First record of the family Thamnocephalidae (Crustacea: Anostraca) from Southeast Asia and description of a new species of Branchinella

During a two-year investigation of freshwater microcrustaceans in Thailand, an undescribed species of fairy shrimp of the genus Branchinella Sayce, 1903 in the family Thamnocephalidae, was discovered. This is the first record of the genus and the family from Southeast Asia and the second anostracan reported from Thailand. The new species, Branchinella thailandensis n. sp. appears to be morphologically intermediate between B. kugenumaensis (Ishikawa, 1895) from Japan and east China, and B. madurai Raj, 1951 from India and Pakistan. B. thailandensis n. sp. was collected from several temporary ponds in 11 provinces of the northeast and the central Thailand, often co-occurring with Streptocephalus sirindhornae Sanoamuang, Murugan, Weekers & Dumont, 2000.     

The fairy shrimp genus Branchinella Sayce (Crustacea: Anostraca: Thamnocephalidae) in Western Australia,including a description of four new species

The genus Branchinella is diverse in Western Australia, with 18 species, including four new species described here. B. complexidigitata n. sp. is characterized by an intricate frontal appendage, unlike any within the genus. The other three are less remarkable; B. halsei n. sp. is like B. lyrifera, B. kadjikadji n. sp. belongs to the B. affinis group and B. nana n. sp. is similar to B. simplex; similarities are based on frontal appendage and to a lesser extent on the second antennae and penis. Only two species, B. affinis and B. longirostris, are common and widespread; many of the remainder being localized endemics. The high diversity in Western Australia is explained by broad latitudinal range, habitat diversity, and great age and isolation of the landscape.     

Rotifers as food in aquaculture

The rotifer Brachionus plicatilis (O.F. Muller) can be mass cultivated in large quantities and is an important live feed in aquaculture. This rotifer is commonly offered to larvae during the first 7–30 days of exogenous feeding. Variation in prey density affects larval fish feeding rates, rations, activity, evacuation time, growth rates and growth efficiencies. B. plicatilis can be supplied at the food concentrations required for meeting larval metabolic demands and yielding high survival rates. Live food may enhance the digestive processes of larval predators. A large range of genetically distinct B. plicatilis strains with a wide range of body size permit larval rearing of many fish species. Larvae are first fed on a small strain of rotifers, and as larvae increase in size, a larger strain of rotifers is introduced. Rotifers are regarded as living food capsules for transferring nutrients to fish larvae. These nutrients include highly unsaturated fatty acids (mainly 20: 5 n–3 and 22: 6 n–3) essential for survival of marine fish larvae. In addition, rotifers treated with antibiotics may promote higher survival rates. The possibility of preserving live rotifers at low temperatures or through their resting eggs has been investigated.     

Brine shrimps adrift: historical species turnover in Western Mediterranean Artemia (Anostraca)

Biological Invasions - Brine shrimps (Artemia) have undergone geographic range and demographic expansions as a result of their interaction with humans since the beginning of salt harvesting. This...     

Fairy shrimps in distress: a molecular taxonomic review of the diverse fairy shrimp genus Branchinella (Anostraca: Thamnocephalidae) in Australia in the light of ongoing environmental change

Australia, and especially South-Western Australia, is a diversity hotspot for large branchiopod crustaceans. A significant proportion of this diversity is found in the anostracans (Crustacea, Anostraca) and particularly in the diverse genus Branchinella with at least 34 species. Members of this genus are found exclusively in temporary aquatic habitats which are increasingly threatened by secondary salinization and other anthropogenic pressures. The development of adequate conservation strategies is therefore considered a priority. To define conservation units, however, thorough knowledge of the taxonomy and phylogenetic position of extant lineages is essential. We reconstructed a large scale phylogeny of the Australian Branchinella by analyzing the 16S mitochondrial gene of 31 presumed species, complemented with analysis of morphological structures holding taxonomic information. Results revealed the presence of at least three new cryptic species. On the other hand, some Branchinella lineages, surviving in environments subjected to contrasting selection regimes, appeared to be conspecific. This suggests substantial physiological plasticity or important adaptive variation present in some species, potentially enabling them to better cope with environmental change, such as secondary salinization. Overall, these results further illustrate the benefits of combining molecular markers and classic morphological taxonomy and phylogeny to assess biodiversity and define conservation units in cryptic groups.     

