Species Of Fairy Shrimp Research Articles

The Production of Fairy Shrimp as Live Food for Aquatic Animals and Transfer to Farmers

Fairy shrimps are zooplankton, a small crustacean with high nutritional value and carotenoids. Fairy shrimps are aquatic animals that feed on both living and non-living food by filtering. In Thailand, there are 3 species of fairy shrimps, namely Streptocephalus sirindhornae, Branchinella thailandensis, and Streptocephalus siamenesis. The three species of fairy shrimps exhibit distinct characteristics in terms of size, color, and egg morphology. There are 3 types of fairy shrimp culture in Thailand, namely, cement ponds, clay ponds, and hapas, which are adult fairy shrimp cultures. Both living and non-living forms of fairy shrimps are used by freezing. The usage of fairy shrimps come in both living and non-living, frozen forms. Fairy shrimps are fed as food for beautiful aquatic animals such as goldfish, cichlids, etc. They are also used as food pellets to feed aquatic animals such as giant freshwater prawns, Rad tilapia fish, etc. Therefore, it can be concluded that fairy shrimps have a significant potential as a valuable food source for both larval and adult aquatic organisms. Consequently, the widespread dissemination of knowledge about fairy shrimp aquaculture and utilization can greatly enhance their adoption in the aquaculture industry, thereby promoting sustainability.

Biotic interactions vary across species' ranges and are likely conserved through geological time

AbstractAimThe evolutionary interactions between western spadefoot toads (genus Spea) represent a textbook example of character displacement, facilitated by dietary specialization of one Spea species on fairy shrimp (Anostraca) when all three co‐occur. The aim of this study is to understand the covariation between predator (Spea) and prey (Anostraca) range shifts in response to climate change oscillations, and whether biotic interactions can be used to project species distribution models on different time scales when studying species with dietary specialization. Taxon: Amphibia: Spea spp. and Crustacea: Anostraca.LocationNorth America.MethodsUsing multiple modelling techniques, we first estimated the potential distribution of central and western North American fairy shrimp species (Crustacea: Anostraca) and two western spadefoot toad species (Spea bombifrons and Spea multiplicata). We then created a shrimp species richness map by aggregating individual species estimates. Third, we studied the relationship between the probability of spadefoot toad presence and fairy shrimp species richness during the present and Last Glacial Maximum conditions. Finally, we estimated the strength and direction of the co‐occurrence between spadefoot toads and fairy shrimp sampled at the level of entire predicted range and at the regional level (allopatric and sympatric).ResultsFirst, the same abiotic environmental variables shape spadefoot toad and fairy shrimp species' distributions in central and western North America across time. Second, areas of sympatry of Spea bombifrons and Spea multiplicata correspond with dry conditions and higher shrimp richness. Finally, the spatial patterns of predator–prey co‐occurrence are highly variable across geography, forming a spatial mosaic over the species' ranges.Main ConclusionPredator–prey relationships form a spatial mosaic across geography and species ranges. Including biotic interactions into species distribution estimates for organisms with dietary specialization is highly recommended. Biotic interactions can be projected across different time frames for organisms with dietary specialization as they are likely conserved.

Integrating hydrological connectivity and zooplankton composition in Arctic ponds and lakes

