Evadne Tergestina Research Articles

Spatial heterogeneity of mesozooplankton along the tropical coastal waters

A survey along the coast of India (~1100 km stretch) between Benaulim (Goa) in the west coast and Thoothukudi (Tamil Nadu) in the east coast was conducted during summer 2014, to evaluate the mesozooplankton community structure. Zooplankton community was dominated by holoplanktonic forms representing 93.7% of the total zooplankton, while meroplanktonic forms constituted 6.3%. Zooplankton was generally dominated by copepods which contributed about 69%. In total, forty-eight species of copepods belonging to eighteen families dominated the zooplankton abundance, with a significant contribution of small-sized copepod genera, viz. Bestiolina, Parvocalanus, Acrocalanus, Corycaeus, Oncaea and Oithona. Total mesozooplankton and copepod density ranged from 80 ind. m−3 to 804 ind. m−3 and 28 ind. m−3 to 570 ind. m−3, respectively. Considerably higher abundance of cladocerans (Penilia avirostris and Evadne tergestina) with a significant contribution to zooplankton biomass (r2 = 0.984, p < 0.01) compared to copepods was recorded along the east coast. The results of RDA analysis revealed that the sea surface temperature (SST), nutrients (SiO4 and NO2), dissolved oxygen (DO) and total suspended matter (TSM) were significant environmental variables (p < 0.05; 999 Monte Carlo permutations) associated with the community structure during pre-monsoon period. Both copepod diversity (H′) and dominance (λ) index were higher along the west coast, suggesting the influence of high nutrient and organic input from riverine influx coupled with complex environmental features. The inverse relationship between chlorophyll-a and copepod diversity (H′: r = −0.488, p < 0.01) substantiated the importance of grazing pressure in these coastal waters. In contrast, a positive relationship between chlorophyll-a and copepod dominance (λ: r = 0.434, p < 0.05) indicated that copepods abstained from grazing on phytoplankton. Further characterization of this variability in community structure along the coastal waters requires long-term monitoring at a lower taxonomic level.

Surface mesozooplankton assemblages in a tropical coastal upwelling ecosystem: Southeastern Arabian Sea

The spatio-temporal variation of mesozooplankton assemblages and the relative environmental variables were assessed in a coastal upwelling system. Remarkable seasonal variations were found in the mesozooplankton community structure and Chl-a concentration due to the seasonal shift in the environmental variables. Copepods were found to be the dominant group during the winter monsoon (WM) and spring inter monsoon (SIM) seasons whereas, cladocerans (Evadne tergestina and Penilia avirostris) were dominant during the summer monsoon (SM) which may be attributed to the availability of preferential food and favorable environmental conditions (viz., temperature and salinity etc.). Multivariate statistical analysis revealed that the distribution and their possible spatio-temporal pattern of dominant copepods (Acrocalanus gibber, Acartia danae, Nanocalanus minor and Oncaea venusta), siphonophores (Chelophyes appendiculata and Diphyes chamissonis) and pelagic tunicates (Doliolida sp.) synchronized with their specific food habits and adaptive mechanism. The present findings emphasize the significance of the trophic relationship between Chl-a concentration and mesozooplankton abundance in the coastal waters of Kochi, southeastern Arabian Sea.

Seasonal and interannual variation in mesozooplankton community structure off Tongyeong, southeastern coast of Korea, from 2011 to 2014

Mesozooplankton community structure and environmental factors were monitored monthly at a fixed station off Tongyeong, southeastern coast of Korea, from 2011 to 2014 to better understand the variability of the mesozooplankton community in relation to changes in the marine environment. Total mesozooplankton density varied from 747 to 8,945 inds. m-3 with peaks in summer. The surface water temperature (r = 0.338, p < 0.05) and chlorophyll-a (Chl-a) concentration (r = 0.505, p < 0.001) were parts of the factors that may have induced the mesozooplankton peaks in summer. Copepods accounted for 71% of total mesozooplankton. Total copepod density, particularly cyclopoid copepods, increased during the study period. Cumulative sum plots and anomalies of the cyclopoid copepod density revealed a change of the cyclopoid density from negative to positive in June 2013. A positive relationship between cyclopoid copepods and the Chl-a concentration (r = 0.327, p < 0.05) appeared to be one of the reasons for the increase in cyclopoids. Dominant mesozooplankton species such as Paracalanus parvus s.l., Oikopleura spp., Evadne tergestina, Cirripedia larvae, Corycaeus affinis, Calanus sinicus, and Oithona similis accounted for 60% of total mesozooplankton density. Based on cluster analysis of the mesozooplankton community by year, the seasonal distinction among groups was different in 2014 compared to other years. P. parvus s.l. and its copepodites contributed most in all groups in all four years. Our results suggest that the high Chl-a concentration since 2013 may have caused the changes in mesozooplankton community structure in the study area.

