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Astaxanthin is ubiquitous in calanoid copepods in high latitude or altitude regions and is well studied. However, the dynamics of astaxanthin in calanoids at low latitudes are less studied. We collected samples during the ice-free season from Lake Mubanghai, an alpine lake located in a low-latitude and high-altitude region, and analyzed astaxanthin content changes among different developmental stages in Arctodiaptomus walterianus. The total astaxanthin content in A. walterianus varied from 1.66 to 4.49 μg/mg dry weight and was highest in October, the month with the lowest temperature among the three sampling dates. Both free astaxanthin and astaxanthin esters content per biomass and the ratio of free astaxanthin increased from the nauplius to adult stage, and astaxanthin esters dominated in total astaxanthin in all developmental stages. The concentrations of polyunsaturated fatty acids were low in seston but were the main fatty acids in the calanoid. The total fatty acid concentration was positively correlated with the concentrations of total astaxanthin, free astaxanthin and astaxanthin esters in the calanoid. These results suggested that astaxanthin may be beneficial to the accumulation of fatty acids. This strategy may benefit calanoids in adaptation to high mountain environments at low latitudes.

A massive invasion of the Neotropical calanoid copepod Arctodiaptomus dorsalis (Marsh, 1907) has been taking place in the Philippines since at least 1993. This copepod’s fecundity is known to depend on food concentration, increasing temperature appears to have detrimental effects on its hatching success and survivorship, but parameters that are truly predictive of the successful integration and propagation of this species in particular bodies of water have not yet been identified. We conducted a spatial analysis of morphometric features and reproductive capacity, the latter proxied by clutch size (CS), of different populations of A. dorsalis inhabiting 11 tropical lakes in the Philippines. Correlations between either morphometry or CS and selected water quality parameters were investigated based on collections and measurements made from December 2018 to April 2019. Means of morphometric measurements differed significantly (P < 0.001) among the populations of A. dorsalis in all lakes. Total length (TL) of adult males, TL of non-ovigerous adult females, and CS of ovigerous females all showed significant (P < 0.001) inverse correlations with lake depth, accounting for about 30% of the observed variability among lakes (r = –0.55, –0.55, and –0.58, respectively). Shallow lakes, which are more homogenous in terms of nutrient distribution throughout the water column, thus provide a more suitable habitat than deep lakes for A. dorsalis and provides a partial explanation of the widespread occurrence and abundance of the species in the shallower, more eutrophic lakes in the Philippines.

In eastern region of Turkey, copepod fauna of 31 localities was investigated and 23 species were identified from 4 families. Aygır Lake is the richest with 7 species in terms of the number of copepod species, followed by the Kuyucuk Lake and the Akcakale Peninsula with 6 species. No copepods were found at stations 2, 5, 8, 9, 10, 19, 20, 22, 23, 24 for reasons of human settlements, water quality parameters and environmental factors. The Calanoid copepod, Arctodiaptomus (M) toni which was found in two stations (Lavaş Lake and Putka Gölbaşı Lake) is new record for the inland waters of Turkey. Both habitats of the species are similar to each other in terms of altitude and lake structure, and similar to Elburz, where the species was first found., Türkiye'nin doğu bölgesinde, 31 lokalitenin kopepod faunası araştırılmış ve 4 familyadan 23 tür tespit edilmiştir. Aygır Gölü, kopepod türü sayısı bakımından 7 tür ile en zengin olduğu belirlenirken, bunu 6 türle Kuyucuk Gölü ve Akçakale Yarımadası izlemektedir. 2, 5, 8, 9, 10, 19, 20, 22, 23, 24 numaralı istasyonlarda insan yerleşimleri, su kalitesi parametreleri ve çevresel faktörler nedeniyle kopepoda rastlanmamıştır. İki istasyonda (Lavaş Gölü ve Putka Gölbaşı Gölü) bulunan kalanoid kopepod, Arctodiaptomus (M) toni, Türkiye iç sularında yeni kayıttır. Türün her iki habitatı da rakım ve göl yapısı açısından birbirine benzer ve türün ilk bulunduğu Elburz'a da benzerdir.

This work aims to analyze the zoogeographic distribution of Calanoida in Kazakhstan. Kazakhstan belongs to the Palaearctic region, and its territory is ascribed to the European–Siberian and Nagorno–Asian biogeographical subregions. The European–Siberian subregion includes the Volga–Ural, Irtysh, and Turkestan–Aral provinces. The Balkhash province belongs to the Nagorno–Asian subregion. Studies of the Calanoida fauna were carried out between 1997 and 2019. For this purpose, 7250 zooplankton samples were taken in 130 different water bodies. Findings of 26 species of Calanoida have been documented. The richest in species composition (20) is the Calanoida fauna of the Irtysh province. Ten Calanoida species have been recorded in the Volga–Ural province, 8 in the Turkestan–Aral province, 7 in the Balkhash province, and 5 in the Ponto–Caspian region. The distribution of the species richness of the order is determined by a complex of climatic factors, including the density of the hydrographic network, a variety of hydrochemical conditions, and accidental acclimatization of species. Far Eastern species (Sinodiaptomus sarsi, Neutrodiaptomus incongruens, Neodiaptomus schmackeri) entered the inland water bodies of Kazakhstan, most likely through the introduction of non-native fish species. The Black Sea species Acartia tonsa and Calanipeda aquaedulcis were introduced into the Caspian Sea with ballast waters. Three autochthonous species (Limnocalanus macrurus, Eurytemora grimmi, Eurytemora minor), formerly inhabiting the Caspian Sea, can now be considered extinct. Acanthodiaptomus denticornis, Arctodiaptomus (R.) salinus, Phyllodiaptomus blanci, and Eudiaptomus graciloides are widespread in the region. Endemic species (Gigantodiaptomus irtyshensis, Arctodiaptomus naurzumensis) and species are new for Kazakhstan (Diaptomus (Chaetodiaptomus) mirus, Eudiaptomus transylvanicus, Arctodiaptomus dentifer, A. (Rh.) ulomskyi were found in small waterbodies, they are known only from single occurrence sites as well as Eurytemora caspica. The last one was described from the northern part of the Caspian Sea, in the coastal zone. Further research into small water bodies that are poorly studied may expand our knowledge of the diversity of Calanoida in Kazakhstan. Calanoida fauna of Kazakhstan was closest to the fauna of countries with a continental climate and most strongly differed from countries with subtropical and Mediterranean types of climates.

The Mediterranean bioregion is widely recognised as a biodiversity hotspot and its inland waters are among the species richest ecosystems of the northern hemisphere. However, the extent of such biodiversity has not been totally unravelled, especially in the Mediterranean islands. Here we present a first account of the crustaceans inhabiting 21 permanent and temporary ponds in Crete, the largest of the Greek islands and the fifth largest island in the Mediterranean Sea. The ponds, sampled between 2009 and 2018, cover all the island surface even though their number cannot be considered exhaustive to represent the entire non-malacostracan fauna of the island. Nevertheless, 46 taxa were identified and most of them are new records for Crete. Moreover, molecular taxonomy allowed to solve the systematic position of Arctodiaptomus piliger Brehm, 1955 and to synonymize this organism, previously considered endemic of the island, with Arctodiaptomus alpinus (Imhof, 1885). As regard branchiopods, this paper contributes a step ahead to clarify the taxonomic position of the Mediterranean Chirocephalus and Ceriodaphnia species. Finally, a review of all the non-stygobitic species present on the island is reported, including 78 taxa (21 Branchiopoda, 28 Copepoda and 29 Ostracoda). Overall, the achieved results offer new clues to solve the complex biogeographical pattern of the “entomostracan” crustaceans inhabiting the inland waters of the Mediterranean region., SCOPUS: ar.j, info:eu-repo/semantics/published

Zooplankton biodiversity is deemed as a realiable indicator of water quality. For 40 years, the Guatemalan lake Amatitlan has shown signs of eutrophication, with measurable impacts on the local zooplankton diversity. Biotic and abiotic variables were surveyed at four sites of lake Amatitlan (Este Centro, Oeste Centro, Bahia Playa de Oro and Michatoya) in 2016 and 2017. The species richness and abundance of rotifers, cladocerans, and copepods were analyzed. The dynamic composition of zooplankton was studied and the system environmental parameters were analyzed in two seasons (rainy and dry season) for both years. Characteristical values of eutrophied tropical systems were obtained, with high rotifer diversity (11 species) and abundance. At present, the rotifers Brachionus havanaensis (109 ind/L) and Keratella americana (304 ind/L) were the most abundant species in the system. The copepod Mastigodiaptomus amatitlanensis considered as endemic in 1941 is absent nowadays, but we reported the unprecedented occurrence of two exotic copepods (i. e., Thermocyclops crassus, Mesocyclops thermocyclopoides) for lake Amatitan and all Guatemala. The presence of large zooplankton like adults and immature copepods (Arctodiaptomus dorsalis) and cladocerans (Ceriodaphnia sp.), in site “Este Centro”, indicates a relatively healthy community and represents a focal point for the conservation for this lake.

