survival and biochemical parameters, as well as their chronic effects on growth and reproduction over three generations in the harpacticoid copepod Tigriopus japonicus. Dose-dependent increases in mortality were observed, with an LC50 value of 74.6 μg L−1 for 24 h. Acute exposure to the LC10 value for 24 h significantly reduced feeding behavior, accompanied by a notable decrease in acetylcholinesterase enzymatic activity. Simultaneously, the intracellular levels of reactive oxygen species increased, along with elevated malondialdehyde contents. Glutathione level was increased by the LC10 value of SCCPs with the induction of enzymatic activities of antioxidant defense components, including glutathione S-transferase, catalase, superoxide dismutase, glutathione peroxidase, and glutathione reductase. When T. japonicus was continuously exposed to 1/10 of the NOEC and NOEC values for 12 days across three generations (F0–F2), growth retardation was observed in the F2 generation, with delay in the developmental periods from nauplius to adult. Although the total number of nauplii per brood was not significantly altered across generations, a significant delay in the onset of reproduction was observed in the F2 generation. Our findings suggest that even sublethal concentrations of SCCPs can negatively affect the health of copepod populations with consistent exposure.

Temperature dependent sensitivity of the harpacticoid copepod Nitokra spinipes to marine algal toxins

Harmful algal blooms (HABs) – proliferated algae densities, often producing toxins – have increasingly been found in ocean and coastal areas. Recent studies show that rising temperatures contribute to HAB occurrence, but the broader influence of climate change on these outbreaks is less quantified. Of particular concern is the limited research on HAB toxin effects under varying temperatures, especially regarding primary consumers such as copepods, a crucial component of aquatic ecosystems. Therefore, we examined the impact of marine toxins on the harpacticoid copepod Nitokra spinipes, a model organism for marine ecotoxicology, in the context of climate change. We evaluated the toxicity of four purified, commonly occurring algal toxins, at three different temperatures in the laboratory. First, adult females were exposed to a concentration series of toxins at 15, 20, and 25 °C for 48 hours. EC50 values of domoic acid ranged from 8.79 ± 1.93 μg L-1 to 25.97 ± 11.96 μg L-1. Nauplii, aged 48 to 72 hours, were exposed at 18, 20 and 22 °C for the same duration. Less sensitive compared to adults, the EC50 of domoic acid in this case varied from 57.26 ± 6.82 μg L-1 to 97.24 ± 6.45 μg L-1. Both results indicated a temperature-dependent EC50. For the chronic toxicity tests, larval development ratio (LDR), brood size and inter-brood time of domoic acid (DA), yessotoxin (YTX), saxitoxin (STX), and microcystin-LR (MC-LR) were examined at 18, 20 and 22 °C. We observed that with increasing temperatures, LDR increased, whereas brood size significantly decreased as DA, YTX or STX concentrations rose. No interaction between temperature and algal toxins was found but a temperature dependent sensitivity of copepods towards DA, YTX and STX was revealed. Our research provides insights into the effects of long-term exposure to algal toxins on marine copepods and the potential impacts of climate warming.

Effect of Concentration and Frequency of Feeding with Food (Fermented Rice Bran) on Mass Culture of Natural Copepod

Development of natural copepod production using fermented rice bran at different concentrations and feeding frequencies was studied. The experiment followed a factorial design with two factors: rice bran concentration (50, 100, and 150 ppm) and feeding frequency (first feeding only and second feeding on day 4 after the first feeding). The experiment was conducted in 18 plastic buckets of 10-liter capacity for a duration of 30 days. The results showed that copepods responded to the increase and decrease in density in the same direction. The interaction between the two factors (rice bran concentration and feeding frequency) showed a significant influence on the copepod density (p<0.05). The highest copepod densities were observed when using first feeding only at a high rice bran concentration of 150 ppm (Mean±SE) of 6.4±1.4a ind./ ml. For the second feeding on day 4 after the first feeding, copepod densities were lower for all concentrations: (Mean±SE) 2.7±0.4, 2.4±0.3, 2.1±0.5 ind./ ml respectively. The most abundant types of copepods were from the orders Calanoid, Cyclopoid, and Harpacticoid copepod with percentages of 64.9, 23.3, 11.8 ind./ml, and the copepod stages were represented by nauplii, adult, copepodite, the adult with eggs. Their percentages were 38.9±2.0, 37.0±1.7, 23.6±1.4, 0.5±0.2 ind./ml, respectively. It can be concluded that using fermented rice bran at a high concentration of 150 ppm with the approach of first feeding only is sufficient enough to increase the mass culture of natural copepods.