Variation of phytoplankton and zooplankton communities in a sea area, with the building of an artificial upwelling structure

In this study, we investigated changes in the standing crop, species composition, and ecological index of phytoplankton and zooplankton caused by the installation of an artificial upwelling structure in the sea area. The standing crop of phytoplankton and zooplankton in 2009, when the artificial upwelling structure was completed, increased 50-fold and 2.3-fold, respectively, from 2005 when the artificial upwelling structure was installed. During the investigation period, however, the correlation between the standing crop of zooplankton and the standing crop of phytoplankton did not show significant difference (SPSS, p >0.05). Phytoplankton and zooplankton species showed a 2.47-fold increase in a total of 94 species and a 1.68-fold increase in a total of 27 species, respectively, from 2006 to 2009. During the study period, the dominant species of phytoplankton were Chaetoceros didymus (16.5%), Chaetoceros pseudocrinitus (8.5%), Copelatus anastomosans (7.6%), and Skeletonema costatum (6.0%), and the dominant species of zooplankton were Paracalanus parvus (21.6%), Evadne tergestina (6.6%), Paracalanus aculeatus (6.1%), Lucifer intermedius (5.7%), and Sinocalanus tenellus (5.4%), and copepods accounted for the majority of zooplankton. Phytoplankton species diversity index and richness index increased significantly from 1.68 to 2.45 and from 1.61 to 3.65, respectively, in the period from 2006 to 2009, but dominant species index decreased from 0.55 to 0.40 in the same period. It was known that bigger artificial upwelling structures caused a gradually rising upwelling effect and that in the study area, from 2006 to 2009, the ecosystem was changing to a more stable one where a variety of species habitat gradually.

진해만의 장목항에서 단주기 샘플링에 의한 중형동물플랑크톤 군집의 연변동

The annual variation of mesozooplankton community in the Jangmok harbor of Jinhae Bay was studied in relation to environmental variables. Sampling was carried out weekly from January to December 2009. During the study periods, mesozooplankton community consisted of 44 taxa and the annual mean abundance was 8308 inds. <TEX>$m^{-3}$</TEX>. The maximum abundance was observed to be 50043 inds. <TEX>$m^{-3}$</TEX> in August and the minimum in April with 1013 inds. <TEX>$m^{-3}$</TEX>. Of these, Penilia avirostris, cirripedia larvae, Evadne tergestina, Acartia omorii, Oikopleura s, Paracalanus parvus s. l., Eurytemora pacifica, Podon s, Oithona s, and Acartia steueri were observed as dominant species in Jangmok bay and they also contributed to 79% of total mesozooplankton. According to non-metric multidimensional scaling (nMDS) and cluster analysis based on the mesozooplankton community data from each season, the community was divided into three groups. The first group included appearence species in winter and spring season, which is mainly dominated the copepod such as A. omorii and E. pacifica. The second and third group was composed with observed species in summer and autumn, respectively. Based on the SIMPER (similarity percentages), P. avirostris in summer and cirripedia larvae in autumn were significantly dominated. Our results indicate that although the mesozooplankton abundances in Jangmok harbor fluctuated abruptly, its annual variation was strongly influenced by water temperature.

시화호 중형동물플랑크톤 군집의 시공간적 변동

The purpose of this study was to investigate the temporal and spatial variability of taxonomic groups and major species of the mesozooplankton community in Lake Shihwa, Korea. Monthly collections were carried out at five stations in Lake Shihwa for a period of one year. The mesozooplankton community showed distinct seasonal variability with water temperature and salinity. Major mesozooplankton species in each seasonal community were derived from non-metric MDS and SIMPER as follows: winter community (Acartia hongi and Eurytemora pacifica), spring community (Acartia hudsonica and Polychaeta larvae), summer community (Acartia sinjiensis, Pavocalanus crassirostris, Evadne tergestina and Cirripedia nauplii) and fall community (Paracalanus indicus and Podon leuckarti). The succession of the seasonal species, A. hudsonica and A. sinjiensis, was the most remarkable event during the seasonal changes of the mesozooplankton community. The species response curve of these species fitted with the logistic regression in relation to water temperature and salinity. The curve also correctly represented the characteristics of the occurrence of A. hudsonica and A. sinjiensis in Lake Shihwa.