Abstract Arctic landscapes are characterised by their numerous ponds and lakes. With increased climate warming and consequent changes in hydrological connectivity, the ecology of many of these waterbodies is expected to change. We sampled 13 ponds and 22 lakes for zooplankton and various limnological and physical environmental variables in the vicinity of Cambridge Bay, Nunavut (69.1169° N, 105.0597° W), with the aim of testing how well the degree of hydrological connectivity explained patterns in species composition and abundance and contributed to crustacean production. Ponds were hydrologically isolated while the lakes were arranged in four lake chains and ranged from the headwaters to highly inter‐connected lakes receiving water from one to 768 upstream lakes. In all sites combined, 77 zooplankton species were found, including 56 rotifers, six copepods, 11 cladocerans, two fairy shrimp species, a mysid, and a tadpole shrimp. We show that the zooplankton communities differed between hydrologically isolated (ponds) and connected (lakes) systems, with 17 species unique to ponds and 20 to lakes. Furthermore, the communities were more similar within lake chains and hence in lakes closer to each other. In ponds, distances between waterbodies had no impact on community similarity. Zooplankton abundance was higher in lakes (255 ind/L) than in ponds (65 ind/L) due to the higher number of rotifers that accounted for nearly 80% of the zooplankton abundance in lakes. In ponds, rotifers, cladocerans, and copepods were equally abundant. In terms of biomass, cladocerans represented 65% of total biomass in all waterbodies except for a chain of deep lakes that had abundant fish communities. In these lakes, cladoceran abundance and biomass were low and probably limited by fish predation. Zooplankton production was higher in ponds (4.6 mgC m−3 day−1) than in lakes (1.7 mgC m−3 day−1), and within lakes was lowest in the chain composed of large lakes (1.3 mgC m−3 day−1). The high production in ponds was closely linked to high zooplankton biomass and further explained by high gross primary production supported by relatively high nutrient concentrations in these shallow systems. Our study emphasises that hydrological connectivity is key to shaping zooplankton communities, although fish presence also appears to affect them. It shows that isolated ponds (that currently account for c83% of all waterbodies on southern Victoria Island) are hotspots of aquatic biological productivity that probably play an essential role in Arctic freshwater landscapes. Finally, our study provides critical baseline information on the current composition of Arctic zooplankton communities important for estimating climate change impacts.

Bacterial communities in Branchinella thailandensis and Streptocephalus sirindhornae.

The fairy shrimp is a freshwater crustacean found in both temporary and permanent freshwaters. In Thailand, fairy shrimp are farmed as live food for ornamental fish. This study aimed to investigate the bacterial compositions in two fairy shrimp species, Branchinella thailandensis and Streptocephalus sirindhornae. Both species were cultured, and total DNA was extracted. The V3-V4 region of the 16S rRNA gene was amplified and sequenced using Illumina Miseq. All data were analyzed by Illumina 16S Metagenomics (version 1.0.1) workflow in Base Space- Illumina. Each read was blasted against the Illumina-curated version of the Greengenes database to determine the operational taxonomic units (OTUs) corresponding to the 16S rRNA gene sequence. The results showed that the Shanon-Weiner diversity index of bacterial compositions in B. thailandensis and S. sirindhornae were 2.135 and 3.122, respectively. The evenness and genus-level richness of the bacterial composition in B. thailandensis were 0.364 and 354 genera, respectively. The dominant bacterium found in B. thailandensis was Nevskia. In S. sirindhornae, the evenness and genus-level richness of the bacterial composition were 0.521 and 400 genera, respectively. Azohydromonas was the dominant bacterium. Our results showed that the compositions and proportions of bacterial communities were specific to each species of fairy shrimp. This study will be useful for further experiments in aquaculture and ecological studies related to symbiotic interaction.

Complete mitochondrial genomes of three fairy shrimps from snowmelt pools in Japan

BackgroundFairy shrimps belong to order Anostraca, class Branchiopoda, subphylum Crustacea, and phylum Arthropoda. Three fairy shrimp species (Eubranchipus uchidai, E. asanumai, and E. hatanakai) that inhabit snowmelt pools are currently known in Japan. Whole mitochondrial genomes are useful genetic information for conducting phylogenetic analyses. Mitochondrial genome sequences for Branchiopoda members are gradually being collated.ResultsSix whole mitochondrial genomes from the three Eubranchipus species are presented here. Eubranchipus species share the anostracan pattern of gene arrangement in their mitochondrial genomes. The mitochondrial genomes of the Eubranchipus species have a higher GC content than those of other anostracans. Accelerated substitution rates in the lineage of Eubranchipus species were observed.ConclusionThis study is the first to obtain whole mitochondrial genomes for Far Eastern Eubranchipus species. We show that the nucleotide sequences of cytochrome oxidase subunit I and the 16S ribosomal RNA of E. asanumai presented in a previous study were nuclear mitochondrial DNA segments. Higher GC contents and accelerated substitution rates are specific characteristics of the mitochondrial genomes of Far Eastern Eubranchipus. The results will be useful for further investigations of the evolution of Anostraca as well as Branchiopoda.

Cover Image

The cover image is based on the Original Article Distinctive genetic signatures of two fairy shrimp species with overlapping ranges in Iberian temporary ponds, by Lopes da Cunha et al. https://doi.org/10.1111/fwb.13782.