Diaptomid copepods belonging to the genus Arctodiaptomus Kiefer, 1932 were collected in two temporary water bodies in Malta. The morphological identification of the collected specimens proved that they belong to Arctodiaptomus wierzejskii (Richard, 1888) even if a morphological peculiarity pertaining to the morphology of the male right antennule of the Maltese populations was observed and here briefly discussed. This finding constitutes the first record of a calanoid copepod from the inland waters of the Maltese Islands.

Astatic soda pans of the Pannonian Steppe are unique environments with respect to their multiple extreme physical and chemical characteristics (high daily water temperature fluctuation, high turbidity, alkaline pH, salinity, polyhumic organic carbon concentration, hypertrophic state and special ionic composition). However, little is known about the seasonal dynamics of the bacterial communities inhabiting these lakes and the role of environmental factors that have the main impact on their structure. Therefore, two soda pans were sampled monthly between April 2013 and July 2014 to reveal changes in the planktonic community. By late spring in both years, a sudden shift in the community structure was observed, the previous algae-associated bacterial communities had collapsed, resulting the highest ratio of Actinobacteria within the bacterioplankton (89%, with the dominance of acIII-A1 lineage) ever reported in the literature. Before these peaks, an extremely high abundance (> 10,000 individuum l−1) of microcrustaceans (Moina brachiata and Arctodiaptomus spinosus) was observed. OTU-based statistical approaches showed that in addition to algal blooms and water-level fluctuations, zooplankton densities had the strongest effect on the composition of bacterial communities. In these extreme environments, this implies a surprisingly strong, community-shaping top-down role of microcrustacean grazers.

The plankton community of sixteen saline lakes located on Onon-Torey plain (Northeastern Mongolia) during the filling phase and the raising of the water level was investigated in July 2011. Thirty-five taxa of phytoplankton and thirty-one species of zooplankton were found. For phytoplankton, blue-green algae (Merismopedia elegans, Anabaenopsis elenkinii, Arthrospora fusiformis, Spirulina major, Lyngbya sp., Oscillatoria sp.) and green algae (Monoraphidium minutum, Tetrastrum komarekii, Ankyra ocellata, Oocystis sp.) were dominant. For zooplankton, Filinia longiseta, Brachionus plicatilis, B. variabilis, Hexarthra mira (Rotifera), Daphnia magna, Moina brachiata, M. mongolica (Cladocera), Arctodiaptomus bacillifer, Mixodiaptomus incrassatus, Metadiaptomus asiaticus (Copepoda) dominated. Mineralization, active hydrogen ratio, dissolved oxygen and water temperature were the main factors influencing the diversity, structure and distribution of plankton organisms in the steppe lakes during low water level. The RDA analysis for phytoplankton and zooplankton from different lakes was carried out for selected two groups which included lakes and a subset related species. The first group is of oligohaline and mesohaline lakes in which mostly green algae, rotifers and copepods inhabit. The second group is of mesohaline and polyhaline lakes with mainly blue-green algae, some crustaceans and rotifers inhabiting. High abundance and biomass of Spirulina major, Oscillatoria sp. and Brachionus variabilis were observed in lakes with high mineralization, pH and temperature.

Two calanoid species,Arctodiaptomus laticeps(Sars, 1863) andEurytemora velox(Lilljeborg, 1853), are reported from the Danube River basin in Croatia. Our findings present the first record ofA. laticepsandE. veloxat the territory of Croatia. Both species were found in the lowland floodplain area during the spring-summer inundation throughout the years. Their occurrence in the waterbodies studied has not overlapped, and different environmental parameters characterized the periods of occurrence of the individual species. The existence ofE. veloxin this region seems to be permanent, whereas the appearance ofA. laticepsis rather confounding.

The genus Pseudodiaptomus is represented by 19 species in Philippine coastal waters. Of all these species found in the Philippines, P. brehmi Kiefer, 1938 is the only known truly freshwater pseudodiaptomid endemic to this country, which was originally described from Lake Naujan, Mindoro Island. After numerous attempts to find it in its type locality, we concluded that the former is no longer extant in this lake and has now been displaced by the invasive Neotropical calanoid Arctodiaptomus dorsalis (Marsh, 1907). Sampling in Lake Taal, on the nearby island of Luzon, resulted in the surprise discovery of P. brehmi populations coexisting with A. dorsalis. This rediscovery of P. brehmi in Lake Taal and its absence from its type locality, necessitate this report as well as the species’ morphological redescription.

We present an updated checklist of the Diaptomidae of China, based on a literature review and on original field data from all over China during 2012-2016. A total of 19 genera and 56 species have been recorded.Neutrodiaptomushas the highest species richness (10 species), followed byArctodiaptomus(9 species). Only one species each ofEudiaptomus,Mixodiaptomus,Eodiaptomus,Dentodiaptomus,Dolodiaptomus,Allodiaptomus,Karstodiaptomus,MetadiaptomusandParadiaptomuswas found. The taxonomic status of 16 species was revised: one wrongly attributed genus,Argyrodiaptomus, was corrected toSinodiaptomus. First records for China includeArctodiaptomus parvispineusand one new cave-dwelling genus,Karstodiaptomus, is added. One Latin name from Shen & Sung’s book (1979) is corrected. Remarks on nomenclature and taxonomic issues are supplemented with information on the geographical distribution of the various species within China.

The diversity, distribution, and checklist of diaptomid copepods from various freshwater ecosystems throughout Thailand are presented, based on data from our biodiversity projects during 1993–2019 and literature reviews. Thailand has one of the most diversified diaptomid fauna in the world, with 42 species identified from 2150 localities (4962 samples). Mongolodiaptomus has the highest species richness with ten species, followed by Tropodiaptomus with seven species. Among these, eight taxa (Arctodiaptomus sp., Mongolodiaptomus pectinidactylus, Neodiaptomus meggitti, Tropodiaptomus hebereri, T. lanaonus, T. oryzanus, T. ruttneri, and Paradiaptomus greeni) are new to the fauna of Thailand. The rare P. greeni, which predominantly occurs in Africa, is also a new record for Southeast Asia. The most frequently encountered species were Mongolodiaptomus botulifer, Phyllodiaptomus praedictus, M. calcarus, M. dumonti, M. malaindosinensis, Vietodiaptomus blachei, Phyllodiaptomus christineae, Eodiaptomus sanoamuangae, Neodiaptomus yangtsekiangensis, E. draconisignivomi, T. vicinus, and Heliodiaptomus elegans. Twelve species appear to be endemic to Thailand, and eight species occur only in the countries belonging to the lower Mekong River Basin (Thailand, Cambodia, Laos, and Vietnam). The uniqueness of the Thai diaptomids is a high degree of co-occurrence of four to seven species in the same localities. Comments on the taxonomic status of the species recorded are provided. In addition, the taxonomic validity of Mongolodiaptomus malaindosinensis is discussed.