Analysis on Community Structure of Zooplankton in Zhoushan Fishing Ground and Its Adjacent Area in Summer

Based on the data acquired within the Zhoushan fishing ground and its adjacent area (29&deg;30&prime; &#8722;31&deg;30&prime; N, 121&deg;30&prime; &#8722;124&deg;30&prime; E), species composition, abundance, and species diversity of zooplankton were sampled by plankton net (50 cm mouth-diameter, 145 cm net length, 0.505 mm mesh-aperture) during August 2006. The results identified 93 species (exclude Larvae) from the samples, among which Copepods were the most diverse with 50 species. According to the standard of IRI (the species with IRI above 0.02 were regarded as dominant species in this paper), there were 12 dominant species: Euchaeta concinna, Dolioletta gegenbauri, Sagitta enflata, Sagitta bedoti, Calanus sinicus, Undinula vulgaris, Canthocalanus paupe, Macruran larvae, Diphyes chamissoni, Centropages dorsispinatus, Evadne tergestina, Acartia pacifica. The stations of high abundance were mainly in the southern part and oceanic sea, and low in the northern and near shore waters. Zooplankton in the Zhoushan fishing ground and its adjacent area exhibited high in evenness (0.70), high species number and high diversity indices (4.98). By hierarchical cluster analysis and non-metric multidimensional scaling (MDS) assisted analyzing, zooplankton in Zhoushan fishing ground and its adjacent area could be formed into three assemblages joining at a distance of 17.13%. The biota-environment matching (BIOENV) analysis showed that the abundance of zooplankton was correlated closely not only to salinity, nitrate, silicate, but also to the Cd and Pb.

여름철 장목만의 환경요인과 중형동물플랑크톤 단주기 변동과의 상관성

Daily samples were collected during summer in order to analyse changes in the mesozooplankton community and to identify the major environmental factors that may influence mesozooplankton abundance in Jangmok Bay. A single site in the bay was sampled 47 times from July to September 2003. Mesozooplankton community, hydrographic (watertemperature, salinity, dissolvedoxygen) and biological (chlorophyll-a, ciliates densities, Noctiluca scintillans densities) factors were determined. The mesozooplankton abundance varied remarkably from 954 to <TEX>$14,816\;inds.\;m^{-3}$</TEX>. The six taxa of Evadne tergestina, barnacle nauplii and cypris, Paracalanus parvus s.1., Acartia omorii, Penilia avirostris and Sagitta crassa dominated numerically, contributing 86% of total mesozooplankton abundance. Stepwise multiple linear regression analysis was applied to find correlation between environmental factors and fluctuation in the abundance of dominant species and mesozooplankton. A. omorii was significantly correlated with temperature and N. scintillans densities. E. tergestina was correlated with temperature, salinity, and ciliate densities, whereas P. avirostris was correlated with temperature and dissolved oxygen. Among the environmental factors, mesozooplankton abundance correlated most strongly with N. scintillans densities. Accordingly, N. scintillans may be a key player in controlling the fluctuation of mesozooplankton abundance as a strong competitor for same food resources.

Analysis on Community Structure of Zooplankton in Zhoushan Fishing Ground and Its Adjacent Area in Summer

