Temporary Rain Pools Research Articles

Distribution of the genus Dendrocephalus (Crustacea, Branchiopoda, Anostraca) in Argentina: a review

The fairy shrimp Dendrocephalus brasiliensis was first found in Brazil in temporary rainpools in the northeastern states of Piauí and Bahia. Gradually, new records were added in other northeastern states up to the state of Minas Gerais, in the Southeast region of the country. The species was even found south of Minas Gerais in the state of São Paulo, but not in wild conditions, but in rearing tanks associated with aquaculture practices. On the other hand, D. brasiliensis was reported much further south, in Argentina, living in temporary natural environments, in northern and central provinces and even in a Patagonian province. The wide latitudinal distribution of the species with a striking gap between Brazilian and Argentinean records has been questioned by some researchers. In the present paper we reexamine the Argentinean records of D. brasiliensis and provide an update of the geographic distribution of the species of the genus in this country.

Laboratory and microcosm experiments reveal contrasted adaptive responses to ammonia and water mineralisation in aquatic stages of the sibling species Anopheles gambiae (sensu stricto) and Anopheles coluzzii

BackgroundThe sibling species of the malaria mosquito, Anopheles gambiae (sensu stricto) and Anopheles coluzzii co-exist in many parts of West Africa and are thought to have recently diverged through a process of ecological speciation with gene flow. Divergent larval ecological adaptations, resulting in Genotype-by-Environment (G × E) interactions, have been proposed as important drivers of speciation in these species. In West Africa, An. coluzzii tends to be associated with permanent man-made larval habitats such as irrigated rice fields, which are typically more eutrophic and mineral and ammonia-rich than the temporary rain pools exploited by An. gambiae (s.s.)MethodsTo highlight G × E interactions at the larval stage and their possible role in ecological speciation of these species, we first investigated the effect of exposure to ammonium hydroxide and water mineralisation on larval developmental success. Mosquito larvae were exposed to two water sources and increasing ammonia concentrations in small containers until adult emergence. In a second experiment, larval developmental success was compared across two contrasted microcosms to highlight G × E interactions under conditions such as those found in the natural environment.ResultsThe first experiment revealed significant G × E interactions in developmental success and phenotypic quality for both species in response to increasing ammonia concentrations and water mineralisation. The An. coluzzii strain outperformed the An. gambiae (s.s.) strain under limited conditions that were closer to more eutrophic habitats. The second experiment revealed divergent crisscrossing reaction norms in the developmental success of the sibling species in the two contrasted larval environments. As expected, An. coluzzii had higher emergence rates in the rice paddy environment with emerging adults of superior phenotypic quality compared to An. gambiae (s.s.), and vice versa, in the rain puddle environment.ConclusionsEvidence for such G × E interactions lends support to the hypothesis that divergent larval adaptations to the environmental conditions found in man-made habitats such as rice fields in An. coluzzii may have been an important driver of its ecological speciation. Graphical

Natural History and Reproductive Data of <i>Kurixalus yangi</i> (Anura: Rhacophoridae) in Nagaland, India

The genus Kurixalus Ye, Fei et Dubois, 1999 (Rhacophoridae Hoffman, 1932) is a small and taxonomically difficult group of treefrogs for which biological and reproductive data are missing for most of the species. A recent study of the K. odontotarsus species group (Yu et al., 2017a) revealed numerous undescribed lineages. Among them a lineage comprising specimens from Myanmar and western Yunnan, China was described as K. yangi. We report here the presence of a population of this species from Nagaland, North East India, identified by DNA barcoding of the 16S rRNA gene and morphology. A pair of adults found in amplexus is described morphologically. Data on reproduction and developmental mode were until now unknown for the continental species of this genus. Observation of reproduction in the field of K. yangi from Nagaland provided us data on its reproductive activity including spawning behavior and reproductive mode, and details on the larval developmental timing. The tadpole of this species is described for the first time including buccal anatomy. Adults are commonly found in the stumps of bamboo internodes. They breed in forest ponds, temporary rain pools or rain water tanks. Breeding activity starts from mid-April till late part of July. Unpigmented eggs measure 2.4 – 2.7 mm and are laid underwater. Under natural conditions (air temperature 18 – 30°C, water temperature 12 – 24°C), the frog complete its larval life cycle in 47 days. The tadpole shows a «classical» pond-dwelling morphology and reproductive mode. These reproductive data are compared to the Taiwanese species for which the developmental mode is well known and the evolution of the reproductive modes within the genus is discussed.