Distinctive genetic signatures of two fairy shrimp species with overlapping ranges in Iberian temporary ponds

Abstract Temporary lentic water bodies host biotic assemblages adapted to the transient nature of these freshwater habitats. Fairy shrimps (Crustacea, Branchiopoda, Anostraca) are one of the most important biological components of these unique environments and have a fossil record dating back to the Middle Jurassic (>150 million years). Some anostracan species show a geographically restricted distribution, whereas others are widely dispersed. We aimed to investigate the relationship between different geographic extents and patterns of genetic structure in species of Anostraca. Following this objective, we selected two species with contrasting ranges but overlapping geographic distributions and similar life‐history traits in the study area. We analysed additional information that, from an ecological (e.g. egg‐bank, niche breadth, and pond connectivity) and evolutionary (e.g. crown‐group age of each species) perspective, may explain the obtained phylogeographic patterns. Between 2005 and 2018, we sampled two species of fairy shrimps (309 specimens of Branchipus cortesi and 264 specimens of Tanymastix stagnalis) from 53 temporary ponds of Portugal. We added five other locations from Spain and France to include other European locations for T. stagnalis. Additionally, we also sampled Branchipus schaefferi from two temporary water bodies (Spain and Morocco) to include in the dating analysis. Reconstructed phylogenies based on mitochondrial sequence data indicate the existence of deeply divergent clades with an unequivocal phylogeographic structure in T. stagnalis and shallower divergences in B. cortesi with a less clear geographic correspondence. We found evidence of frequent local and rare long‐distance dispersal events in both species and limited intermediate dispersal, which was more common in B. cortesi. A Bayesian dating analysis using the Branchiopoda fossil record estimated the age of the most recent common ancestors of T. stagnalis and B. cortesi at 32.4 and 12.8 million years, respectively. Haplotype accumulation curves indicated that only a portion of the genetic composition of the species was sampled on each hydroperiod and showed the existence of large, genetically diverse egg banks that remain in the soil. These egg banks represent a genetic reservoir that guarantees the survival of the species because active populations from different hydroperiods may be genetically different and adapt to a changing environment. We hypothesise that the contrasting phylogeographic patterns displayed by the two fairy shrimp species may result from: (1) the earlier age of the most recent common ancestor of T. stagnalis, as older species have more time to accumulate mutations and, thus, are expected to exhibit higher genetic differentiation among populations; (2) slight differences in adult behaviour, life‐history traits and cyst morphologies of T. stagnalis and B. cortesi favouring different animal dispersal vectors with distinct dispersal abilities. Therefore, phylogeographic patterns may be explained by both evolutionary and ecological processes, which operate in different time scales.

Two new species of fairy shrimps (Anostraca: Branchipodidae, Streptocephalidae) from the Northern Cape Province, Republic of South Africa

AbstractWe describe two new species of fairy shrimp from the Northern Cape Province, Republic of South Africa. Both species are from arid inland regions, where little survey work for crustaceans has been conducted. Branchipodopsis transversusn. sp. is separated from congeners by the unique form of the male second antennae, which bear a transverse anterior lobe on the anteromedial projection of the proximal antennomere. Streptocephalus valkyrien. sp. is unique among members of the genus in that its primary diagnostic character is the presence of a pronounced spiniform ‘horn’ on the posterolateral corner of the female’s head. The male antennal appendages are readily diagnosed by the large spines on the ‘palmar; region of the ‘hand.’

Dancing on the top: phylogeography and genetic diversity of high-altitude freshwater fairy shrimps (Branchiopoda, Anostraca) with a focus on the Tibetan Plateau

Fairy shrimp are the most divergent taxon of large branchiopod crustaceans and have a worldwide distribution. Yet the diversity and distribution of fairy shrimps in the “Roof of the World” remain poorly known. Here, based on morphology, we identified three species of fairy shrimp (Branchinecta orientalis, Chirocephalus graziellae and Branchipodopsis affinis), among 14 fairy-shrimp populations from the Tibetan Plateau, China. Their phylogenetic relationships were verified based on mitochondrial DNA sequences (cytochrome c oxidase subunit I gene) and two nuclear markers (18S ribosomal RNA gene and internal transcribed spacer 2). Syntopy of different species of fairy shrimp was observed. Some haplotypes were shared among populations, and sequences from B. affinis exhibited a star-like pattern in haplotype networks, suggesting a recent rapid expansion. Finally, a high genetic diversity of fairy shrimp was detected on the Tibetan Plateau. Obtained results contribute to a better knowledge of the diversity of high-altitude fairy shrimps.