Based on the data acquired within the Zhoushan fishing ground and its adjacent area (29 degrees 30' - 31 degrees 30' N, 121 degrees 30' - 124 degrees 30' E), species composition, abundance, and species diversity of zooplankton were sampled by plankton net (50 cm mouth-diameter, 145 cm net length, 0.505 mm mesh-aperture) during August 2006. The results identified 93 species (exclude Larvae) from the samples, among which Copepods were the most diverse with 50 species. According to the standard of IRI (the species with IRI above 0.02 were regarded as dominant species in this paper), there were 12 dominant species: Euchaeta concinna, Dolioletta gegenbauri, Sagitta enflata, Sagitta bedoti, Calanus sinicus, Undinula vulgaris, Canthocalanus paupe, Macruran larvae, Diphyes chamissoni, Centropages dorsispinatus, Evadne tergestina, Acartia pacifica. The stations of high abundance were mainly in the southern part and oceanic sea, and low in the northern and near shore waters. Zooplankton in the Zhoushan fishing ground and its adjacent area exhibited high in evenness (0.70), high species number and high diversity indices (4.98). By hierarchical cluster analysis and non-metric multidimensional scaling (MDS) assisted analyzing, zooplankton in Zhoushan fishing ground and its adjacent area could be formed into three assemblages joining at a distance of 17.13%. The biota-environment matching (BIOENV) analysis showed that the abundance of zooplankton was correlated closely not only to salinity, nitrate, silicate, but also to the Cd and Pb.

2006년 하계 가막만의 환경요인 변동에 따른 중형동물플랑크톤 군집의 단기 변동

The short-term variations of the mesozooplankton community structure were investigated in Gamak Bay during summer season, 2006. The study was based on a comprehensive survey constituting from 12 stations on June 19, July 28, August 4, and August 29, respectively. Mean of temperature and chlorophyll <TEX>${\alpha}$</TEX> concentrations in the surface layer were significantly higher than those in bottom layer, and those concentrations were significantly higher in the inner bay than those in the outer bay. A total of 40 taxa including 19 copepods were observed in Gamak Bay during summer season. Mean abundance of total mesozooplankton varied from 1,859 to 26,111 indiv. <TEX>$m^{-3}$</TEX>. The dominant species were Noctiluca scintillans, Penilia avirostris, Evadne tergestina, Paracalanus parvus s. 1., Acartia omorii and Cirriped nauplii and cyprii in Gamak Bay, and they contributed 90% of mean abundance of total mesozooplankton. Noctiluca scintillans was high after the rainfall. Cluster analysis showed that the mesozooplankton community could be divided into 4 distinct groups, indicating rapid change of the community in the short-term of this survey. The relative contribution of each group of the N. scintillans, P. avirostris, E. tergestina, and P. parvus s. 1. showed differences during the phytoplankton bloom period. The mesozooplankton community compositions were highly associated with water temperature, and salinity in physical conditions, and food organisms affect short-term variations in mesozooplankton composition. Interestingly, protozoa N. scintillans, and Cladocera appeared to be one of the key organisms to extinguish the phytoplankton bloom. Therefore, this study suggests that N. scintillans, and Cladocera could be a key player to control the mesozooplankton community structure during summer season, 2006.

Summer mesozooplankton communities in the Turkish Coastal waters of north Aegea Sea

This study was carried out in the northern Aegean Sea during August 2001. Distribution pattern was studied and community analyses of mesozooplankton were made at seven stations in the Turkish coastal waters of northern Aegean Sea. At all stations holoplankton dominated the assemblages (86-99%). Copepods were by far the most abundant taxon contributing 37-92%. The copepod species Acartia clausi, Paracalanus parvus, Mecynocera clausi, Oithona nana and three cladoceran species Penilia avirostris, Evadne tergestina and Evadne spinifera were important components of the zooplankton community in this study.

Zooplankton and Karenia brevis in the Gulf of Mexico

Blooms of the toxic dinoflagellate Karenia brevis are common in the Gulf of Mexico, yet no in situ studies of zooplankton and K. brevis have been conducted there. Zooplankton abundance and taxonomic composition at non-bloom and K. brevis bloom stations within the Ecology of Harmful Algal Blooms (ECOHAB) study area were compared. At non-bloom stations, the most abundant species of zooplankton were Parvocalanus crassirostris, Oithona colcarva, and Paracalanus quasimodo at the 5-m isobath and P. quasimodo, O. colcarva, and Oikopleura dioica at the 25-m isobath. There was considerable overlap in dominance of zooplankton species between the 5 and 25-m isobaths, with nine species contributing to 90% of abundance at both isobaths. At stations within K. brevis blooms however, Acartia tonsa, Centropages velificatus, Temora turbinata, Evadne tergestina, O. colcarva, O. dioica, and P. crassirostris were dominant. Variations in abundance between non-bloom and bloom assemblages were evident, including the reduction in abundance of three key species within K. brevis blooms.

