Copepods

"Marine copepods are a potential source of live feed for marine fish larviculture. However, the technology to culture marine copepods economically and at high enough yields is still being developed. This research investigated the effects of container size and configuration, as well as the effects of live versus formulated feed on the overall population yield and population growth rate of short-term high density batch cultures of a marine harpacticoid copepod."

Background

Iceland has high availability of freshwater, and it is rich in brackish and coastal aquatic bodies. However, knowledge on rotifers and meiobenthic and planktonic crustaceans inhabiting these habitats is lacking, and the inland aquatic fauna in Iceland is relatively understudied in comparison with the fauna of adjacent marine ecosystems. The majority of past research focused on larger lakes with the exception of one study on rotifers from the 1950s (Bartoš 1951) and two more recent studies on crustacean fauna of shallow freshwater bodies (Novichkova et al. 2014, Scher et al. 2000). Data are particularly scarce for the south-western part of the country.

New information

We studied the composition of selected invertebrate taxa in various aquatic (marine, brackish and freshwater) habitats from South-western Iceland with a focus on Rotifera, Cladocera and Copepoda. Samples were collected from 12 localities, including marine interstitial, freshwater temporary shallow pools, swamps, wet mosses, springs, and lakes (both brackish and freshwater). We found 39 taxa in total. Rotifera dominated the sampled water bodies, followed by Copepoda and Cladocera. Three of the recorded taxa are new for Iceland, of which two are rotifers [Trichocerca cf. mucosa (Stokes, 1896) and T. vernalis (Hauer, 1936)], and one is a marine copepod (Cyclopina gracilis Claus, 1862). For some of the sampled localities (Sikið and Leirvogsvatn Lakes, and some of the smaller habitats) we present the first data on their microinvertebrate fauna.

A. aegypti, the primary carrier for dengue viruses that cause dengue fever and are widespread over large areas of the tropics and subtropics. The copepod, Acanthocyclops vernalis was collected from a pond located in Hail, a city in northwestern Saudi Arabia. A. aegypti colonies established from Laboratory of Public Health Pests, Jeddah Municipality, Jeddah, Saudi Arabia. In the laboratory, the predatory capacity of copepod predator A. vernalis tested on first and second instars of Aedes aegypti. A single adult female of A. vernalis was tested against 50 larvae of A. aegypti in case the presence and absence of an alternative food. Several doses of A. vernalis (10, 15, 20 and 25 adults) against 100 larvae of mosquito were tested also in case the presence and absence of an alternative food under laboratory conditions.

New examples of Bathonian (Middle Jurassic) parasitic exocysts on acrosaleniid echinoid tests are recorded from
northern France. These exocysts can be attributed to the life activity of copepod crustaceans and are considered
to have been formed as a result of copepod larval settlement in these echinoids by way of the gonopores. Sexual
dimorphism is recognised in copepod-infested Acrosalenia spinosa L. Agassiz, 1840, on the basis of size and
position of gonopores, those in females being larger and wider apart, those in males smaller and situated subcentrally.
The previous stratigraphic range of copepod cysts of this type (i.e., Middle Oxfordian to Middle Kimmeridgian)
can now be extended down to the base of the Bathonian (convergens Subzone).

and the Palk Bay (PB) — two least studied marine environments located between India and Sri Lanka. The
study is based on the results obtained from a field sampling exercise carried out in the GoM and the PB in
March 2010 (Spring Intermonsoon — SIM), September 2010 (Southwest Monsoon — SWM) and January
2011 (Northeast Monsoon — NEM). Based on multivariate analysis of major environmental parameters during
different seasons, it was possible to clearly segregate the GoM and the PB into separate clusters, except
during the SWM. This segregation of the GoM and the PB was closely linked with the seasonally reversing
ocean currents in the region, as evident from the MIKE 21 flow model results. During the period of relatively
low phytoplankton biomass (b23 mg C m−3), the organic carbon contribution of the microbial loop was significantly
high — both in the GoM and the PB. During the SIM, the carbon biomass available in the plankton
food web was significantly higher in the PB (av. 122.8±47.60 mg C m−3) than in the GoM (av. 81.89±
35.50 mg C m−3). This was due to a strong microbial loop in the former region. In the GoM, phytoplankton
contributed a considerable portion (>50%) of the carbon biomass during the SWM and the NEM, whereas,
microbial loop contributed significantly (80%) during the SIM. The microbial loop was predominant in the
PB throughout the study period, being as high as 83% of the total plankton biomass during the SIM. As
compared to the PB, the mesozooplankton biomass was higher in the GoM during the SWM and the NEM
and lower during the SIM. The relatively high mesozooplankton stock in the PB during the SIM was closely
linked with a strong microbial loop, which contributed the major share (av. 101.6±24.3 mg C m−3) of the
total organic carbon available in the food web (av. 126.6±24.3 mg C m−3). However, when microbial loop
contributed >65% of the total organic carbon available in the food web, the trophic efficiency was found to
be low (~3%), which can be attributed to the wide dispersal of organic carbon in the microbial loop. Importantly,
during the NEM, when the copepod Paracalanus parvus was predominant in the PB, the trophic efficiency
of the microbial loop dominant food web increased by more than a fold (7.2%). The study provides
evidences for the first time from the field that exceptionally high abundance of efficient microzooplanktonconsuming
zooplankton can significantly increase the trophic efficiency of the microbial loop dominant
plankton food web.