Chronic contamination in the southern Gulf of Mexico coastal zone, as evidenced by meiofauna biological traits

Meiofauna is a good pollution indicator that reflects the ecological status of sediments and their linkages with overlying communities. However, long-term monitoring of this fauna is a developing research activity in most marine ecosystems. This study assessed seasonal spatial and temporal changes in meiofauna composition, abundance, and biological traits in the southern Gulf of Mexico sublittoral zone. We examined two questions: How do the meiofauna attributes vary spatially and seasonally? Which contaminants correlate with the distribution of meiofauna biological traits? We analysed sediment characteristics, metals, hydrocarbons, and meiofauna data collected at shallow coastal sites (<10 m) during eight annual surveys (2005–2020). Organic contamination increased when natural disturbances occurred, mainly in the dry season, decreasing the number of nematode taxa and increasing their abundance. During the eight yearly sampling events, nematodes, harpacticoid copepods, and polychaetes varied according to the sedimentary gradient. Chronic contamination (aromatic compounds, Cr, V, Cd, Cr) covaried with meiofauna biological traits. Our results point out meiofauna taxa (e.g., Anoplostoma, Halalaimus, Monhystera, harpacticoid copepods, saccocirrid polychaetes) as bioindicators of resilient and disturbed sites for terrigenous and transitional sediments, while in carbonate sediments dominated sensitive species. Resilient sites were exposed to the Grijalva-Usumacinta river discharges and the oil industry. Tolerant and opportunistic taxa such as the nematodes Anoplostoma and Xyala were classified as colonisers and non-selective deposit feeders. Conversely, sensitive taxa such as Halalaimus and harpacticoid copepods were semelparous, carnivorous, and persisters.

Deep-Sea Benthic Response to the Deepwater Horizon Oil Spill: Harpacticoid Families as Sentinels of Impact Through Space and Time.

The Deepwater Horizon (DWH) oil spill in the northern Gulf of Mexico, occurred in 2010 at 1525 meters depth, releasing approximately 507 M liters of oil. Research cruises in 2010 and 2011 were conducted to assess the initial and subsequent effects of the oil spill on deep-sea infauna. The spatial-temporal response of the deep-sea meiofaunal harpacticoid community composition to the DWH oil spill was investigated at 34 stations ranging from<1 km to nearly 200 km from the wellhead in 2010 and 2011. The pattern of reduced harpacticoid diversity in impacted zones compared to non-impacted zones in 2010 persisted in 2011. However, an increase in Hill's diversity index (N1) and the family richness across the two years in some of the impacted stations could suggest a first signal of a tentative recovery and an improvement of environmental conditions. The multivariate analysis of harpacticoid family composition revealed the persistence of an impact in 2011 with moderately high values of turnover diversity in the harpacticoid communities through time (37%) and space (38-39%). The consistent presence in all years and stations of long-term tolerant families (e.g., Ameiridae), the sharp decrease of fast-responding opportunistic families (e.g., Tisbidae), and the increase of more sensitive ones (e.g., Ectinosomatidae, Canthocamptidae, Cletopsyllidae, and Laophontidae) lead to the preliminary conclusion that some initial signals of recovery are evident. However, as impacts were still evident in 2011, and because recruitment and succession rates can be extremely slow in the deep sea, full community recovery had not yet occurred one year after the DWH disaster. This study confirmed that harpacticoid copepod family diversity can offer an accurate assessment of oil-spill impacts on deep-sea benthic communities over space and time as well as a better understanding of the recovery mode of the system after an oil spill event.

Cryptic diversity and speciation in an endemic copepod crustacean Harpacticella inopinata within Lake Baikal.