Seasonal Dynamics of Mesozooplankton in Brazilian Coastal Waters

The composition, numerical abundance and seasonal distribution of mesozooplankton, in addition to copepod biomass, were studied in the Sao Sebastiao Channel (SSC) during different seasonal periods and hydrographic regimes. Two stations were sampled every 3 months from January 1996 to July 1997 and also in July 1998 and January 1999. Temporal differences in oceanographic conditions in the SSC were observed; there was clear seasonal variation in the thermohaline structure. Phytoplankton composition, standing-stock and biomass also showed consistent seasonal variation, peaking during summer due to advection of cold and nutrient-rich South Atlantic Central Water (SACW). Sixty-nine mesozooplankton taxa were identified and counted. Mesozooplankton density also increased during summer, ranging from 93 to 12,774 ind m−3. In contrast, a unimodal peak of copepod biomass was recorded during winter and under the influence of the oligotrophic Coastal Water (CW), suggesting that copepod biomass at SSC is driven by resource control. There was no significant evidence of seasonal pattern in overall community composition or evidence of changes due to water mass advection. The mesozooplankton community was continuously dominated by coastal and warm-water species, particularly the copepods Acartia lilljeborgi, Paracalanus aculeatus, P. quasimodo, Parvocalanus crassirostris, Corycaeus giesbrechti and Oithona oswaldocruzi, the cladocerans Penilia avirostris and Evadne tergestina, in addition to the appendicularians Oikopleura longicauda and O. dioica, all of which are perennial species in the SSC. This taxonomic composition may represent an efficient biotic structure for rapid recycling of primary production during periods of SACW influence.

Discriminating zooplankton assemblages in neritic and oceanic waters: A case for the northeast coast of India, Bay of Bengal

Zooplankton species distribution and abundance data at 17 locations in the inshore (10-30 m), shelf (50-200 m) and oceanic (2,500-2,800 m) regions off northeast India (Bay of Bengal) during January 1999-April 2001 revealed 112 taxa represented by 30 divergent groups. Copepods (58 species) dominated (87%) the population numerically. In general zooplankton diversity (Margalef richness d, Shannon-Wiener H', Pielou's evenness J') increased in the direction of the open sea relative to coastal locations with a concomitant decrease both in abundance (ind m(-3)) and biomass (dry mass m(-3)). Based on multivariate analyses, it was possible to distinguish the zooplankton community into different assemblages according to their location (e.g., inshore, shelf, oceanic) and seasonality. While Acrocalanus sp., Oithona sp., Corycaeus danae, Euterpina acutifrons, Paracalanus sp., and Acartia sp. were found characterizing the coastal locations, Oncaea venusta was the discriminating species for shelf waters. In oceanic areas, there was a clear dominance of Labidocera sp., Candacia sp., Euchaeta rimana, Centropages calaninus, Copilia mirabilis and Corycella gibbula. The investigations revealed that changes in zooplankton community structure across water bodies could be associated with differing salinity. During November 1999 (post-monsoon), when salinity in the coastal waters was relatively low (26-28.9 PSU), the zooplankton community consisted of mainly Acrocalanus sp., Salpa, Corycaeus danae, Oikopleura sp., Acartia sp., Evadne tergestina, and Creseis sp. In January 2000 (salinity 32.4-34.1), additionally Corycella gibbula, Labidocera sp., Centropages sp., Microsetella sp., Euterpina acutifrons, Canthocalanus pauper, and Oncaea venusta represented the population discriminating the assemblage from others. In May 2000 (pre-monsoon) when salinity was highest (34.7-35.3), Oithona sp., Paracalanus sp., and Acrocalanus gibber were found important. Chaetognaths formed a distinct group during this period. Results presented during this investigation are considered significant since no previous studies exist for this locale drawing comparisons of the kind made during this study between coastal and oceanic situations.

Diel changes in embryonic maturation in two species of marine cladocerans in Guanabara Bay, Rio de Janeiro, Brazil

Two species of marine cladocerans, Penilia avirostris Dana, 1852 and Evadne tergestina Claus, 1877 were collected in thirteen samples at a fixed station in Guanabara Bay, Rio de Janeiro (30-meter depth) by means of vertical tows with a 200 µm mesh size net at different times from September 12th to 15th, 1995. The parthenogenetic females of Evadne tergestina bore mature embryos (with pigmented eye) only in the samples collected at night, whereas Penilia avirostris at any time of day. This phenomenon was interpreted based on the greater visibility of the Evadne tergestina brood: one of the benefits for embryo maturing during the darkness period would be a decrease of predation on gravid females.