EDNA metabarcoding bioassessment of endangered fairy shrimp (Branchinecta spp.)

Habitat degradation and land-use change severely threaten the survival of fairy shrimp and the vernal pools in which they live. Limiting effective fairy shrimp conservation management efforts is the ability to readily identify species without the capture and sacrifice of individuals for microscopy. Here we demonstrate that eDNA metabarcoding is an effective non-invasive tool for monitoring fairy shrimp. Results from ten Southern California vernal pools comparing eDNA and traditional dip-net methods showed that eDNA metabarcoding with 16S rDNA provides exceptional species-level resolution. Importantly, while the two methods were concordant during early hydroperiods where adults were present, eDNA detected fairy shrimp for up to 2 months after dip-nets failed to detect any adults, expanding the time period for vernal pool monitoring. Together, these results provide resource managers a simple, cost-effective, and non-invasive method for biomonitoring endangered fairy shrimp species.

Three new species of the fairy shrimp Eubranchipus Verill, 1870 (Branchiopoda: Anostraca) from northern Japan and far Eastern Russia

BackgroundSmall crustaceans in the order Anostraca that lack a carapace are commonly referred to as fairy shrimps. Eubranchipus is an Anostracan genus distributed across the Holarctic region. E. uchidai has been recorded only in Japan and has been considered the only species of Eubranchipus in the region.ResultsWe obtained fairy shrimps from three previously unsampled locations (Shiretoko and Chokai in Japan, and Khanka in Russia). Each specimen shares morphological similarities with E. uchidai, but can be discriminated by the second antenna of males and the genital morphology of females. Based on these specimens, we describe three new species of fairy shrimp: Eubranchipus asanumai n. sp. from the banks of the Shiretoko Five Lakes (Japan: Hokkaido), Eubranchipus hatanakai n. sp. from the base of Mt. Chokai (Japan: Yamagata) and Eubranchipus khankanus n. sp. from the banks of Lake Khanka (Russia: Primorsky). Phylogenetic analysis of mitochondrial DNA reveals significant differences from other known Eubranchipus species, including E. uchidai.ConclusionBoth morphological and molecular analyses show that the three new species are similar to E. uchidai but constitute distinct species. Pronounced differences in female morphological features correspond to variability of the amplexus structure previously reported in the genus.

A new genus and species of thamnocephalid fairy shrimp (Branchiopoda: Anostraca) from Argentina (Chubut Province)

ABSTRACT Aeginecta longicauda n. gen., n. sp. is described from material collected from a seasonally astatic aquatic habitat in Argentina. It is only known from the type locality and two male specimens; at this point the female remains unknown. Specific unique gonopod and genital segment features demonstrate that this taxon represents a unique genus within the Thamnocephalidae. Aeginecta n. gen most closely resembles Phallocryptus Biraben, 1951 and Thamnocephalus Packard, 1877. This new genus is easily diagnosed by the compound eye peduncle being extremely short, the frons and anterior surface of antennae II broadened laterally, with an intervening slit through which the compound eye may view the area forward on the animal, and the cercopods are as long as the abdomen. The gonopod proximal portion is bulbous with a transverse cleft, and projects ventrally from the segment. The gonopod distal eversible portion is minute, lamellar, and lies within proximal portion cleft. This is the fifth thamnocephalid genus reported from South America. The Neotropical region has the greatest thamnocephalid generic diversity in the world.

Larval identification of two syntopic species Branchipus schaefferi and Tanymastix stagnalis (Crustacea, Anostraca) sheds light on their pattern of coexistence

In the present study we applied a discriminant function analysis to distinguish two fairy shrimp species, Branchipus schaefferi and Tanymastix stagnalis (Anostraca), co-occurring in Lago dell’Orso in central Italy. Our aim was to obtain information on the pattern of coexistence of these two species to investigate their syntopy since early larval stages. To identify the larvae of the two species we used six discriminant functions, one for each larval stage considered (nauplius, four metanauplius stages and juvenis), and based on morphometric analyses and measurements of different traits (thoracic appendages, body length, length of first antenna, length of head, thorax length and length of furca). The pool was visited at weekly intervals during two time periods for a total of 4 years (1995–1996 and 2000–2001) and physical and chemical variables (water level, water and air temperature, pH and conductivity) were recorded. A total of 1067 specimens were collected, measured and morphometrically identified. B. schaefferi was more abundant and persistent than T. stagnalis. At any stage, T. stagnalis was bigger than B. schaefferi and this difference may justify niche differentiation between coexisting species. Difference in size might be linked to difference in life-span as B. schaefferi reproduced earlier and at a smaller size than T. stagnalis. When the hydroperiod is short, B. schaefferi might be the only species to produce resting eggs in time for reproduction. On the other hand, T. stagnalis may have an advantage in the longest hydroperiods. In an ephemeral seasonal pond such as Lago dell’Orso, coexistence can be fostered and competitive exclusion can be prevented as a result of seasonal environmental changes.