Ancient lakes are hotspots of species diversity, posing challenges and opportunities for exploration of the dynamics of endemic diversification. Lake Baikal in Siberia, the oldest lake in the world, hosts a particularly rich crustacean fauna, including the largest known species flock of harpacticoid copepods with some 70 species. Here, we focused on exploring the diversity and evolution within a single nominal species, Harpacticella inopinata Sars, 1908, using molecular markers (mitochondrial COI, nuclear ITS1 and 28S rRNA) and a set of qualitative and quantitative morphological traits. Five major mitochondrial lineages were recognized, with model-corrected COI distances of 0.20-0.37. A concordant pattern was seen in the nuclear data set, and qualitative morphological traits also distinguish a part of the lineages. All this suggests the presence of several hitherto unrecognized cryptic taxa within the baikalian H. inopinata, with long independent histories. The abundances, distributions and inferred demographic histories were different among taxa. Two taxa, H. inopinata CE and H. inopinata CW, were widespread on the eastern and western coasts, respectively, and were largely allopatric. Patterns in mitochondrial variation, that is, shallow star-like haplotype networks, suggest these taxa have spread through the lake relatively recently. Three other taxa, H. inopinata RE, RW and RW2, instead were rare and had more localized distributions on either coast, but showed deeper intraspecies genealogies, suggesting older regional presence. The rare taxa were often found in sympatry with the others and occasionally introgressed by mtDNA from the common ones. The mitochondrial divergence between and within the H. inopinata lineages is still unexpectedly deep, suggesting an unusually high molecular rate. The recognition of true systematic diversity in the evaluation and management of ecosystems is important in hotspots, as it is everywhere else, while the translation of the diversity into a formal taxonomy remains a challenge.

Impact of Pollution on the Biometry of the Harpacticoid Copepod Euterpina acutifrons from the Oum Er Rbia Estuary (Atlantic Coast, Morocco)

Impact of Pollution on the Biometry of the Harpacticoid Copepod Euterpina acutifrons from the Oum Er Rbia Estuary (Atlantic Coast, Morocco)

Identifikasi Jenis Zooplankton di Sepanjang Perairan Sungai Jangkok Kota Mataram

Zooplankton is animal plankton, which plays a role as primary consumers in aquatic ecosystems and as a link in the aquatic food chain. The Jangkok River is one of the large rivers on Lombok Island. This river flows from the western slopes of Mount Rinjani through the Narmada area of ​​West Lombok Regency to downstream at Ampenan Beach. Many river flows provide functions and benefits for the continuity of life of the surrounding community. This research aims to identify zooplankton in the waters of the Jangkok River, Mataram City. This type of research is exploratory descriptive. Research procedures include taking zooplankton water samples horizontally and vertically. Data collection techniques use observation and documentation techniques. The data analysis technique uses the zooplankton abundance index. The research results show that there are 4 types of Zooplankton consisting of 4 species that have been discovered including Harpacticoid copepod, Parathemisto abyssorum, Cyclops bicuspidatus and Diaptomus sp.

Environmental drivers modelling the mangrove Kinorhyncha community along an urban-to-natural gradient in French Guiana (western Atlantic Ocean)

Meiofaunal communities are dominated by free-living nematodes and harpacticoid copepods. Most of the studies defining the environmental drivers that influence meiofauna focus on these profuse groups. The ‘rare’ meiofaunal organisms (densities &amp;lt;5%) are frequently overlooked, making it difficult to know which abiotic variables influence their populations, or their ecological role in the benthic ecosystems. In this study, we explore the ecological factors that characterize a low human-polluted mangrove in French Guiana (western Atlantic Ocean) along an urban-to-natural gradient, focusing on the ‘rare’ phylum Kinorhyncha. This taxon seems to be mainly influenced by sediment size, being more abundant in silty sediments. The presence of microorganisms also enhances the community, likely due to a higher food availability. Oppositely, some trace metals of both lithogenic and anthropogenic origin, as well as predominance of coarser sediment particles, seem to negatively affect their populations. The importance of including the lesser abundant groups of meiofauna in ecological studies is evident, since it allows to have a better idea of the ecological state of marine benthic environments.

The Meioflume: A New System for Observing the Interstitial Behavior of Meiofauna.

Meiofauna (benthic invertebrates<1 mm in size) facilitate sediment biogeochemical cycling, alter sediment microbial community structure, and serve as an important trophic link between benthic micro- and macrofauna, yet the behaviors that mechanistically link individuals to their ecological effects are largely unknown. Meiofauna are small and sediments are opaque, making observing the in situ activities of these animals challenging. We developed the Meioflume, a small, acrylic flow tunnel filled with grains of cryolite, a transparent sand analog, to simulate the in situ conditions experienced by meiofauna in an observable lab environment. The Meioflume has a working area (28.57 mm×10.16 mm×1 mm) that is small enough to quickly locate fauna and clearly observe behavior but large enough that animals are not tightly confined. When connected to a syringe press, the Meioflume can produce low velocity flows consistently and evenly across the width of its working area while retaining the contents. To demonstrate its functionality in observing the behavior of meiofauna, we placed individual meiofaunal animals (a protodrilid annelid, a harpacticoid copepod, and a platyhelminth flatworm) in Meioflumes and filmed their behavioral response to a sudden initiation of porewater flow. All animals were clearly visible within the flume and could be observed responding to the onset of flow. The design and construction of the Meioflume make it an accessible, affordable tool for researchers. This experimental system could be modified to address many questions in meiofaunal ecology, such as studying behavior in response to chemical cues, allowing us to observe meiofaunal behaviors to better understand their ecological effects.

