Freshwater Shrimp Species Research Articles

FRESHWATER SHRIMP EFFECTS ON DETRITAL PROCESSING AND NUTRIENTS IN A TROPICAL HEADWATER STREAM

In this paper, we report on a whole-pool manipulation of leaf litter decomposition in a tropical stream following a hurricane. The study was designed to distinguish how decapod species comprising two functional feeding guilds alter rates and magnitudes of leaf litter processing and nutrient release linking the detrital food web with the overall producer–consumer food web. Streams of the Luquillo Experimental Forest, Puerto Rico, are dominated numerically by two freshwater shrimp species (Atya lanipes and Xiphocaris elongata). To determine how these shrimp affected detrital processing following large leaf inputs associated with a hurricane, we manipulated the presence or absence of two species of shrimp in six fenced pools of a headwater stream with hurricane levels of Cecropia leaf litter over a 23-d period. The experiment was designed to determine how the two different shrimp affected: (1) the rate and amount of size fractionation of leaf material; (2) the localized nutrient concentrations in the pools; ...

The Freshwater Decapod Crustaceans of Halmahera, Indonesia

Twenty-six species of freshwater shrimps and crabs, belonging to 14 genera of four families (Atyidae, Palaemonidae, Parathelphusidae, and Grapsidae) are reported from Halmahera, Indonesia. Of them, 10 are new records for the island while one species of Macrobrachium is here described as new. Description for new species, diagnoses for poorly known species, and taxonomic discussions for all species are provided.

On the relative importance of pool morphology and woody debris to distributions of shrimp in a Puerto Rican headwater stream

In this paper, we report the sizes and distributional orientation of woody debris in a headwater rainforest stream in the Luquillo Experimental Forest (LEF), Puerto Rico. We also provide results of a 4-month study of a wood addition experiment designed to increase cover for benthic macroinvertebrates (freshwater shrimp). We added branch-sized woody debris to 20 pools in three streams. We trapped four species of freshwater shrimp (two species of benthic detritivores and two predatory shrimp species) during each of the 4 months following wood additions. An analysis of pool morphology (maximum depth, surface area and volume) provided a useful predictor of shrimp abundances. In general, numbers of shrimps increased with sizes of stream pools. A repeated measures ANOVA demonstrated no effect of woody debris additions on total numbers of shrimp per pool area. Two detritivore species (Atya lanipes, a filter feeder and Xiphocaris elongata, a shredder) decreased in abundance with increased woody debris and there was no statistical relationship between woody debris additions and predators ( Macrobrachium carcinus and M. crenulatum). Small woody debris additions may have altered flow velocities that were important to filter-feeding Atya at the microhabitat scale, although the overall velocities within pools were not altered by wood additions. Lower numbers of Atya and Xiphocaris in two of the three streams may result from the occurrence of two predaceous fishes (American eel and mountain mullet) and more predatory Macrobrachium in these streams. One likely interpretation of the results of this study is that the stream pools in these study reaches had sufficient habitat structure provided by numerous rock crevices (among large rocks and boulders) to provide refuge from predators. Addition of woody debris did not add significantly to the existing structure. These results may not apply to stream channels with sand and gravel substrata where crevices and undercut banks are lacking and where woody debris often plays a major role by providing structure and refuge.

Freshwater shrimps (Crustacea: Decapoda: Caridea) from the Xishuangbanna region of Yunnan Province, southern China

Thirteen species of freshwater shrimps from the Xishuangbanna region of Yunnan Province, southern China, are recognised. Of these, three are atyids: Caridina banna, new species, Caridina menghaiensis, new species and Neocaridina denticulata sinensis (Kemp, 1918a); 10 are palaemonids: Macrobrachium nipponense (De Haan, 1849), M. superbum (Heller, 1862), M. inflatum Liang & Yan, 1985, M. dienbienphuense Dang & Nguyen, 1972, M. pilosum, new species, M. eriocheirum Dai, 1984, M. amplimanus, new species, M. rosenbergii dacqueti (Sunier, 1925), M. yui Holthuis, 1950 and Palaemonetes sinensis (Sollaud, 1911). Morphological descriptions for new species, diagnoses for poorly known species, and systematic discussions for all species are provided. A general discussion with a key for all species is included.

Macrobrachium Denticulatum Sp. N. a New Species of Shrimp From the São Francisco Basin, Northeastern Brazil (Decapoda, Palaemonidae)

[A new species of freshwater shrimp, Macrobrachium denticulatum sp. n., is described and illustrated. It was collected in Sao Francisco Basin, northeastern Brazil., A new species of freshwater shrimp, Macrobrachium denticulatum sp. n., is described and illustrated. It was collected in Sao Francisco Basin, northeastern Brazil.]

中国湖南省産ヌマエビ科ヒメヌマエビ属の1新種

中国湖南省産ヌマエビ科ヒメヌマエビ属の1新種

The First Record of Two Species of Freshwater Shrimps (Decapoda, Caridea, Atyidae) From Iran

The First Record of Two Species of Freshwater Shrimps (Decapoda, Caridea, Atyidae) From Iran

Some Current‐Directed Movements of Macrobrachium Acanthurus (Wiegmann 1836) (Decapoda, Palaemonidae) Under Laboratory Conditions

The larvae of some species of freshwater shrimp of the genus Macrobrachium will develop only in brackish water. The increased incidence of these shrimp within estuaries and in the lower reaches of rivers at certain times of the year suggests that regular down—stream migrations are carried out to facilitate the transport of larvae to a brackish estuarine environment. Current chamber experiments conducted in the laboratory indicated that gravid individuals tend to swim consistently downstream whereas other adult females tend to swim consistently upstream. Other current chamber experiments showed that larval stages, held in brackish water, will drop to a position low in the water column when salinity is reduced (simulating an ebb tide) and revert to swimming higher in the water column when the salinity is increased (simulating a flood tide). These responses are interpreted as a mechanism whereby larvae are prevented from being carried out to sea, thus facilitating their eventual migration upstream to a freshwater environment.