Analiziran je sastav zooplanktona u geološki starom, tektonskom Ohridskom jezeru (Makedonija, jugoistočna Europa). Glavni cilj rada bio je utvrditi sezonske i prostorne značajke funkcionalnih hranidbenih skupina zooplanktona i njihovu povezanost s uvjetima okoliša. Najveća produkcija zooplanktona utvrđena je u metalimniju, u kojem su biomasa fitoplanktona i brojnost zooplanktona postigle najveće vrijednosti. Utvrđeno je 16 pelagičkih vrsta od kojih dvije endemične: Arctodiaptomus steindachneri (Richard, 1897) i Cyclops ochridanus (Kiefer, 1932). Zooplankton pelagijala bio je zastupljen s niskom brojnošću, 25 ± 22 ind. L-1, a najveći udio, 60 %, postigli su veslonošci. Unutar trofičke skupine mikrofaga, prevladavali su tijekom ljeta kolnjaci s vrstom Kellicottica longispina (Kellicott, 1879), a naupliji veslonožaca prevladavali su u proljeće Eudiaptomus gracilis (Sars, 1862) and C. achridanus i jesen C.achridanus. Ova trofička skupina hrani se suspenzijom bakterija i detritusa, te je tijekom istraživanog razdoblja zauzimala afotički hipolimnij. Predatori su uglavnom bili zastupljeni s kopepoditima i odraslim veslonošcima u metalimniju. Na njihove populacije su značajno i pozitivno utjecali: temperatura (r = 0.417, p = 0.001), otopljeni kisik (r = 0.463, p = 0.0001) te najizraženije biomasa fitoplanktona (r = 0.708, p < 0.00001). Ovo istraživanje među prvima razmatra zooplankton Ohridskog jezera kao važnu kariku unutar hranidbene mreže ovog oligotrofnog ekosustava., Zooplankton is studied in the ancient, tectonic, oligomictic and oligotrophic Lake Ohrid (Macedonia, South Eastern Europe). The main aim of this study was to assess the seasonal and spatial patterns of the zooplankton functional feeding guilds in relation to the environmental conditions. Metalimnion of the lake was detected as the most productive environment, where biomass of the phytoplankton and abundance of the zooplankton reached their maxima. Pelagial zooplankton of low abundance (25 ± 22 ind. L-1) consisted of 16 species including two endemic copepods, Arctodiaptomus steindachneri (Richard, 1897) and Cyclops ochridanus (Kiefer, 1932). Copepods obtained remarkable share (60%) in the zooplankton assemblage. Microphagous zooplankton was mainly comprised of the most abundant rotifer Kellicottia longispina (Kellicott, 1879) in summer, and copepod nauplii during the spring Eudiaptomus gracilis (Sars, 1862) and C.ochridanus, and autumn C.ochridanus. Due to their requirements for the bacterio-detritus suspension, this microphagous zooplankton occupied aphotic hypolimnion during the entire study period. Raptorials were typically represented by copepodites and adult copepods in the metalimnion, and were significantly and positively affected by temperature (r = 0.417, p = 0.001), dissolved oxygen (r = 0.463, p = 0.0001) and, particularly, phytoplankton biomass (r = 0.708, p < 0.00001). This is the first study in which the link between the lower and higher trophic levels is investigated in Lake Ohrid.

Lake Rio Cuarto is a meromictic maar lake located in the low plains of northern Costa Rica. Its plankton composition has been studied several times since the decade of 1970. Yet most studies made short term surveys, and at least one study lasted for one year. Here we present data on phytoplankton and zooplankton composition from a four year study of the lake, from 2013 to 2017. Phytoplankton was studied from subsurface samples, preserved in Lugol’s solution and zooplankton from 20 m vertical hawls of a 64 um mesh net, and preserved with formaline and later transferred to 95% etanol. Phytoplankton composition included 54 taxa, most of them from the were Chlorophyta, followed by Cyanobacteria and Bacillariophyta. The most abundant were Synechococcus spp., Aphanocapsa sp. Coenochloris fotii, Chlorella sp. and Discostella stelligera. Total phytoplankton decreased from 2013 to 2017, mainly due to a decrease in Cyanobacteria. Zooplankton comprised 14 taxa, 5 cladocerans, 4 copepods, 1 diptera and 4 rotifers. The most abundant were Keratella cochlearis, Brachionus falcatus, Eubosmina tubicen and Arctodiaptomus dorsalis. There was a substitution of dominant species through time, at first (2013-2014) K. cochlearis and E. tubicen alternated in dominance, and later (2015-2016), A. dorsalis, Diaphanosoma sp. and Ceridaphnia sp. became dominant, with a return of K. cochlearis by 2017. The relationship between both components of the plankton is a complex result of the responses of individual species of both microalgae and zooplankton. However, most zooplankton taxa should be regarded as omnivores, so those relationships are not direct causal effects. The changes that occurred during the time of the study seem to be related to changes in the conditions of the lake, since its thermocline deepened with time and became more transparent. Those changes were not cyclical on an annual basis, but seemed to occur more on a long-term basis, as has been recognized earlier in the literature about tropical lakes.

Arctodiaptomus dorsalis (Marsh, 1907) Materials examined. Philippines: Luzon: Manila: Pasig River (14.5604° N, 121.0659° E), coll. DRA Dela Cruz, GAA Viernes, JF Wong, ESP Dela Paz and ML Lopez, June 2016 (UST-ZRC 0253A–B, USTZRC 0254, USTZRC 0255A–B, and USTZRC 0256A–B, 4 spec.). Short description. The body is generally elongated with a long antennule that generally reaches the tip of the urosome. Male specimen: antennule is geniculated. Right exopodite 2 of P5 leg is relatively large and bears a long, thin, and strongly curved terminal claw on the posteromedian area; and with a short lateral spine protruding near the middle of exopodite 2. Female specimen: antennule is straight. The pair of P5 is symmetrical. All the morphological characteristics concur with the descriptions and illustrations of Dussart and Defaye (2001) and Papa et al. (2012). Ecological distribution. Arctodiaptomus dorsalis is found in lakes and rivers. This species is an invasive copepod hence that can tolerate eutrophic condition (Papa et al. 2012)., Published as part of Dela Paz, Erica Silk P., Lopez, Mark Louie D., David, Christian Irvin Harvey A., Dela Cruz, Dave Ryan A., Viernes, Gian Alfonso A., Wong, Jac Fritgerald & Papa, Rey Donne S., 2018, Freshwater microcrustaceans (Cladocera: Anomopoda and Ctenopoda, Copepoda: Cyclopoida and Calanoida) in the highly urbanized Metropolitan Manila area (Luzon, Philippines), pp. 751-762 in Check List 14 (5) on page 757, DOI: 10.15560/14.5.751, {"references":["Dussart BH, Defaye D (2001) Introduction to the Copepoda. 2 nd edition. Guide to the Identification of the Microinvertebrates of the Continental Waters of the World, No. 16. Backhuys Publishers, Leiden. 344 pp.","Papa RDS, Li H, Tordesillas DT, Han B, Dumont HJ (2012) Massive Invasion of Arctodiaptomus dorsalis (Copepoda, Calanoida, Diaptomidae) in Philippine lakes; a threat to Asian zooplankton biodiversity? Biological Invasions 14 (12): 2471 - 2478. http: // doi. org / 10.1007 / s 10530 - 012 - 0250 - 9"]}

Removal of parasite free-living stages by predators has previously been suggested an important factor controlling parasite transmission in aquatic habitats. Experimental studies of zooplankton predation on macroparasite larvae are, however, scarce. We tested whether trematode cercariae, which are often numerous in shallow waters, are suitable prey for syntopic zooplankters. Feeding rates and survival of freshwater cyclopoids (Megacyclops viridis, Macrocyclops distinctus), calanoids (Arctodiaptomus paulseni), cladocerans (Sida crystallina) and rotifers Asplanchna spp., fed with cercariae of Diplostomum pseudospathaceum, a common fish trematode, were studied. In additional long-term experiments, we studied reproduction of cyclopoids fed with cercariae. All tested zooplankton species consumed cercariae. The highest feeding rates were observed for cyclopoids (33 ± 12 cercariae ind−1 h−1), which actively reproduced (up to one egg clutch day−1) when fed ad libitum with cercariae. Their reproductive characteristics did not change significantly with time, indicating that cercariae supported cyclopoids’ dietary needs. Mortality of rotifers and cladocerans was high (25–28% individuals) when exposed to cercariae in contrast to cyclopoids and calanoids (