Complementary description of Peltidiumnayarit (Copepoda, Harpaticoida, Peltidiidae) and a new record at Revillagigedo Archipelago, Mexico.

Four adult females of a rare benthic/epiphytic harpacticoid copepod species of the genus Peltidium Philippi, 1839 were collected from insular zooplankton samples obtained at Revillagigedo National Park, Mexico. They were identified as Peltidiumnayarit Suárez-Morales & Jarquín-González, 2013 with type location (and the single previously known distribution site) at Playa Careyeros (20°46'59.46"N, 105°30'35.48"W), Nayarit, Mexico. We provide a complementary description of this species including new details of antennules, caudal rami, legs 1 and 5, and cuticular ornamentation using scanning electron microscopy observations. Peltidiumnayarit has a dark reddish-pink coloration allegedly mimicking the color of the macroalgae where they live, but specimens collected in the present study were obtained from sea surface zooplankton net tows. The record of Peltidiumnayarit in the Revillagigedo Islands represents the southwestern-most record of the genus in the Americas and the second record for Mexico.

New find of Dactylophrya-stage of parasitic suctorian of genus Tachyblaston Martin, 1909 (Ciliophora, Suctorea) with comments on genus taxonomy.

The article presents the new find of Dactylophrya-stage of rare parasitic suctorian ciliate of genus Tachyblaston on harpacticoid copepod from Mumbai, India. The found specimen was identified as Tachyblaston reversum (Collin, 1909), n. comb. The redescription of T. reversum was provided. The refined diagnoses of genus Tachyblaston and included species, data on distribution of genus representatives, synonymy and comments on genus taxonomy are also presented.

Littoral meiofauna community structure in San Julián bay, Santa Cruz province, Argentina

For the first time, standing stocks and community structure have been reported in San Julián Bay, located in the Santa Cruz province, toward the southern tip of South America, within the sub-Antarctic region. The mean density of the meiofauna found was 6724 individuals/10 cm2, with a high dominance of nematodes (97.69%). Multivariate studies (PERMANOVA) revealed two distinct meiofauna assemblages: one, in an upper littoral salt marsh habitat and other, in a medium to low soft bare sediment. In the middle of the bay —in front of San Julián city— salt marsh habitats had the highest meiofaunal density, while bare sediments (medium-low levels) were the lowest. The mean average in the salt marsh area was 12246 individuals/10 cm2, with nematodes being dominant followed by oligochaetes as the subdominant taxa. The mean average in bare sediments (medium to low levels) was 3962 individuals/10 cm2, with nematodes as dominant and turbellarians, mastigophorans and maxillopodos (harpacticoid copepods) as subdominant taxa. Bare sediments related to Patagonian mussel’s populations presented the lowest meiofauna densities. Diversity showed an opposite trend, with a maximum in medium-low levels and a minimum in salt-marshes habitat. Richness in number of taxa ranged from 8 to 12, with a total number of 18 taxa. Despite dominance of nematodes in meiofauna assemblages is known, maximum density found in San Julián bay is much higher than previously found for estuaries from north and mid-latitudes littoral sandy beaches and in the nearby region of the Straits of Magellan and Beagle Channel and other sub-Antarctic and Antarctic sites. On the other hand, the number of meiofauna taxa (no nematodes) is low, and its community structure differs from what has been reported in previous studies. The meiofauna taxa assemblages provide evidence that, in salt-marsh habitats, they have the highest densities, but the lowest diversity when compared with lower levels. This is likely due to adaptation problems of meiofauna communities to a semi-terrestrial habitat.