The large branchiopod, Triops cancriformis simplex (Gihi, 1921) (Crustacea: Notostraca) in temporary rain pools, recorded for the first time in Taif-KSA

The present species Triops cancriformis simplex was not recorded in Taif and Kingdom of Saudi Arabia before. The present work is a confirmatory study to indicate the identity of this species in the ephemeral freshwater bodies in Taif, KSA and to ascertain that, if there is any other Triops species in the same area or not. Four sites were investigated in Taif governorate; Wadi Al-Arj, Saysed, Jabajeb pool and Ghadeer Al-Banat. The animal was not recorded in the first two sites all the year. The specimens were collected from Jabajeb pool on Al-Hada road and Ghadeer Al-Banat at Al-Roddaf region. No specimens were found in these sites during winter and autumn but they start in late spring and summer. One hundred and seven specimens were collected from both sites in this period. The animal was morphologically described to be distinguished from the other large branchiopods species. The supra-anal plate is absent, the dorsal organ of the present species is rounded, second maxilla is present, no supernumerary spines on apodous rings, the carina of T. c. simplex is smooth without spines in front of its terminal spine and presence of small spines on the furca.

Influence of surface water availability on mammal distributions in Nonggang National Nature Reserve, Guangxi, China

Surface water is a major limiting factor affecting animal activities in karst ecosystems. From March, 2006 to June, 2007 and from October, 2010 to May, 2011, infra-red camera traps were installed along animal trails and temporary rain pools in Nonggang National Nature Reserve, Guangxi, China, to monitor mammal diversity and relative abundance. In total, 19 species from 17 genera, 12 families, and 5 orders were recorded, including two State Key Protection Class I species, the François' langur (Trachypithecus francoisi) and Assam macaque (Macaca assamensis). Although 42% of species only occurred in one of the microhabitats, differences in species assemblages between trails and pools were not significant. The results of our observation indicated that camera trapping was effective in monitoring medium to large sized mammals, and for recording illegal hunting. In addition, our results suggest that authorities should reinforce patrolling, especially at water pools during the dry season, and eradicate unsustainable extraction of underground water. Moreover, based on the advantages of large inhibited environments to animal species, especially to large predators, we also recommend connecting the three isolated sections of the reserve to promote species recovery and dispersal.

Association of immature mosquitoes and predatory insects in urban rain pools

Distribution among pools of six mosquito species and 23 predatory insect taxa were studied in temporary rain pools during the summer and fall season in Buenos Aires city. Both mosquito immatures and predators were disproportionally more abundant in pools with high flooded surface, depth, and duration. Mosquito immatures differed in their habitat use with respect to predators. Among mosquitoes, Ochlerotatus albifasciatus showed a different pattern when compared to the remaining culicids. More culicid and predatory insect taxa colonized the pools in those flooding events of longer duration. Ochlerotatus albifasciatus was the only mosquito species recorded during short duration events and the first one in colonizing the pools in long duration events. This species shared the pools mainly with early arriving adult predators. Three Culex species were recorded later and showed higher coexistence with most of the predatory taxa, mainly immatures of the genera Tropisternus, Rhantus, Liodessus, and Belostoma. A high heterogeneity between pools and seasons was observed. Multiple regression analyses showed a negative relationship of per capita change of Culex species with large-sized predators only in those cases where predators were collected in high abundances during the summer. No negative relationship of predators was detected in relation to per capita change and abundance of Ochlerotatus albifasciatus. Differences in duration of about two to three weeks seemed to significantly affect the abundance of both culicid and predatory taxa, suggesting that the urban pools analyzed in this study are on the extreme of suitable conditions for these aquatic insects.

El Niño Southern Oscillation (ENSO) and annual malaria incidence in Southern Africa

We evaluated the association between annual malaria incidence and El Niño Southern Oscillation (ENSO) as measured by the Southern Oscillation Index (SOI) in five countries in Southern Africa from 1988 to 1999. Below normal incidence of malaria synchronised with a negative SOI (El Niño) and above normal incidence with a positive SOI (La Niña), which lead to dry and wet weather conditions, respectively. In most countries there was a positive relationship between SOI and annual malaria incidence, especially where Anopheles arabiensis is a major vector. This mosquito breeds in temporary rain pools and is highly sensitive to fluctuations in weather conditions. South Africa and Swaziland have the most reliable data and showed the strongest associations, but the picture there may also be compounded by the moderating effect of other oscillatory systems in the Indian Ocean. The impact of ENSO also varies over time within countries, depending on existing malaria control efforts and response capacity. There remains a need for quantitative studies that at the same time consider both ENSO-driven climate anomalies and non-ENSO factors influencing epidemic risk potential to assess their relative importance in order to provide an empirical basis for malaria epidemic forecasting models.