Meiobenthos in Bidong Archipelago in coastal water of the South China Sea is hypothesised to have a certain trend of distribution particularly in the island ecosystem where it is usually having different type of sea bottom. Nonetheless, since it is located in a tropical area, the trend at the sub-tidal could be less obvious due to absent of clear season. Meiobenthic sampling was carried out in Karah Island, an island in Bidong Archipelago, from the intertidal, towards the sub-tidal zone covering the coral and non-coral area to see the trend in the density and composition. A transparent hand core was used to collect benthos samples. Nematoda and harpacticoid copepods dominated the intertidal and sub-tidal zone respectively. Harpacticoid copepods were higher in density in the non-coral sediment than the coral area. This could be due to the high content of silt and clay in the coral area (2.98% of silt and clay). The 2-dimension MDS analysis on the density data indicated the highest degree of scattering and an overlapping condition for those intertidal and sub-tidal samples respectively. ANOSIM result showed that the degree of similarity was lower at the intertidal (70%) than the sub-tidal (reaching 90%) in the first sampling before both became no significant different in the second sampling. It could indicate the stable condition in the subtidal than the intertidal ecosystem. The comparatively low density of meiobenthos could indicate their response towards the environmental condition in the area which will only be confirmed by long term ecological study. ABSTRAK Meiobentos di Kepulauan Bidong di perairan Laut China Selatan mungkin mempunyai corak taburan yang tertentu terutamanya di dalam ekosistem pulau dan terdapat jenis permukaan dasar yang berbeza-beza. Walau bagaimanapun, oleh kerana ia terletak di kawasan tropika, corak di kawasan pasang-surut mungkin kurang jelas berikutan daripada ketiadaan kesan musiman. Pensampelan meiobentos telah dijalankan di Pulau Karah, sebuah pulau di Kepulauan Bidong, dari kawasan antara pasang-surut, menuju zon pasang-surut yang meliputi kawasan karang dan tanpa karang, untuk memerhatikan corak kepadatan dan komposisi. Nematoda dan harpaktikoid copepod mendominasi masing-masing di zon antara pasang-surut dan pasang-surut. Harpaktikoid copepod mempunyai kepadatan yang lebih tinggi di sedimen tanpa karang berbanding zon karang. Ini berkemungkinan disebabkan oleh kandungan liat dan lumpur yang tinggi di dalam kawasan karang (2.98% liat dan lumpur). Analisis 2-dimensi MDS ke atas data kepadatan menunjukkan aras serakan yang paling tinggi berlaku di kawasan antara pasang-surut dan keadaan bertindih berlaku kepada sampel dari kawasan pasang-surut. Keputusan ANOSIM menunjukkan aras keserataan adalah rendah di zon antara pasang-surut (70%) berbanding zon pasang-surut (mencapai 90%) di dalam pensampelan pertama sebelum kedua-dua kawasan menunjukkan tiada persamaan signifikan di dalam pensampelan kedua. Ini menunjukkan keadaan stabil ekosistem pasang-surut berbanding zon antara pasang-surut. Kepadatan meiobentos yang rendah secara bandingan mungkin menunjukkan tindak balas terhadap keadaan persekitaran yang hanya dapat disahkan melalui kajian ekologi jangka panjang di kawasan ini.