Seasonal dynamics of sea-ice protist and meiofauna in the northwestern Barents Sea

The rapid decline of Arctic sea ice makes understanding sympagic (ice-associated) biology a particularly urgent task. Here we studied the poorly known seasonality of sea-ice protist and meiofauna community composition, abundance and biomass in the bottom 30 cm of sea ice in relation to ice properties and ice drift trajectories in the northwestern Barents Sea. We expected low abundances during the polar night and highest values during spring prior to ice melt. Sea ice conditions and Chlorophyll a concentrations varied strongly seasonally, while particulate organic carbon concentrations were fairly stable throughout the seasons. In December to May we sampled growing first-year ice, while in July and August melting older sea ice dominated. Low sea-ice biota abundances in March could be related to the late onset of ice formation and short time period for ice algae and uni- and multicellular grazers to establish themselves. Pennate diatoms, such as Navicula spp. and Nitzschia spp., dominated the bottom ice algal communities and were present during all seasons. Except for May, ciliates, dinoflagellates, particularly of the order Gymnodiales, and small-sized flagellates were co-dominant. Ice meiofauna (here including large ciliates and foraminifers) was comprised mainly of harpacticoid copepods, copepod nauplii, rotifers, large ciliates and occasionally acoels and foraminifers, with dominance of omnivore species throughout the seasons. Large ciliates comprised the most abundant meiofauna taxon at all ice stations and seasons (50–90 %) but did not necessarily dominate the biomass. While ice melt might have released and reduced ice algal biomass in July, meiofauna abundance remained high, indicating different annual cycles of protist versus meiofauna taxa. In May highest Chlorophyll a concentrations (29.4 mg m−2) and protist biomass (107 mg C m−2) occurred, while highest meiofauna abundance was found in August (23.9 × 103 Ind. m−2) and biomass in December (0.6 mg C m−2). The abundant December ice biota community further strengthens the emerging notion of an active biota during the dark Arctic winter. The data demonstrated a strong and partially unexpected seasonality in the Barents Sea ice biota, indicating that changes in ice formation, drift and decay will significantly impact the functioning of the ice-associated ecosystem.

Acute and Chronic Effects of the Antifouling Booster Biocide Diuron on the Harpacticoid Copepod Tigriopus japonicus Revealed through Multi-Biomarker Determination

Diuron, an additive biocide in antifouling paints, is widely employed to curtail the attachment of organisms on submerged surfaces in aquatic structures. Despite the detection of diuron in aquatic ecosystems, information regarding its acute and chronic impacts on aquatic invertebrates, particularly planktonic crustaceans, remains limited. In this study, we analyzed the acute (24 h) and chronic (12 days exposure across three generations) effects of different concentrations of diuron (1/10 of the no observed effect concentration (NOEC), the NOEC, and 1/10 of the lethal concentration 50% (LC50), derived from the 24 h acute toxicity value of 1152 μg L−1) on the harpacticoid copepod Tigriopus japonicus. The acute exposure experiment indicated that the 1/10 LC50 value of diuron significantly reduced the copepod’s feeding rate and acetylcholinesterase activity. In response to the 1/10 LC50 value, the intracellular reactive oxygen species were elevated alongside increased malondialdehyde levels, while the glutathione content was depleted. The enzymatic activities of glutathione S-transferase, catalase, and superoxide dismutase were significantly enhanced by the 1/10 LC50 value, suggesting a proactive role of the antioxidant defense system against oxidative stress. Conversely, the activities of glutathione peroxidase and glutathione reductase enzymes were increased at the NOEC value, while their values were reduced by the 1/10 LC50 value. Chronic exposure to 1/10 NOEC and NOEC values revealed the adverse multigenerational effects of diuron. The second generation exhibited the most sensitivity to diuron, with the NOEC value notably reducing survival rate, body length, nauplius-to-adult development, neonates per brood count, and extending the reproduction period. Taken together, our findings underscore that even sublethal diuron levels can adversely impact copepod populations across generations through intergenerational toxicity.

Nototanoides oliveri, a new sponge-dwelling nototanaid tanaidacean (Crustacea, Tanaidomorpha, Tanaidacea) from eastern Gulf of Mexico, with an illustrated taxonomic key, and the first record of harpacticoid copepods within the marsupium of ovigerous female tanaids.

A new species of tanaidacean, Nototanoides oliveri sp. nov. from the eastern part of the Gulf of Mexico is described and illustrated. The new species appears to be most closely related to the recently described western Atlantic species, N. polytrichus. It can be easily distinguished from that species, as well as the other members of the genus, N. trifurcatus and N. ohtsukai, by a combination of characters, including: (1) female antennular article-3 with up to 11 aesthetascs (2) female maxilliped palp article-2 with multifurcate spiniform seta and (3) male cheliped basis having mid-ventral margin swollen, forming a rounded apophysis/protuberance. In addition, an unknown living harpacticoid copepod is reported for the first time within the marsupium of ovigerous females of Tanaidacea. An illustrated key to the four species comprising the genus Nototanoides is presented.