Acute sensitivity of the vernal pool fairy shrimp, Branchinecta lynchi (Anostraca; Branchinectidae), and surrogate species to 10 chemicals.

Vernal pool fairy shrimp, Branchinecta lynchi, (Branchiopoda; Anostraca) and other fairy shrimp species have been listed as threatened or endangered under the US Endangered Species Act. Because few data exist about the sensitivity of Branchinecta spp. to toxic effects of contaminants, it is difficult to determine whether they are adequately protected by water quality criteria. A series of acute (24-h) lethality/immobilization tests was conducted with 3 species of fairy shrimp (B. lynchi, Branchinecta lindahli, and Thamnocephalus platyurus) and 10 chemicals with varying modes of toxic action: ammonia, potassium, chloride, sulfate, chromium(VI), copper, nickel, zinc, alachlor, and metolachlor. The same chemicals were tested in 48-h tests with other branchiopods (the cladocerans Daphnia magna and Ceriodaphnia dubia) and an amphipod (Hyalella azteca), and in 96-h tests with snails (Physa gyrina and Lymnaea stagnalis). Median effect concentrations (EC50s) for B. lynchi were strongly correlated (r2 = 0.975) with EC50s for the commercially available fairy shrimp species T. platyurus for most chemicals tested. Comparison of EC50s for fairy shrimp and EC50s for invertebrate taxa tested concurrently and with other published toxicity data indicated that fairy shrimp were relatively sensitive to potassium and several trace metals compared with other invertebrate taxa, although cladocerans, amphipods, and mussels had similar broad toxicant sensitivity. Interspecies correlation estimation models for predicting toxicity to fairy shrimp from surrogate species indicated that models with cladocerans and freshwater mussels as surrogates produced the best predictions of the sensitivity of fairy shrimp to contaminants. The results of these studies indicate that fairy shrimp are relatively sensitive to a range of toxicants, but Endangered Species Act-listed fairy shrimp of the genus Branchinecta were not consistently more sensitive than other fairy shrimp taxa. Environ Toxicol Chem 2017;36:797-806. Published 2016 Wiley Periodicals Inc. on behalf of SETAC. This article is a US government work and, as such, is in the public domain in the United States of America.

Null models for understanding fairy shrimp habitats

The Chilean fairy shrimp species are represented by the Branchinecta genus, which are poorly described, and mainly occur in shallow ephemeral pools in the Atacama Desert of northern Chile and the Southern Chilean Patagonian plains. The aim of the present study was to perform an initial ecological characterization of Branchinecta habitats and its associated communities in the Chilean Southern Patagonian plains (45-53°S) using null models (co-occurrence, niche sharing and size overlap). The results of the co-occurrence analysis revealed that the species’ associations are structured, meaning that at different kinds of Branchinecta habitats, the associated species are different. I did not find niche sharing, which means interspecific competition is absent. Finally the size overlap analysis revealed structured patterns, which are probably due to environmental homogeneity or colonization extinction processes. The habitats studied are shallow ephemeral pools, with extreme environmental conditions, where continuous local colonization and extinction processes probably occur, which would explain the marked Branchinecta species endemism.

Linderiella jebalae sp. nov. (Crustacea: Branchiopoda: Anostraca), a new species from the Rif mountains (northern Morocco).

A new species of fairy shrimp, Linderiella jebalae sp. nov., was found in temporary ponds located in the Rif region of northern Morocco. Morphological characters of females, such as the basal long warty outgrowth of the antennae, the highly developed cuticular papillae in the second genital segment, and the presence of a keel-shaped process directed posteriorly in dorsal side of the brood pouch, clearly distinguish this species from the others of the genus. In the case of males, the basiomedial antennal outgrowth and the distal segment of the antenna are diagnostic features for the species. Cyst ornamentation, characterized by thick, blunt and sometimes truncated spines, also separate this species. This is the fourth known Palaearctic Linderiella species, all of them described recently (from 1980s onwards) and located in a restricted area, from south-eastern France to Iberian Peninsula and Morocco.