The neotropical genusDendrocephalus(Crustacea: Anostraca: Thamnocephalidae) in Brazil (South America), with a description of two new species

Two new species in the neotropical genus Dendrocephalus (Anostraca, Thamnocephalidae) are described from Brazil. Dendrocephalus orientalis n. sp., occurs in temporary rainpools in the eastern part of Brazil in the States of Paraiba and Bahia (Nordeste region). Dendrocephalus goiasensis n. sp. inhabits a temporary rainpool in the ‘cerrados’ in the State of Goias (Centro-Oeste region). The descriptions are based principally on male morphology, with a detailed study of the frontal appendage (basal part of the arms, branch 1V, 2A, and 2D), and of the endopodites of the first four thoracopods. Cyst morphology is also described using scanning electron microscopy. Differential diagnoses of these two species are presented. New records of Dendrocephalus brasiliensis Pesta, provide a better idea of its distribution range in Brazil. A dichotomous key to Brazilian dendrocephalids is included.

Diagnostic Features of Rana danieli (Anura: Ranidae) Tadpoles

Tadpoles of Rana danieli Pillai and Chanda were collected from temporary rain pools in marshy places at Umling situated at 296 m above sea level (91° 48’ E , 25°58’ N) about 65 km north of Shillong at Meghalaya hills. They are characterised by the keratodont formula 1:1+1/1+2:2, the presence of poison glands on the ventral and lateral abdominal surface, and a lateral line system on head and trunk region. Their structural features confirm the allocation of this species to the subgenus Hylarana.

Rainpools as breeding and dispersal sites of mosquitoes and other aquatic insects in the Central Negev Desert

During a faunistic survey of temporary rainpools of the Central Negev, the following mosquito species were found: Culiseta longiareolata (Macquart), Culex laticinctus Edwards and Culex adairi Kirkpatrick. Physico-chemical features of the rainpools were recorded. C. longiareolata breeding sites were found under a wider range of abiotic conditions (temperature, conductivity, pH and various ions) than those of the other species. The most restricted species was C. adairi. Characteristics of the mosquitoes’ breeding sites and the role played by temporary rainpools in the distribution of mosquitoes across the Negev Desert are discussed. A dispersal mechanism for aquatic desert insects is proposed involving the use of temporary pools as stepping stones to connect the oasis refuges.

Water Control and Desertification, the Resettled Nomads of Deh Luran, Iran

The wind blows south from the Zagros Mountains and Deh Luran (the village of the Lurs) wakes to the overpowering smell of sulphur on a cold winter morning. It is the third time in a week that Abi Garm, the local spring to the north whose sulphurous fumes have even killed unwary bathers, dominates the senses of Deh Luran. Abi Garm cannot be used for drinking; potable water comes from a sweet spring 25 kilometers away, carried in an old truck and sold by the gallon. When it rains the truck gets bogged down in the road across the seasonal swamp and the women of Deh Luran fetch water from temporary rain pools and puddles. Abi Garm is, nonetheless, the reason for Deh Luran's existence. Its brackish waters flow through the village compounds and streets in an anastomosing pattern before irrigating the fields below.

The fauna of temporary rain pools in Eastern New South Wales

The fauna of temporary rain pools in Eastern New South Wales

The effects of size-selective predation and environmental variation on the distribution and abundance of a Chironomid, Paraborniella tonnoiri Freeman

Larvae of the Australian chironomid P. tonnoiri live in temporary rainpools and aestivate in the dry mud during the summer drought. Over most of their range, they are restricted to large, deep, vegetated pools. A number of factors influence population numbers, but the most critical in determining the species' distribution is the presence of another chironomid, Allotrissocladius sp. Fourth-instar Allotrissocladius larvae kill P. tonnoiri when the latter are in first and possibly second instar. The deep, vegetated pools have ample food available when P. tonnoiri breeds, so young larvae grow rapidly through their early instars and soon cease to be vulnerable. In shallower, non-vegetated pools, with much less food, the larvae grow more slowly, are vulnerable for longer, and are consequently eliminated. P. tonnoiri is also absent from areas where low temperatures during early life may slow its growth, and it seems likely that the same mechanism is responsible. The study thus suggests that it may seldom be enough to know about the gross structure and physical characteristics of an ecosystem in order to predict whether or not a species will persist in it-it is also necessary to know some of the details of when and how it interacts with others.

