Distribution and Abundance of Macrobrachium Populations in Palawan

Nothing is known about the population dynamics of Macrobrachium spp. or freshwater decapods in Palawan that hence received little attention to conservation studies that are imperative to establish sustainable management proposals. Thus, this paper provides information on the natural distribution and abundance of Macrobrachium spp. in Palawan to address threats to their survival. Preliminary findings through key informant’s interviews suggest the distribution and abundance of these species in Palawan’s river system. Generally, Macrobrachium spp. are present in all river systems in the province. However, the respondents observed that the population started to decline during the late 1990s attributed to the rampant use of organic pesticides/insecticides for agricultural purposes and intensive quarrying activities stretched along with the river systems in some of the municipalities in Palawan. Results also annotated that the local populations use these animals as food without official regulations, which may be additional pressure on freshwater prawns. The abundance of the Macrobrachium spp. is affected by human interventions and the destruction of their natural habitat and populations. Management measures should be considered from the economic conditions of freshwater prawns for effective management strategy and conservation efforts for future generations.

Freshwater decapods (Crustacea: Decapoda) of Palair Reservoir, Telangana, India

Recent surveys conducted in 2016–2018 from the Palair Reservoir of the Indian state of Telangana resulted in the collection of 153 specimens of freshwater decapods. These specimens are assigned to 10 species: seven prawns in three genera and three families; three crabs in two genera of one family. Among these, four species are recorded here as new records to Telangana: Penaeus semisulcatus De Haan, 1844, Caridina gracilipes De Man, 1892, Barytelphusa guerini (H. Milne Edwards, 1853), and Oziotelphusa sp.

The marbled crayfish (Decapoda: Cambaridae) represents an independent new species

Marbled crayfish are a globally expanding population of parthenogenetically reproducing freshwater decapods. They are closely related to the sexually reproducing slough crayfish, Procambarus fallax, which is native to the southeastern United States. Previous studies have shown that marbled crayfish are morphologically very similar to P. fallax. However, different fitness traits, reproductive incompatibility and substantial genetic differences suggest that the marbled crayfish should be considered an independent species. This article provides its formal description and scientific name, Procambarus virginalis sp. nov.

THE CATALOGUE OF FRESHWATER DECAPODA (DECAPODA: POTAMONIDAE, ASTACIDAE, ATYIDAE) FROM THE REPUBLIC OF MACEDONIA IN THE COLLECTION OF MACEDONIAN MUSEUM OF NATURAL HISTORY

The catalogue summarizes the data found in the collection of freshwater decapods of the Macedonian Museum of Natural History in Skopje, Republic of Macedonia. In the present work we have also critically reviewed the historical data on the occurrence and distribution of representatives of decapods present in the country. The popula-tions of decapods have never been intensively studied in Macedonia, and thus, this catalogue may serve as a valuable source of data for nature conservation and protection of crustaceans and their habitats.

Distribution and abundance of freshwater decapods in an Atlantic rainforest catchment with a dammed future

Variations in physical characteristics along the course of a river influence habitat availability which reflects in species distribution. Knowledge of ecology and diversity of lotic species is important for evaluating how river ecosystems will respond to environmental impacts. Freshwater decapods are a group of high ecological and economic importance, but the knowledge about factors influencing their distribution is scarce in Brazil. We performed a survey of decapods to describe their abundance and distribution as well as to study their relationships with stream physical variables and especially their association with different substrates types. We studied 23 sites located in 15 tributaries of Guapiaçú River, RJ, where we collected decapods in different substrates types and measured a set of physical variables. We found five decapods species, including amphidromous and non-amphidromous shrimps and crabs. Decapods were strongly associated with leaf-litter substrates and their abundance was related to a multivariate axis describing longitudinal changes in stream characteristics. We concluded that decapods occurring in the Guapiaçú catchment inhabit mainly small streams with preserved riparian forests where they find shelter and potential prey of invertebrates. The ongoing project to build a dam on the Guapiaçú River will have negative consequences to migrating shrimps and we strongly recommend that mitigating actions, such the construction of structures to allow the passage of migrating fauna, should be taken.

New data on the taxonomy, ecology, and conservation of the rediscovered Louisea edeaensis (Bott, 1969) (Brachyura: Potamoidea: Potamonautidae), an endangered freshwater crab from Cameroon

The rare and endangered Cameroonian potamonautid freshwater crab Louisea edeaensis (Bott, 1969) was recently rediscovered during a biological inventory of the freshwater decapods of southern Cameroon. The previous record dated back more than 100 years. The new specimens allow an updated diagnosis of the species based on comparisons of important taxonomic characters. Photographs of the carapace, gonopods, third maxillipeds, and chelipeds of the largest adult male specimen from Lake Ossa, Cameroon are provided, as are the first photographs of living specimens. The conservation implications of the new data on habitat, population structure, distribution, and threats for this rare and endangered species are discussed.

Native crab and crayfish co-occurrence: First evidence in Europe

Cases of co-occurrence among freshwater decapods are few. In their European range, the crab