Arctodiaptomus dorsalis is a Neotropical freshwater calanoid species that is now widely distributed throughout the Philippines because of its ability to adapt well to eutrophic environments and aquaculture. A previous survey already confirmed the presence of A. dorsalis in three lakes in the Bicol peninsula. The primary goal of this study was to determine the extent of the occurrence of A. dorsalis in Bicol given its ability to displace native calanoid species. Samples were collected from 34 freshwater bodies throughout the Bicol Peninsula spanning the provinces of Camarines Norte, Camarines Sur, Sorsogon and Albay. Our results show that A. dorsalis is now recorded from five freshwater ecosystems in Bicol that are linked either through natural connections, aquaculture, or water system constructions. This includes manmade structures such as Lago del Rey and the Camarines Sur Water Sports Complex, and natural freshwater ecosystems such as Lake Buhi, Lake Danao and the Bicol River. Except for Lake Buhi, the other four sampling sites are new locality records for A. dorsalis. Translocation of fishes and passive dispersal through natural or man-made channels aided the dispersal of A. dorsalis in these areas. Though only 14% of the total sampling sites were positive for A. dorsalis, it occurred in the larger water bodies (natural and manmade lakes and large rivers) in the region including one, Lake Buhi, that previously contained native calanoid species such as Tropodiaptomus vicinus. Our results confirm the absence of Tropodiaptomus vicinus from Lake Buhi and the dominance of A. dorsalis in the pelagic plankton community of freshwater ecosystems. It would seem that A. dorsalis invasions in this area are more successful in inter-connected larger freshwater ecosystems. Keywords—Zooplankton, copepods, non-indigenous zooplankton, biological invasion, tropical lakes *Corresponding Author Email Address: ericrizo_99@yahoo.com Submitted: December 17, 2014 Revised: February 19, 2015 Accepted: February 20, 2015 Published: April 27, 2015 Editor-in-charge: Eduardo A. Padlan ____________________________________________________________________________________________________________ www.philscitech.org ARTICLE International Journal of Philippine Science and Technology, Vol. 01, No. 1, 2015 28

Arctodiaptomus (Haplodiaptomus) parvispineus Kiefer, 1935, is a rare and incompletely described species, hitherto known from Himalayan glacial lakes in India. It is now recorded from ponds in Potatso National Park, Yunnan, China and redescribed herein. This is the first record of A. (H.) parvispineus from China. In addition to the descriptions, the morphological variations in the specimens found are briefly discussed.

Summary 1. The European soda pans of the Carpathian Basin provide important stopover sites for several waterbird species. We studied the effect of different invertebrate food types and other characteristics on the habitat choice and distribution of birds on 82 pans (in Hungary, Austria and Serbia) during spring migration. 2. Only three environmental variables proved to be significant determinants of the waterbird communities: pan density (spatial effect) along with the density of Arctodiaptomus spp. and anostracans (local effect). Variance partitioning of the data revealed that aquatic invertebrate food supply (Arctodiaptomus and anostracans) had a greater effect than pan density on the 10 investigated bird species, suggesting a dominant role of species sorting in structuring the communities. Pied avocets (Recurvirostra avosetta) and northern shovelers (Anas clypeata) differed from the other species in their strong association with densities of anostracans (avocet) and Arctodiaptomus (shoveler). 3. Anostracans and microcrustaceans, especially the most frequent Branchinecta orientalis, Arctodiaptomus spinosus and Arctodiaptomus bacillifer, can be regarded as keystone elements of this soda pan habitat because of their bottom-up role in structuring waterbird assemblages during spring migration.

The composition and temporal abundance patterns of zooplankton community in Lake Prespa pelagic zone were studied throughout an annual cycle (October 2008–September 2009). Eighteen species (10 Rotifera, 5 Cladocera, 2 Copepoda, 1 Mollusca) were evidenced. It includes Arctodiaptomus steindachneri, an endemic calanoid of the Western Balkans. The zooplankton density varied during the investigated period and certain seasonal successions in temporal transpositions of their maximal development were noticed. The total zooplankton density was much higher in spring and summer period. The representatives of subclass Copepoda were dominant during the whole year. The dominant species was A. steindachneri. At the second place (with exception of the winter period) were the Cladocera representatives. The dominant species was Daphnia cucullata. At the third and fourth place were rotifers and larval form of Dreissena polymorpha, respectively. The quantitative presence of the Copepoda representatives was significantly lower in terms of the previous investigations. The Cladocera quantity reached high values during this period, particularly in summer. Such altering in the quantitative ratio between Copepoda and Cladocera in favor of the Cladocera, especially high quantitative presence of D. cucullata, typical for eutrophic lakes, imply of significant changes in zooplankton community and changes of the water quality in Lake Prespa pelagial.

Southern Mexico and Central America have many water bodies of different morphology and water chemistry with an interesting zooplankton fauna, originating from North or South America. A set of 63 samples, taken in 2005 and 2008, from water bodies of the Yucatan Peninsula karst, Belize and Guatemala, were studied for the content of calanoid copepods. Old and recent literature was used to determine animals to species level. Drawings were prepared with a microscope and a camera lucida. A total of 32 samples with totally six species contained calanoid copepods: one estuarine pseudodiaptomid and five freshwater diaptomids. Pseudodiaptomus marshi was found at different salinities. it is confirmed that the commonest diaptomids in the Yucatan Peninsula are Arctodiaptomus dorsalis and Mastigodiaptomus nesus. The former was also recorded from Lake Amatitlan. Mastigodiaptomus nesus is as widespread as A. dorsalis but it is absent from the Lake Peten area in Guatemala. Mastigodiaptomus reidae was found in two shallow habitats, these specimens differ from those from the type locality by having a set of peculiar large spine-like processes on the last thoracic and the urosome segments of the females. Leptodiaptomus siciloides was found only in Lake Ayarza with high salinity. Prionodiaptomus colombiensis occurred in the highlands of Guatemala in Lago de Güija and in the Peten area in Laguna Sacpuy. We contributed with our occurrence records to a better knowledge of the geographic distribution of some calanoid copepods. Morphological findings in some species are of value for taxonomic differentiation between species. El sur de México y América Central tienen varios cuerpos de agua con diferente morfología, composición química y una interesante fauna de zooplancton procedente de América del Norte o del Sur. Un grupo de 63 muestras, fueron tomadas en 2005 y 2008 para conocer la cantidad de copépodos calanoides en los cuerpos de agua del karst Península de Yucatán, Belice y Guatemala. Se utilizó literatura antigua y reciente para la identificación de los especímenes a nivel de especie y se preparon dibujos con un microscopio y una cámara lúcida. En un total de 32 muestras se obtuvieron seis especies de copépodos calanoides: un pseudodiaptomidos estuarino y cinco diaptomidos de agua dulce. Pseudodiaptomus marshi fue encontrado a diferentes salinidades. Además, se confirmó que los diaptomidos más comunes en la Península de Yucatán fueron: Arctodiaptomus dorsalis y Mastigodiaptomus nesus. El primero se registró también en el lago de Amatitlán. Mastigodiaptomus nesus está ampliamente distribuido al igual que A. dorsalis, pero se encuentra ausente en el área del Lago Petén en Guatemala. Mastigodiaptomus reidae fue localizado en dos hábitats poco profundos, éstos especímenes difieren de los tipos de la localidad, por tener un grupo de espinas de gran tamaño en la última parte de la caja toráxica y los segmentos del urosoma de las hembras. Leptodiaptomus siciloides se encontró sólo en el Lago Ayarza, el cual contiene alta salinidad. Prionodiaptomus colombiensis se localizó en las tierras altas de Guatemala en el Lago de Güija y en la zona del Petén en Laguna Sacpuy. Se contribuye con registros de presencia de especies para un mejor conocimiento de la distribución geográfica de algunos copépodos calanoides. De la misma forma, los hallazgos morfológicos en algunas especies son de gran valor taxonómico para la diferenciación de especies.