Field Testing of Insecticides Used in Mosquito Control, and a Description of the Bioassay Technique Used in Temporary Pools1

Field trials were conducted to determine the effective control period of various insecticides used as mosquito larvicides. Dursban®, ( O,O -diethyl O -(3,5,6-trichloro-2-pyridyl) phosphorothioate), Abate® ( O,O -dimethyl phosphorothioate O,O -diester with 4,4'-thiodiphenol), malathion, fenthion, propoxur, methoxychlor, and DDT were evaluated using a bioassay technique. The bioassay used in temporary rain pools is described. Insecticides were tested in early spring, following winter applications at heavy rates. The effective control period in summer was evaluated at standard and heavy rates of application. Heavy rates increased the effective control period of most chemicals tested.

Triops (Entomostraca) eggs killed only by boiling.

Temporary rainpools near Khartoum, Sudan, are inhabited by the notostracan crustacean Triops which completes its life cycle within 4 weeks. The annual rains fall in late summer, and throughout the winter and early summer the eggs of Triops remain in the dried mud or dust where they may be exposed to temperatures up to 80 degrees C. Laboratory experiments show that they can withstand temperatures up to within 1 degrees C of boiling, but are killed in partial vacuum by 70 degrees C, at atmospheric pressure by 100 degrees C, or under pressure by 105 degrees C. Exposure to high temperature seems to be necessary to break the egg diapause.

Some Adaptations of Limnadia stanleyana King (Crustacea: Branchiopoda: Conchostraca) to a Temporary Freshwater Environment

Limnadia stanleyana King (Crustacea: Conchostraca) which inhabits temporary rainpools near Sydney, Australia, was studied to determine how it survives in this severe environment. Drying of the pools in which the species lives frequently kills its freeswimming stages, though eggs are drought-resistant (Bishop 1968). Eggs enter diapause in autumn and do not hatch during the cooler months of the year when the animals have a reduced chance of attaining sexual maturity before pools dry (Bishop 1967). Climate has further, more profound effects as the water level of pools is controlled by the local precipitation/evaporation ratio. Near Sydney the rainfall is irregularly distributed throughout the year and it is impossible to predict when a pool will fill or for how long it will contain water. This paper discusses some adaptations that enable the species to counteract this unpredictability of the environment. Conchostracans in a pool are frequently killed by drying before they can reproduce and the species has to withstand such population crashes if it is to survive in the pool. The following strategies are theoretical possibilities: (a) The species may recolonize the pool when this has dried and then refilled. (b) Some part of the population may be kept as a drought-resistant reserve in case the rest of the animals are killed by desiccation. (c) The species may evolve mechanisms by which it increases its chances of reproducing before the pool dries. Longhurst (1955) attributed the wide distribution of some species of Notostraca to the effectiveness of their eggs as dispersive agents. Proctor (1964) found that eggs of several branchiopods survived passage through the gut of waterfowl and were dispersed by them. Dispersal of eggs could result in recolonization of pools by L. stanleyana after drying had killed previous populations. Gillett (1955a, b) investigated a genetic mechanism that restrained some eggs of mosquitoes (genus Aedes) from hatching to form a reserve in case larvae were destroyed by premature drying of the habitat. (Aedes inhabit temporary pools and the eggs of some species are drought-resistant (Clements 1963).) Some branchiopods hatch only soon after their pool habitat fills with rain-water. This has obvious adaptive value as it maximizes the period over which post-embryonic stages can grow and reproduce thereby enabling the species to make the most effective use of the time the habitat is favourable. Hall (1959, 1961) concluded that development of eggs of Chirocephalus diaphanus Prevost (Anostraca) was inhibited in water deeper than 20 cm. Moore (1963) did not find that this was the case in Streptocephalus seali Ryder and Eubranchipus holmani (Ryder) (Anostraca). He suggested that eggs of these species

Notes on the ecology and entomostracan fauna of temporary rainpools of in Israel

The seasonal distribution of Cladocera and Copepoda in the Holon Rainpool near Tel-Aviv, Israel, was studied. Plankton was also collected from 16 other rainpools along the coastal plain of Israel and compared with the plankton of the Holon Pool. Environmental factors, such as water depth, temperature, dissolved oxygen, pH and alkalinity were recorded weekly at the Holon Pool. The interaction of temperature and water depth is discussed; a temporary thermal stratification occurs in this shallow rainpool. Daily as well as seasonal fluctuations in temperature, pH, dissolved oxygen and alkalinity are described and discussed. A positive correlation was found between total alkalinity and the density of Diaptomus wierzejskii. The succession of species during two seasons is described, and appears to be fairly constant. New localities for Alona elegans, Hemidiaptomus gurneyi and Acanthocyclops bicuspidatus are recorded.