Beneficial microbes to suppress Vibrio and improve the culture performance of copepod Tigriopus japonicus Mori

The use of beneficial microbes, i.e., probiotics, to reduce pathogens and promote the performance of the target species is an important management strategy in mariculture. This study aimed to investigate the potential of four microbes, Debaryomyces hansenii, Ruegeria mobilis, Lactobacillus plantarum, and Bacillus subtilis, to suppress Vibrio and increase survival, population growth and digestive enzyme activity (protease, lipase, and amylase) in the harpacticoid copepod, Tigriopus japonicus. Copepod, T. japonicus stock culture with an initial mean density of 50 individual/mL (25 adult male and 25 adult female) was distributed into five treatments (i.e., four experimental and a control, each with four replicates; repeated twice) using 20 beakers (100 mL capacity each). The copepods were fed a mixture of the dinoflagellate Alexandrium tamarense and the diatom Phyaeodactylum tricornutum (3 × 104 cells/mL−1). Each microbe's concentration was adjusted at 108 CFU/mL−1 and applied to the culture condition. D. hansenii, L. plantarum, and B. subtilis all improved the copepods' survival and population growth, likely by including a higher lipase activity (P < 0.05). In contrast, using R. mobilis did not improve the copepod's culture performance compared to control. B. subtilis was the most effective in decreasing the copepod's external and internal Vibrio loading. The probiotic concentrations in the copepod decreased within days during starvation, suggesting that routine re-application of the probiotics would be needed to sustain the microbial populations and the benefits they provide. Our results demonstrated that D. hansenii and B. subtilis are promising probiotics for mass copepod culture as live food for mariculture purposes.

Morphological and Genetical Identification of &lt;i&gt;Harpacticella inopinata&lt;/i&gt; Sars (Harpacticoida, Copepoda) from Lake Baikal and the Enisey River

The work presents the results of comparative studies of the morphology and genetics of the Baikal subendemic – the harpacticoid copepod Harpacticella inopinata Sars, 1908. The material was obtained from the southern part of Baikal Lake and the Yenisei River within the of Krasnoyarsk city in 1969, 2017–2022. It is shown that morphological variability within the species appeared most in the structure of the antenna exopodite, the number of pores and sensillas on the integument of thoracic somites. The genetic variation of the studied sample of H. inopinata was described by four clades with a distance between them of 0.26, the genetic distances between individuals within the detected genetic groups did not exceed 0.005. It was determined that H. inopinata from geographically remote habitats (Baikal Lake and Yenisei River) forms a single morphological and genetic group. Analysis of the genetic diversity of H. inopinata confirms the relatively recent Baikal origin of the species in the Yenisei, probably associated with an anthropogenic moving into the river.

Cletocamptus cubaensis n. sp. (Harpacticoida, Canthocamptidae) from Cuba with taxonomic notes on the species

Abstract A new species of harpacticoid copepod, Cletocamptus cubaensis n. sp., from a marine aquarium in Cuba, previously identified with the highly polymorphic Cletocamptus deitersi (Richard, 1897), is described herein. A revision of the Cuban material showed that, despite the morphological similarity to Cletocamptus deitersi, there are significant interspecific differences in several microcharacters that were not taken into account in the previous species determination, such as integumental sensilla and pores, and ornamentation of segments, mouthparts, swimming legs, prosome, and urosome. Additionally, some other differences were observed in the relative length and shape of the apophysis of the endopod of P3 in males, the armature complement of the second segment of endopod P2 in males (with four setae instead of three), the ornamentation and length of the caudal rami in both sexes, and the ornamentation of the anal operculum (with 8 spinules). Similarity to other species is discussed, along with brief comments on the morphological similarities and differences between the new species from Cuba and Cletocamptus nudus Gómez, 2005 recorded from Brazil and Colombia, C. schmidti Mielke, 2000 known from the Galapagos archipelago, and C. samariensis Fuentes-Reinés, Zoppi de Roa &amp; Torres, 2015 from Colombia.

Winter spring assemblage pattern of harpacticoid copepods from lagoon waters of Agatti and Kavaratti, Lakshadweep islands, southeastern Arabian Sea

Winter spring assemblage pattern of harpacticoid copepods from lagoon waters of Agatti and Kavaratti, Lakshadweep islands, southeastern Arabian Sea