The seasonal variations in biomass, abundance, and species composition of plankton in relation to hydrography were studied in saline lake Namuka Co, northern Tibet, China. The sampling was carried out at approximately monthly intervals from June 2001 to July 2002. The salinity ranged from 5.5 to 26 g/L. The mean annual air and water temperature showed a clear seasonal pattern, which was approximately 4.4 and 7.4°C, respectively, with the lowest water temperature in winter (from December to March, -1°C) and the highest in June and July (18°C). The results showed that 36 taxa of phytoplankton and 16 taxa of zooplankton were identified. Both the biomass and abundance of total phytoplankton were lower in the winter and peaked once or twice during the summer and spring in the early August (8.23 mg/L and 158.2 x 10 6 ind./L). The seasonal variation in total zooplankton biomass and abundance was characterized by lower values in both winter and early spring, and one maximum (90.5 mg/L and 935 ind. L -1 ) occurred in the late summer. Major phytoplankton species were Gloeothece linearis, Oscillatoria tenuis, Gloeocapsa punctata, Ctenocladus circinnatus, Ulothrix sp., and Spirogyra sp. And major zooplankton species included Vorticella campanula, Brachionus plicatilis, Daphniopsis tibetana, Cletocamptus dertersi, Arctodiaptomus stewartianus. The production of D. tibetana was 420.3 g m 3 a -1 . The total number of plankton species has a significant negative correlation with the salinity.

Species composition and parameters of biomass of net plankton were analyzed for four large and 35 small lakes from 10 areas located between 69.5° and 67.5°N and 87° and 92°E that were examined in July–August, 2001 and 2003–2004. In the composition of the first (dominant) and/or second (subdominant) species in the ranged row of the average biomass, the lakes were copepod in 78.8% of cases, in 67.3%, calanoid. The share of biomass of cladocerans in the total biomass of zooplankton exceeded 50% only in 31% of cases. By the frequency of occurrence as dominant or subdominant by biomass the first place is occupied by copepodites calanoid (34.6% of cases), the second, by sexually mature Heterocope appendiculata (26.9%), the third, by copepodites cyclopoid (17.3%), the fourth, by Polyphemus pediculus (15.4%), the fifth, by Acanthodiaptomus denticornis (13.5%), the sixth, by Bosmina cf. longispina (11.5%), the seventh, by Heterocope borealis (9.6%), the eighth, by Daphnia cf. longispina (7.7% of cases). For the first time in the region 14 species of crustacean zooplankton are given. The known range of some species and subspecies (for example, Chydorus biovatus, Camptocercus fennicus, Ophyoxus gracilis kolymensis, Arctodiaptomus acutilobatus, Acanthrodiaptomus tibetanus) is widened owing to the findings in the studied region. The groups of the areas are more similar in terms of zooplankton north to south than east to west; the number of the cladoceran species and the number of cladoceran lakes grew north to south and east to west, which corresponded to the general change of climate towards more mild north to south for similar altitudes and east to west for different altitudes from mountain areas to the low lands. The comparison of the species lists from different northern regions showed that the species diversity (total number of species) of cladocerans and copepods does not change significantly west to east. Distribution of species and changes in the zooplankton structure are discussed from the point of view of possible influence of the global warming.

Zooplankton species have evolved several adaptive strategies to minimize damage caused by exposure to solar ultraviolet radiation, but the environmental conditions favoring one strategy or another are not yet fully understood. Here, I quantified the concentration of photoprotective compounds (carotenoids and mycosporine-like amino acids or MAAs) and assessed the photorepair activity (photolyase assay) in populations of the calanoid copepod, Arctodiaptomus jurisowitchi and the cladocerans, Daphnia himalaya and D. longispina, from five high altitude lakes located in the Himalayan Region (Khumbu Valley, Nepal) between 4890 and 5440 m above sea level. The concentration and diversity of MAAs were low in copepods, as well as in seston samples. Significant differences in the concentration of MAAs among the five copepod populations were largely explained (96%) by the lake depth refuge (i.e., the fraction of the water column to which 1% of the surface UVR at 320 nm penetrates). Concentrations of carotenoids (mostly free astaxanthin) in copepods were among the highest reported in the literature. Similar to MAAs, the carotenoid concentration was inversely related to the lake depth refuge. The lowest concentration of photoprotective compounds in copepods was observed in a turbid glacier lake, whereas the highest was found in a shallow water body dominated by a benthic mat of filamentous green algae. Except for the presence of melanin in D. himalaya, no other photoprotective compounds were found in cladocerans. The assay of photolyase activity in A. jurisowitchi and D. himalaya suggested the absence of a photorepair mechanism. The results of this study indicate that the copepod populations from this relatively pristine alpine region rely mainly on the accumulation of carotenoids to minimize damage by UV radiation, a pattern that strongly contrasts with what is known for copepods from other alpine lakes, for instance, in the Alps. I hypothesize that this difference is attributed to nitrogen limitation of the MAA synthesis in phytoplankton from remote Himalayan lakes.

The zooplankton structure of large lakes (Noyon-Khol’, Shuram-Khol’, Borzu-Khol’, Many-Khol’, Kadysh, and Todzha) of the Todzha Depression has been studied. A comparison of the species composition, abundance, and biomass of zooplankton in the lakes was made. Rotifers have the largest species diversity: from 10 to 16 species, with Conochilus sp., Collotheca sp., Kellicottia longispina (Kellicott), and Asplanchna priodonta Gosse being the most abundant. Copepods are represented mostly by Arctodiaptomus paulseni (Sars), Eudiaptomus graciloides (Lilljeborg), Cyclops scutifer Sars, and Mesocyclops leuckarti Claus. Daphnia galeata Sars and Bosmina longispina Leydig are the dominant cladoceran species. It is shown that the zooplankton communities of the lakes in the Todzha Depression are characterized by a high degree of species composition similarity. Factors forming the taxonomic structure of pelagic zooplankton in the system of these lakes are displayed.

We analysed circumpolar samples from 68 lakes within the 10°C-July isotherm from Arctic Canada, Nunavut, Greenland, Svalbard, Eastern Siberia, the Beringia region, and Alaska. In total, we found 3 species of Anostraca, 17 of Diplostraca, 1 species of cyclopoid and 14 species of calanoid copepods. Our study identifies a wider distribution for some copepods—e.g. Eurytemora pacifica, Leptodiaptomus sicilis, Arctodiaptomus novosibiricus, Cyclops abyssorum—than previously known. Moreover, one anostracan species, Artemiopsis bungei, was recorded in North America for the first time; and one chydoriid, Chydorus gibbus, is a new species for Greenland. We observed that species richness of crustaceans is lower in lakes that were glaciated during the Quaternary period, compared to those not glaciated (e.g. Chukotski Peninsula, Siberia; Point Barrow, Alaska; and Disko Island, Greenland). This confirms the findings of classic studies: glaciation has strongly affected the biogeography of freshwater crustaceans in circumpolar areas.

Plankton data from 1997 to 2005 were used to examine impacts of a managed draw-down, subsequent drought and resulting historic low water levels (during 2000 and 2001) on the zooplankton of Lake Okeechobee, Florida. Prior to the drought the lake supported less than 150 ha of submerged vegetation. Following the drought, over 15,000 ha of submerged vegetation developed around the lake shore and conditions favored greater survival of age 0 fish. The zooplankton changed significantly from the pre- to post-drought period, including: (a) a near-complete loss of all dominant species of cladocerans and rotifers; and (b) an abrupt transition to a community with over 80% of total biomass comprised of Arctodiaptomus dorsalis, a calanoid copepod previously described as being resistant to fish predation. These changes persisted over a 5 year post-drought sampling period. In contrast, there were no systematic changes in biomass of bacteria, phytoplankton, inedible cyanobacteria, algal cell size, suspended solids, or any other physical or chemical attributes known to affect zooplankton in shallow lakes. Evidence points towards increased predation by fish, and perhaps invertebrates, as factors responsible for loss of cladocerans and rotifers following the drought, and indicates a need for future research to link changes in water level to shifts in predation pressure in this and other shallow lakes.