EVOLUTION IN THE NOTOSTRACA

The Notostraca are phyllopod Crustacea in which the carapace is shield-shaped and covers the anterior part of the body; together with other phyllopods, they are considered to be relatively unevolved Crustacea-there is a high, but irregular, number of appendages (forty to sixty pairs are usual) and the segmentation of the body is anameristic. It is characteristic of phyllopods that they occur in temporary rain pools, generally in arid or steppe country where such pools are common, and are unable to maintain themselves in the face of competition from higher Crustacea or Insecta (Ard6, 1947). The survival of such primitive and vulnerable animals poses an interesting problem-the key to which may lie in their main adaptation to a temporary habitat, the drought-resistant egg. The possession of such an egg, from which hatching normally occurs only after desiccation, is an obvious prerequisite for the exploitation of a temporary freshwater habitat by a group of animals which do not have the capacities of aerial migration which the Insects possess. These drought-resistant eggs of phyllopods are the only possible means of dispersal for the group, for the pools in which the animals occur are isolated from one another, and are only rarely part of a stream system along which dispersal of adults would be possible. The eggs are small, light in weight because of their dry alveolar shells, and are sticky when laid in at least one genus (Triops, Notostraca); further, the eggs of some Anostraca are known to retain viability after passing through the guts of Amphibia (Mathias, 1937). These facts suggest several possible means of dispersal-in or upon larger animals, attached to dry pieces of wind-blown vegetation, or airborne singly in wind currents (a desert dust-devil will whirl particles much denser than the eggs of phyllopods high into the air). That 'these passive means of dispersal are effective is quite clearly shown by the ubiquitous occurrence of phyllopods in suitable pools wherever these occur. Notostraca occur on such isolated oceanic islands as the Hawaiian group, and in the few suitable pools that the rainy English climate permits. The phyllopods show another characteristic of passively distributed invertebrates-that of very widely spread, sometimes almost cosmopolitan species; in a recent study of the Notostraca for a systematic revision I found that Triops longicaudatus, which Linder (1952) showed was the only species of the genus in the Americas, extends from the West Indies through Central America and right across the Pacific to Japan by way of the Galapagoes, Oahu and New Caledonia. In all this area there is virtually no morphological change (Longhurst, 1955). These facts of dispersal and geographical distribution seem to me to explain the survival of the phyllopods. The initial arthropod invasion of temporary pools may well have been performed by the primitive fresh-water Crustacean fauna and has radiated into the forms of phyllopods we see today-the carnivorous Notostraca, the pelagic Anostraca, and the burrowing, detritus-feeding Conchostraca. This early fauna would have spread and occupied at least a high proportion of the suitable pools, and such a cosmopolitan occupation would have effectively prevented any geographically iso-

Amphibians and Reptiles of Tinian Island

The following report is based on specimens collected and observations made by the author from May 31, 1945, to October 17, 1945, while on duty with a service group of the Army Air Forces on Tinian Island, Marianas Group, in the western Pacific Ocean. The average temperature was reported to be approximately 800 F. The humidity was high. In the later months there were heavy rainswhich caused considerable erosion and formed temporary rain pools. Hagoi Lake was the one fresh water lake seen on the Island. Insects outnumbered other invertebrates which included large and small land crabs, and a large number of land snails, two to three inches in diameter. The eighteen species of birds observed have previously been recorded.* Rats and mice (presumably Rattus and Mus) were the only mammals observed. Sugar cane grew on most of the lower areas. Bananas, breadfruit, and papayas grew on the slopes and hills. Tinian lacks the extensive tropical forests that occur on Saipan only three miles distant to the northeast. Much assistance in the collecting of specimens was given by Major William B. S. Thomas, M.C. and Sgt. Eugene Cypert, Medical Department. Thanks are tendered to Dr. Edward H. Taylor for assistance in identifying the specimens and to Professor E. Raymond Hall for assistance with the present account.