The underlying mechanisms that influence micro-plastic ingestion in marine zooplankton remain poorly understood. Here, we investigate how microplastics of a variety of shapes (bead, fiber, and fragment), in combination with the algal-derived infochemicals dimethyl sulfide (DMS) and dimethylsulfoniopropi-onate (DMSP), affect the ingestion rate of microplastics in three species of zooplankton, the copepods Calanus helgolandicus and Acartia tonsa and larvae of the European lobster Homarus gammarus. We show that shape affects microplastic bioavailability to different species of zooplankton, with each species ingesting significantly more of a certain shape: C. helgolandicusfragments (P < 0.05); A. tonsafibers (P < 0.01); H. gammarus larvae beads (P < 0.05). Thus, different feeding strategies between species may affect shape selectivity. Our results also showed significantly increased ingestion rates by C. helgolandicus on all microplastics that were infused with DMS (P < 0.01) and by H. gammarus larvae and A. tonsa on DMS-infused fibers and fragments (P < 0.05). By using a range of more environmentally relevant microplastics, our findings highlight how the feeding strategies of different zooplankton species may influence their susceptibility to microplastic ingestion. Furthermore, our novel study suggests that species reliant on chemosensory cues to locate their prey may be at an increased risk of ingesting aged microplastics in the marine environment.

Penelitian ini bertujuan untuk mengetahui laju pertumbuhan dan panjang tubuh kopepoda Apocyclops sp. yang diberi pakan alami N. oculata, T. chuii dan T. suecica. Mengetahui jenis pakan alami terbaik untuk pertumbuhan Apocyclops sp. Penelitian ini dilakukan pada bulan Februari 2017 dengan rancangan acak lengkap (RAL).Pertumbuhan panjang tubuh copepod pada jenis pakan T. chuii didapatkan nilai pertumbuhan rata-ratanya yakni 385,44 µm, untuk jenis perlakuan jenis pakan T. suecica laju pertumbuhan rata-ratanya yakni 273,22 µm, serta pada pakan alami N. oculata laju pertambahan panjang rata-ratanya adalah 242,28 µm. Dari 3 jenis perlakuan pakan pada kopepoda rata-rata pertumbuhannya adalah 300,31 µm. Pakan terbaik untuk menunjang pertumbuhan panjang copepod dari semua perlakuan pakan yakni pada jenis pakan T. chuii

We investigated changes in the species richness, abundance, and composition of the zooplankton community in response to the formation of a small reservoir in the Caveiras River, southern Brazil. Zooplankton were collected using a motor-pump and a plankton net (68 μm mesh), with 600 L of water filtered per sample. Sampling occurred during the pre-(April, August, and December 2011) and postimpoundment (July and October 2013, and January 2014) phases of the Caveiras River. We identified 86 taxa in this study, and rotifers were the predominant group. The species richness and abundance of the zooplankton increased after the filling of the reservoir. Furthermore, the zooplankton community showed a clear change in the species composition between the phases before and after the formation of the reservoir, with the emergence of typical planktonic species. Changes in the structure of the zooplankton community were related to changes in limnological characteristics due to the impoundment of the river, mainly in the availability of food and in the concentration of nutrients.

Copepods-TR-Ep69
ReleasedSep 01, 2006

Copepods, you think you know them? well in this show im joined by Dr. Adelaide Rhodes, a world recognized expert on Copepods. Adelaide will take us though the in's and out's of copepods and what they mean to out tanks today, and in the future. In this show we discuss - What are copepods - Identifying copepods - What are copepods good for - How to get copepods in your system - Breeding copepods in and out of your tank - And much more

A striking color polymorphism exists in diaptomids inhabiting adjacent alkaline lakes in the Grand Coulee area of Eastern Washington. These highly alkaline lakes were formed following the last Ice Age, when the Columbia River became channelized. Copepods isolated from Soap Lake exhibit higher levels of red pigmentation at all times of the year in comparison to copepods from Lake Lenore. Nutrients, salinity, light and predation pressure have all been proposed to explain the difference in pigmentation between the lakes. Copepods from Lake Lenore cannot be induced to express the bright red coloration of Soap Lake copepods, even though Soap Lake copepods can lose their color in the lab. An alternative hypothesis to explain the difference in coloration between the populations of diaptomid copepods is genetic adaptation to the more stressful environment of Soap Lake. It is possible that copepods from Soap Lake and Lake Lenore represent parapatric groups formed by dispersal from allopatric Pleistocene refugia during the formation of the Grand Coulee. Soap Lake is deeper, saltier and more alkaline than Lake Lenore, and the lakes are not connected. These unique mineral and geological conditions could have led to a genetic divergence in coloration, enhanced by the more extreme alkalinities experienced by Soap Lake diaptomid copepods. Carotenoid biosynthesis might be increased in Soap Lake copepods due to a shared pathway for lipid desaturation utilizing oxidoreductase. The production of carotenoids increases antioxidant activity and allows for lipid storage and utilization in highly alkaline conditions. It is possible that intense red color is a byproduct of basic metabolic functions involving lipid storage and utilization in copepods. The function of carotenoid genes in Soap Lake diaptomids could provide clues as to why so many species of copepods in extreme environments are bright red.