Lake Xochimilco is a eutrophic water body in Mexico City used by the local population for aquaculture and agriculture. Water level is maintained with inputs of partially treated waste water from the Cerro de la Estrella treatment plant. In this study we analysed the water quality at two sites of Lake Xochimilco, Lake Xaltocan and the Santa Cruz Canal using various indicators such as zooplankton diversity, saprobic indices, bacterial concentrations and physico-chemical variables. Eighty litres of water was filtered from Lake Xochimilco from each site, once a month from March to October of 2012, and the rotifers, cladocerans and copepods were enumerated and identified. Physico-chemical parameters such as temperature, pH, Secchi depth, water depth, nitrogen and phosphorus and chlorophyll a concentrations, and bacterial densities were measured. During the study we recorded 33 species of rotifers, the most abundant being Brachionus angularis, B. calyciflorus and B. havanaensis. Among the microcrustaceans the most abundant were the cladoceran Moina micrura and the copepods Acanthocyclops americanus and Arctodiaptomus dorsalis. The species diversity was around 2 bits/ind. and the saprobic index between 1.5-2.0, indicating that both sites were β meso-saprobic. At both sites nitrogen was Vibrio cholerae No-O1/No-O139) and the non-toxigenic (Vibrio cholerae No-O135) strains of the bacterium were recorded, closely associated with littoral rotifers and cladocerans particularly Brachionus quadridentatus and Alona sp. All variables indicate that these sites in Lake Xochimilco are eutrophic and highly contaminated and that the water quality needs to be improved.

The plankton copepod fauna of the Pollino National Park (South Italy) were studied for the first time. Plankton samples were collected from 5 ponds, and 2 of these ponds were sampled monthly for one year to study species’ seasonality. The length of adult specimens was measured to investigate body size variability. The variation of egg number in female egg sacs was evaluated for 2 species. Copepods were present in the plankton of the 5 ponds with a total of 10 species (2 Calanoida, 8 Cyclopoida), belonging to different genera. The 2 ponds which were studied in detail gave 7 and 8 species, respectively (only 1 calanoid per pond). Three species were exclusive to a single pond; only 1 species (the cyclopoid Eucyclops serrulatus) was found in all the 5 ponds. One calanoid (Arctodiaptomus kerkyrensis) and one cyclopoid (Tropocyclops prasinus) were perennial, with adults present in all the samples collected from the pond they inhabited. The second calanoid (Mixodiaptomus lilljeborgi) was found also under the snow-ice cover of the pond during winter, but was absent from summer-autumn samples. The adults of the remaining Cyclopoida species, in contrast, were generally absent from winter samples. All of the species showed adult females larger than males. Winter-spring adults were generally larger than the summer-autumn ones. The clutch size was directly correlated with the female body size. In a comparison between the 2 Calanoida, the one that inhabits the most stable pond (i.e. the pond with the smallest water-volume variation) showed many generations per year, and the smallest variation in clutch size and body size among generations. In the case of E. serrulatus, which populated both of the ponds, the body size of the population of the unstable pond showed a wider variability than that of the stable pond.

Two pairs of neighboring subalpine lakes located in the Northern Calcareous Alps of Austria were investigated. Each pair comprised a deeper lake containing European minnows (Phoxinus phoxinus ), and a corresponding shallower lake harboring Alpine newts (Triturus alpestris ) as top predators. Plankton successions within fish and amphibian lakes differed markedly from each other. Throughout the year rotifers numerically dominated within the minnow lakes, while pigmented copepods (Genera Heterocope, Acanthodiaptomus , Arctodiaptomus , Mixodiaptomus ) and Daphnia were prominent in the amphibian lakes, at least early during the ice-free period. We argue that size-selective predation by minnows was the ultimate reason for this predominance of smaller zooplankton. While one of the minnow lakes was characterized by a succession of spatially and temporally segregated rotifer species, the other minnow lake permitted the development of populations of small-sized Bosmina and Ceriodaphnia during summer, probably due to the existence of a strong oxycline allowing zooplankton crustaceans to avoid predation from shore-based shoals of minnows. Once trout were introduced into this lake, minnows were visibly reduced in abundance. Bosmina and Ceriodaphnia disappeared and Daphnia together with a predacious copepod (Heterocope ) emerged either from egg banks or arrived from nearby source populations. We argue that the crustacean communities within the fishless lakes were adapted to the comparatively weak predation rates of Alpine newts. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

The distributional patterns and diversity of the diaptomid calanoid copepods were analysed to assess the faunistic affinity of North and South America with respect to Mexico and Central America. In the Neotropical region, the most speciose genera of Diaptomidae are Leptodiaptomus and Mastigodiaptomus. The former genus is a Nearctic form, and Mastigodiaptomus is Neotropical. Based on the current distribution of their diversity, it is probable that these genera radiated into Mexico and Central America from North America and the insular Caribbean, respectively. Arctodiaptomus dorsalis is a primarily Palaearctic taxon, it is widely distributed between North and Central America. This species probably radiated in the Americas as a Tethyan derivate. Prionodiaptomus is the only member of the highly diverse South American diaptomid fauna that has expanded beyond the subcontinent. Despite the high diversity present in South America, its influence in Mexico and Central America appears to be weak; this is probably a consequence of the geologically recent union of the two main subcontinental landmasses. Mexico shares 33% of its species with NA, and no species are shared between NA and SA. For the Diaptomidae, the Nearctic influence is strongest in Mexico. (© 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

The zooplankton of 16 mountain lakes in the Taurus Range was studied during 1996 and 1997, and a total of 116 zooplankton taxa, comprising 69 rotifers, 33 cladocerans, 12 copepods, one anostracan, and one chonchostracan was identified. Four rotifers (Brachionus polyacanthus, Asplanchnopus hyalinus, Lecane haliclysta, Dissotrocha aculeata medio-aculeata) and one copepod (Arctodiaptomus (Rh.) alpinus) are new for Turkish inland waters, and they are illustrated.

We studied species composition and individual abundance of copepods in the surficial aquifer in short-hydroperiod habitats of Everglades National Park by collecting copepods from different depths at selected wells for two consecutive years. Subsurface copepod communities were dominated by surface copepods that colonized ground-water mainly at the beginning and at the end of the wet season, when ground-water levels dropped about 60 cm below ground level. Copepods entered ground-water, but decreases in community similarity with increasing distance between wells suggest that they did not disperse far from the input location. The five most abundant species were stygoxenes: Osphranticum labronectum, Arctodiaptomus floridanus, Orthocyclops modestus, Thermocyclops parvus, and Macrocyclops albidus. Two stygophiles were collected: Diacyclops nearcticus was abundant, whereas Elaphoidella marjoryae was rare. Elaphoidella fluviusherbae, and perhaps a Parastenocaris sp., were the only stygobites collected.