Thamnocephalus chacosaltensis, a new species of Anostraca (Crustacea: Branchiopoda) from Salta province (Argentina).

Thamnocephalus chacosaltensis, a new species of fairy shrimp, was found in a temporary turbid pond in the Rivadavia Department, Salta province, Argentina (24º13'19.3''S; 62º 52'14.3''W), belonging to the Chaco salteño. The males present a well developed frontal appendage. Their First (FB) and Third (TB) branches show features diagnostic for the species. FB shows three sub-branches; the most proximal one is coiled, lacks spines all along, gradually thins in distal direction and flattens in the distal half; distally, the flattened portion is folded and ends blunt, bearing a small spine at the tip. TB is a broad-based triangular, thin, much flattened and folded outgrowth, with a small spine at the apex. Male genital and abdominal segments lack medio-ventral spines near their posterior margins. Comparisons with the other species of the genus are established.

A new Dendrocephalus (Crustacea, Anostraca, Thamnocephalidae) from Rio Grande do Sul State, Brazil

Dendrocephalus riograndensis n. sp., a new species of fairy shrimp, is described from a single temporary pool in Santa Vitoria do Palmar, Rio Grande do Sul, Brazil. Males are readily separated from all other DendrocephalusDaday, 1908species by the form of the frontal appendage and the form of the first thoracopods. This new species is most similar to Dendrocephalus goiasensis Rabet & Thiery, 1996 and could be confused with this species. This new species appears to be endemic to Rio Grande do Sul.

Combined effect of temperature and salinity on hatching characteristics of three fairy shrimp species (Crustacea: Anostraca)

The combined effects of temperature and salinity on hatching performance of three anostracan species, Phallocryptus spinosa, Branchinecta orientalis and Streptocephalus torvicornis from East and West Azerbaijan, Iran, were studied. The cysts were kept for 10 days at seven different temperatures (12, 15, 18, 21, 24, 27 and 30°C) and four salinity conditions (0, 5, 10, and 15 gL ‐1 ), and the effects of the resulting 28 experimental conditions on hatching patterns (duration of pre-hatching period, hatching percentage at first day of hatching, cumulative hatching success) were examined. Results were tested by ANOVA and multiple regression was applied to generate contour models by polynomial equation. The hatching performance in all species was significantly affected by temperature and salinity. Based on contour plot analysis, maximum hatching for P. spinosa, B. orientalis and S. torvicornis cysts was registered at temperatures 19-25oC, 18-23oC and 16-20oC, respectively, within the same salinity range of 0-1 gL ‐1 . The highest cumulative hatching success among the species was observed in P. spinosa at the combination of 24°C and 0gL ‐1 (88. 98%). No hatching was observed for eggs of S. torvicornis and B. orientalis incubated at lower ( 27oC) temperature, respectively. The pre-hatching period was prolonged with increase in salinity and decrease in temperature and was highest in P. spinosa (7.7 days at 12°C and 15 gL ‐1 salinity). High hatching success was observed over wide ranges of temperature and salinity in P. spinosa eggs which demonstrates one of the possible mechanisms responsible for the wide distribution of this species.

Current knowledge of the South East Asian large branchiopod Crustacea (Anostraca, Notostraca, Laevicaudata, Spinicaudata, Cyclestherida)

The large branchiopod crustaceans (fairy shrimp, tadpole shrimp and clam shrimp) of South East (SE) Asia have only recently been examined with scientific vigor. Although more than 70 species have been reported for Asia and Indonesia, only six native taxa and one introduced species are known from SE Asia. The majority of records are from Thailand, with fewer than three records each from Laos, Myanmar, Malaysia, Cambodia, Vietnam, and Singapore. Eleven genera reported from adjacent regions may potentially occur in SE Asia. Spinicaudatan clam shrimp have been collected from Thailand and Cambodia, but have not been identified beyond genus. Four of the five native fairy shrimp species are endemic to SE Asia. The limited distributions of these few taxa suggest that this region has a distinct branchiopod fauna. In addition, we present new species and records of clam shrimp from Thailand. Future survey efforts will undoubtedly reveal additional taxa.