Spatial and temporal variations of Penilia avirostris and Evadne tergestina (Crustacea, Branchiopoda) in a Tropical Bay, Brazil

We analysed monthly samples collected in Guanabara Bay, with a conical net of 200 μm mesh during 1985. The bay was divided into three areas: an outer region (area A), influenced by oceanic waters; an inner region (area C), influenced by fluvial inflow; and a transition region (area B) with intermediate features. Penilia avirostris and Evadne tergestina were observed in the three areas, with greatest densities, however, in the outermost region, which had the highest salinities and lowest temperatures. Penilia avirostris was more abundant in summer (March), a period with the greatest relative densities of nanoplankton. Evadne tergestina was also abundant in summer, but its peak fell in November, a period with a relative increase in microphytoplankton density in the bay. The two species disappeared in winter: Penilia avirostris was absent from May to August, whereas Evadne tergestina disappeared in August and September.

Daily variation of marine cladoceran densities in a tropical bay - Brazil

This contribution presents the daily variation of marine cladoceran densities in Guanabara Bay. The samples were obtained by vertical tows with a 200 μm mesh-size conical net at different times over a 4-day period in September, 1995. Penilia avirostris was the most common species, followed by Evadne tergestina and E. spinifera. These organisms presented higher densities at nightfall. Physical factors like tide and light are responsible for the highest densities. High tide and nightfall time are requested conditions for the P. avirostris and E. tergestina abundance. Temperature and salinity appear to have no relation with cladoceran densities.

Zooplankton assemblages and influence of environmental parameters on them in a Mediterranean coastal area

Temporal dynamics of zooplankton communities and assemblages, as well as the influence of environmental factors on them, were studied in Saronikos Gulf (Aegean Sea, Greece). Different multivariate techniques (hierarchical clustering, multidimensional scaling and correspondence analysis) were applied on a 2 year data set of zooplankton species composition, based on samples collected at five stations of the study area. A clear discrimination of two communities was revealed, the first one in the semi-enclosed polluted northern part (Elefsis Bay) and the second in Saronikos Gulf proper. Within the latter community, five assemblages were distinguished: (i) the coastal winter assemblage characterized by Ctenocalanus vanus, Oithona similis, Clausocalanus pergens and Fritil- laria pellucida; (ii) the psychrophilic assemblage influenced by the open sea and characterized by Oithona plumifera and Clausocalanus jobei; (iii) the spring assemblage characterized by Evadne nordmanni and Cenlropages typicus; (iv) the coastal thermophilic assemblage characterized by Penilia avirostis, Evadne tergestina and Temora stylifera; (v) the thermophilic assemblage influenced by the open sea and characterized by Clausocalanus furcatus. Both zooplankton and environmental data were treated by multiple correspondence analysis which revealed the importance of some environ- mental factors on zooplankton community composition (eutrophication-pollution, temperature, water mass circulation, hydrology and topography).

Cladocera of coastal rivers of western Nigeria

Recent studies indicate that there are at least 100 species of Cladocera in the families Bosminidae, Chydoridae, Daphnidae, Macrothricidae, Moinidae and Sididae in the inland waters of Nigeria. Over 50% of these have been found in net plankton samples from the coastal rivers in addition to Evadne tergestina Claus (Family: Podonidae), and Daphnia barbata Weltner, hitherto unreported in the equatorial lowlands of Africa. In effect, the Cladocera of the coastal rivers and creeks consist of the marine/brackish assemblage made up of Penilia avirostris Dana and Evadne tergestina and the freshwater assemblage made up of all other Cladocera found. Unlike in the more inland water bodies, the freshwater assemblage of the coastal rivers is dominated by the Bosminids Bosmina longirostris (O. F. Muller) and Bosminopsis deitersi Richard. The distribution, seasonality and successional patterns of Cladocera in the coastal water bodies of Western Nigeria is presented.

Diel reproduction and vertical distributions of the marine cladocerans, Evadne tergestina and Penilia avirostris, in contrasting coastal environments

Diel reproduction and vertical distributions of the marine cladocerans, <i>Evadne tergestina</i> and <i>Penilia avirostris</i>, in contrasting coastal environments