Aim To determine and analyse the distribution of the freshwater calanoid copepod (Diaptomidae and Pseudodiaptomidae) fauna of the Yucatan Peninsula (YP) and its relation to the geological history of this Neotropical karstic plain. Location The Yucatan Peninsula, Mexico. Methods Plotting of geo-referenced sites, analysis of local and regional geological history, analysis and comparison of regional and local records. Results The current composition and distribution of Diaptomidae and Pseudodiaptomidae in the YP mainly reflects recent, post-Pliocene colonization events. This invasion did not reach America, but only parts of Central America (CA). The presence of diaptomids in the continent since the pre-Cretaceous and the presumed post-Cretaceous (Palaeocene–Oligocene) radiation of Diaptomidae in Middle America suggest earlier colonizations of the YP. The marine transgressions kept most of the YP submerged in different geological periods, thus eliminating any original primary freshwater colonizers, such as the diaptomids. The periods of marine regression probably represented opportunities for new waves of diaptomid colonization of the YP. The latest dispersal of diaptomids in the YP during the Holocene (8000 yr bp) was probably an intermittent process because of the alternative dry and wet periods and interglacial transgressions. The presence of the Nearctic Leptodiaptomus and Arctodiaptomus in the YP and the current distribution of Mastigodiaptomus might represent remnants of earlier invasions of Diaptomidae in Middle America. The Neotropical Mastigodiaptomus probably originated in the Late Cretacic CA/proto-Antilles complex. Forms derived from a M. albuquerquensis type ancestor radiated into the YP leaving relatively isolated populations of three species in the northern half of the peninsula. The distribution of the brackish water Pseudodiaptomus marshi well inside the coastline might have resulted from stranding and subsequent adaptation of this species during a marine regression in the Bacalar formation; this agrees with the vision of this taxon as being in process of invasion of freshwater environments. Main conclusions It is not probable that the South American (SA) diaptomid fauna originated from an invasion of upper Neotropical/Nearctic forms. The current distribution of freshwater calanoid copepods reflects relatively recent, post-Pliocene biogeographical patterns, but probably older patterns are involved as well. The northern and eastern coasts of the Yucatan are the most recently colonized by diaptomids. Differing from other freshwater groups surveyed in the Yucatan that have marine relatives (i.e. fishes, amphipods, isopods, mysids, macrocrustaceans), there is no evidence of local vicariant events involving cave-dwelling forms or marine relicts in the diaptomid fauna of the YP.

[The free-living continental copepod fauna of the Yucatan Peninsula has been studied for decades; recent intensive surveys suggest that its biodiversity is higher than formerly realized. An updated, revised checklist of the Yucatan copepods is provided herein. This new list includes 59 species, more a than 30% increase from the most recent previous account. The Yucatan Peninsula has long been considered to have faunistic affinities with Central and Southern Mexico and with South America. A similarity analysis was performed using regional records of Copepoda and including two taxa, the orders Calanoida and Cyclopoida. Results from both groups suggest that the Yucatan copepod fauna diverges from that of Central Mexico. Central Mexico itself seems to be closest to the upper Central American fauna, an affinity explained by a longer geological connection. Overall, the Yucatan copepod fauna appears to have more biogeographic ties with Cuba and the insular Caribbean than with Central America or the rest of Mexico. The occurrence of nearctic diaptomids such as Arctodiaptomus and Leptodiaptomus in the Yucatan seems to be related to a general invasion of these calanoids that reached Central America and intermittently spread into the Yucatan Peninsula. With two endemic species in the Yucatan, Mastigodiaptomus appears to have become diversified in the peninsula, derived from other neotropical forms. The local high proportion of endemic forms of Copepoda and the particular geological history of the Yucatan make this karstic area a peculiar, separate entity within the neotropical region that should be studied in more detail. La fauna de copepodos de aguas continentales de la Peninsula de Yucatan ha sido estudiada por decadas; estudios taxonomicos recientes sugieren que su biodiversidad es particularmente elevada. Se presenta aqui una lista actualizada y revisada de los copepodos de la Peninsula de Yucatan. Esta lista incluye 59 especies, lo que representa un incremento de mas del 30% con respecto al mas reciente listado faunistico previo. Se ha considerado por mucho tiempo que la Peninsula de Yucatan tiene afinidades faunisticas con el centro y sur de Mexico y con America del Sur. Se realizo un analisis de similitud utilizando los registros faunisticos regionales de Copepoda; el analisis incluyo los ordenes Cyclopoida y los Calanoida como grupos independientes. Los resultados sugieren que la fauna de Yucatan es distinta a la del centro de Mexico; esta ultima subregion es mas semejante a la fauna de Centroamerica, explicable por una coneccion geologica mas prolongada. La fauna de copepodos de Yucatan parece estar mas relacionada con la de Cuba y las islas del Caribe que con America Central o con el resto de Mexico. La presencia de Diaptomidae nearticos, como Arctodiaptomus y Leptodiaptomus parece estar asociada a una invasion de estos taxa que alcanzo America Central y ocupo la peninsula de manera intermitente. Mastigodiaptomus parece haberse diversificado en la peninsula a partir de otras formas neotropicales. La elevada proporcion de formas consideradas endemicas y la peculiar historia geologica de la peninsula la convierten en una subregion de caracteristicas exclusivas dentro de la region neotropical., The free-living continental copepod fauna of the Yucatan Peninsula has been studied for decades; recent intensive surveys suggest that its biodiversity is higher than formerly realized. An updated, revised checklist of the Yucatan copepods is provided herein. This new list includes 59 species, more a than 30% increase from the most recent previous account. The Yucatan Peninsula has long been considered to have faunistic affinities with Central and Southern Mexico and with South America. A similarity analysis was performed using regional records of Copepoda and including two taxa, the orders Calanoida and Cyclopoida. Results from both groups suggest that the Yucatan copepod fauna diverges from that of Central Mexico. Central Mexico itself seems to be closest to the upper Central American fauna, an affinity explained by a longer geological connection. Overall, the Yucatan copepod fauna appears to have more biogeographic ties with Cuba and the insular Caribbean than with Central America or the rest of Mexico. The occurrence of nearctic diaptomids such as Arctodiaptomus and Leptodiaptomus in the Yucatan seems to be related to a general invasion of these calanoids that reached Central America and intermittently spread into the Yucatan Peninsula. With two endemic species in the Yucatan, Mastigodiaptomus appears to have become diversified in the peninsula, derived from other neotropical forms. The local high proportion of endemic forms of Copepoda and the particular geological history of the Yucatan make this karstic area a peculiar, separate entity within the neotropical region that should be studied in more detail. La fauna de copepodos de aguas continentales de la Peninsula de Yucatan ha sido estudiada por decadas; estudios taxonomicos recientes sugieren que su biodiversidad es particularmente elevada. Se presenta aqui una lista actualizada y revisada de los copepodos de la Peninsula de Yucatan. Esta lista incluye 59 especies, lo que representa un incremento de mas del 30% con respecto al mas reciente listado faunistico previo. Se ha considerado por mucho tiempo que la Peninsula de Yucatan tiene afinidades faunisticas con el centro y sur de Mexico y con America del Sur. Se realizo un analisis de similitud utilizando los registros faunisticos regionales de Copepoda; el analisis incluyo los ordenes Cyclopoida y los Calanoida como grupos independientes. Los resultados sugieren que la fauna de Yucatan es distinta a la del centro de Mexico; esta ultima subregion es mas semejante a la fauna de Centroamerica, explicable por una coneccion geologica mas prolongada. La fauna de copepodos de Yucatan parece estar mas relacionada con la de Cuba y las islas del Caribe que con America Central o con el resto de Mexico. La presencia de Diaptomidae nearticos, como Arctodiaptomus y Leptodiaptomus parece estar asociada a una invasion de estos taxa que alcanzo America Central y ocupo la peninsula de manera intermitente. Mastigodiaptomus parece haberse diversificado en la peninsula a partir de otras formas neotropicales. La elevada proporcion de formas consideradas endemicas y la peculiar historia geologica de la peninsula la convierten en una subregion de caracteristicas exclusivas dentro de la region neotropical.]

The effect of treatment water containing chemicals released by Gammarus lacustris or crushed/injured Arctodiaptomus salinus induced changes in vertical distribution of Arctodiaptomus in laboratory conditions. With food concentration in the medium corresponding to the maximum of algae concentration in Shira lake, A. salinus in an experimental vessel was situated higher than in the control. Average population depth of A. salinus decreased as the inoculation density of G. lacustris increased.

The trophic status of Lake Mogan a shallow, alluvial lake in Central Anatolia, was assessed during a nine-month survey in 1994, including community structure and seasonal distribution of planktonic organisms. Bacillariophyta were dominant among the phytoplankton, followed by Chlorophyta, Cyanophyta, Cryptophyta, Euglenophyta and Dinophyta. Among the zooplankton, Arctodiaptomus bacillifer, Diaphanosoma lacustris and Keratella quadrata were the dominant species. Rotifers were most abundant in spring, Cladocera in summer and copepods in autumn. A rapid increase in zooplankton density correlated with a rise in temperature of 8°C and an increase in the chlorophyll concentration during summer. A total of 21 species of Rotifera, 6 species of Cladocera and 2 species of Copepoda have been identified, in addition to 90 species (from 8 genera) of phytoplanktonic organisms.

A flow-through method was employed to study the algal part of the diet spectrum of the calanoid Arctodiaptomus salinus in the surface layer of the lake and in the phytoplankton biomass maximum zone (10 m deep). Daily consumption rates of this calanoid differed markedly in these layers, being 1 and 11 μg ind −1 d−1, respectively. The cyanobacterial taxa, Lyngbya contorta and Microcystis sp., accounted for more than a half of the ration. Nevertheless, the negative Ivlev electivity coefficient indicated that Arctodiaptomus prefers none of these two taxa. The low measured uptakes suggest that the energy expenditure is compensated by other resources, presumably microzooplankton and detritus.

During the wet season of 1999–2000, we studied the effects of the hydroperiod and other physical and chemical variables on planktonic copepod communities from six stations in Everglades National Park. Two stations were located in a slough (Taylor Slough 1, Taylor Slough 2) and four stations in the marl prairies of the Rocky Glades (Long Pine Key 7, Long Pine Key 8, Pa-hay-okee, Chekika). During the period of investigation, Taylor Slough sites had the longest hydroperiods, together with Pa-hay-okee, which is located near the eastern edge of Shark River Slough. Long Pine Key 7 and Long Pine Key 8 had the shortest hydroperiods, and Chekika had an intermediate hydroperiod. The pineland edge sites in the southern Rocky Glades (Long Pine Key) had higher numbers of individuals, and high percentages of larval stages, especially at the end of the wet season. The pineland ecotone is morphologically very heterogeneous, with solution holes in the limestone bedrock that provide below-ground refugia when there is no water on the marsh surface. The slough stations had the lowest numbers of individuals, as well as Chekika in the Rocky Glades, probably as a consequence of the altered water quality and hydropatterns caused by water management structures and operations We collected two species of calanoids, 18 cyclopoids, and three harpacticoids. The most abundant species were Acanthocyclops robustus, Tropocyclops prasinus mexicanus, Arctodiaptomus floridanus, Mesocyclops americanus, Macrocyclops albidus, Osphranticum labronectum, Microcyclops varicans, Microcyclops rubellus, Eucyclops conrowae, and Mesocyclops edax. Of these species, T. prasinus mexicanus and A. floridanus seemed to be adapted to short-hydroperiod habitats, M. rubellus and M. varicans to longer hydroperiod habitats, and E. conrowae to high conductivity habitats. Acanthocyclops robustus, M. albidus, and O. labronectum were dominant regardless of hydroperiod. As regards the temporal distribution, A. robustus was abundant throughout the entire wet season, M. edax, M. rubellus, M. americanus and M. varicans were most abundant in mid-wet season, in September–October, and T. prasinus mexicanus, M. albidus, and E. conrowae were abundant late in the wet season, in winter. The two calanoids only slightly overlapped in time: A. floridanus was abundant at the beginning of the wet season, in July–August, and O. labronectum was abundant at the end of the wet season, in December.

Background: To date, only scarce information is available about the diaptomid copepods of the Middle East despite the ecological and biogeographical importance of the family Diaptomidae in the inland waters of the Holarctic region. Moreover, the taxonomic status of some of the taxa occurring in the area is in need of revision. We studied crustaceans collected from temporary and permanent lentic water bodies in Israel with the aim of providing an updated census of the diaptomid copepods occurring in the country. Furthermore, we morphologically and genetically analysed samples of Arctodiaptomus similis s.l. to shed light on its taxonomy. Results: Five diaptomid taxa were collected during this survey. Among these, Phyllodiaptomus blanci is new for the country and the whole circum-Mediterranean area and might be an allochthonous species of eastern origin. Within the collected samples, we singled out two parapatric groups of populations within A. similis s.l.; these consistently differ both based on morphology (chaetotaxy of the left male antennule) and molecular data (divergence over 17% at the mitochondrial gene for the cytochrome b). We thus attribute the full species rank to Arctodiaptomus irregularis Dimentman & Por, 1985 stat. rev., originally described as a subspecies of the widespread species Arctodiaptomus similis (Baird, 1859). Conclusions: We critically evaluated all species hitherto reported for Israeli inland waters. Considering both the confirmed literature data and the new findings, Israeli diaptomid fauna is composed of at least seven species. However, the need for further surveys in the Middle East and for detailed systematic revisions of some controversial taxa is stressed. Our results on the systematics of A. similis s.l. illustrate the importance of implementing molecular analyses when investigating diversity patterns of groups which are difficult to resolve based on morphology alone.

In 1991 about twenty-five age 2+ specimens of the Arctic charr (Salvelinus alpinus (L.) (length between 100 and 130 mm) were introduced into the fishless small mountain lake Dvojno Jezero (= Twin Lake) (area 0.5+0.4 ha; max. depth 8 m, altitude 1670 m) in NW Slovenia. The first spawning of the Arctic charr was observed in autumn 1994 and regularly each year thereafter. Fish of different sizes were observed from 1995 onward each year but a fish census was never carried out. Autumn zooplankton samples, collected before the introduction of Arctic charr, contained adults (including ovigerous females) of two copepod species: Cyclops abyssorum tatricus and Arctodiaptomus alpinus. No planktonic Cladocera were found. Seven years after the introduction of fish standing crop of zooplankton declined 100-fold. The zooplankton contained only a few copepodites (IV and V) of C. a. tatricus. Simultaneously, water transparency declined and the concentration of chlorophyll a increased and filamentous green algae and picoplankton became abundant in the littoral zone of both lakes.

During May and June 1991, the biological and ecological features of sixteen aquatic localities in Zhanjiakou region, Hebei, northern China, were investigated. Their salinity ranged from 0.98 to 175.2 g L−1. Fish and benthic macroinvertebrates were depauperate. 116 samples were collected. 91 species (or genera) of phytoplankton and 94 species of zooplankton were recorded. In most of the saline lakes, Cl− and Na+ were dominant, and alkalinity and pH values were higher. For phytoplankton, major species were Chroococcus minutus, Oscillatoria tenuis [blue-green algae]; Chlamydomonas spp., Chlorococcus spp., Chlorella vulgaris, Crucigenia quadrata, Dunaliella salina, Kirchneriella contorta, Oocystis lacustris, Scenedesmus acuminatus [green algae] and Cyclotella meneghiniana, Navicula spp., Nitzschia spp. [diatoms]. Other phytoplankton taxa present included: Cryptomonas erosa, Chroomonas acuta, Chromulina pascheri, Euglena viridis. For zooplankton, major species included: Vorticella campanula, Epistylis breviramosa, Euplotes terricola [protozoa] Brachionus plicatilis, Hexarthra fennica, Keratella quadrata, Notholca acuminata quadrata [Rotifera] Daphnia magna, D.longispina [‘Cladocera’] Artemia spp. [Anostraca] Arctodiaptomus rectispinosus and Cyclops vicinus [Copepoda]. The species composition, distribution, salinity tolerance of planktonic forms in inland saline waters are discussed and their relationship with certain environmental factors.

We surveyed the zooplankton community of Lake Mogan, which has been undergoing gradual eutrophication in recent decades. The zooplankton was dominated by Rotifera (91.1%), followed by Copepoda (7.7%) and Cladocera (1.2%). The dominant species were Filinia longiseta, Brachionus angularis, Synchaeta pectinata, Anureopsis fissa, Polyarthra vulgaris, Lecane clostrocerca, Arctodiaptomus acutilobatus, Hexarthra oxyuris, Polyarhtra dolichoptera and Arctodiaptomus bacillifer. The zooplankton composition of Lake Mogan has changed dramatically since the 1970s when rotifers did not dominate the community.

This paper reports, describes, and depicts the calanoid Sinodiaptomus sarsi (Rylov, 1923) from Turkey. This species is living in the Devegecidi dam lake, near Diyarbakir, in the copepods of Arctodiaptomus acutilobatus (G.O. Sars).