Longevity of the freshwater anostracan Streptocephalus mackini (Crustacean: Anostraca) in relation to food (Chlorella vulgaris) concentration

SUMMARY 1. Temporary ponds are inhabited by a variety of invertebrates, of which anostracans are an important group. We studied the lifetables of male and female anostracan Streptocephalus mackini at 3 algal concentrations (0.5 × 10⁶, 1.0 × 10⁶ and 1.5 × 10⁶ cells mL⁻¹).
2. Regardless of sex, S. mackini showed better survivorship at lower food levels. The longest average lifespan observed was 85 ± 2 days for males fed Chlorella at 0.5 × 10⁶ cells mL⁻¹.
3. Both net reproductive rate and generation time decreased with increasing food level. The highest net reproductive rate was about 120 cysts per female. The longest generation time of about 40 days, observed at 0.5 × 10⁶ cells mL⁻¹, was more than three times that at 1.5 × 10⁶ cells mL⁻¹.
4. The rate of population increase ( r ) was nearly the same (0.31 ± 0.06) at high (1.5 × 10⁶ cells mL⁻¹) and intermediate (1.0 × 10⁶ cells mL⁻¹) food levels. The r -value at low food level (0.5 × 10⁶ cells mL⁻¹ of Chlorella ) was 0.20 ± 0.01 per day.     

A new branchipodid genus and species (Crustacea: Branchiopoda: Anostraca) from South Africa

Rhinobranchipus martensi gen. et sp. nov. (Anostraca: Branchipodidae) was collected from a shallow temporary pool in the surroundings of Grahamstown (Cape Province, South Africa) (33^o18'S, 26^o32'E). Rhinobranchipus shares partial fusion of the chitinized basal parts of the male antennae, the so-called clypeus, with other Branchipodidae. The new genus is distinguished from confamilial genera by the morphology of the basal part of the penes. The new species, known from its type locality only, should be considered endangered, if it has not already become extinct as a result of recent modifications of its habitat.     

Galaziella baikalensis, a new genus and species of chirocephalid (Crustacea: Branchiopoda: Anostraca) from Russia and the zoogeography of East Asian Anostraca

Galaziella baikalensis gen. et sp. nov. is described from Olkhon Island, Lake Baikal, Russia. The genus is assigned to the family Chirocephalidae Daday, 1910, on the basis of the following features: the male has two-segmented antenna, its basal segment bearing two leaf-shaped antennal appendages, all thoracopods with two distinctly divided pre-epipodites, and genital segments containing two clearly defined seminal vesicles. Galaziella is well distinguished from other genera of the family by the apical part of the penes, armed with two spiniform processes at each apex, instead of a single spine or toothed plate. Such male genital processes have not yet been found in Chirocephalidae, so that the diagnosis of the family is revised and two sub-families are proposed herein. Up to the present, 10 species belonging to 7 genera, including Galaziella baikalensis, and 5 families of Anostraca – Artemiidae, Branchinectidae, Branchipodidae, Chirocephalidae, and Thamnocephalidae – have been found in East Asia and its adjacent areas, including the Russian Far East, Mongolia, China, Korea, and Japan. The list includes all synonymic taxa. A distribution map and a key to the East Asian species of the family Chirocephalidae are provided. Received: November 22, 1999 / Accepted: May 2, 2000     

Contrary food requirements of the larvae of two Curtonotus (Coleoptera: Carabidae: Amara) species

The larvae of carabids that are granivorous as adults can be granivorous, omnivorous or carnivorous. The differences in larval food preferences of Amara aulica and Amara convexiuscula, two closely related species of the subgenus Curtonotus, were studied. Survival and duration of development of non‐diapausing first and second instar larvae were compared. The third instar larvae were not studied because they go into diapause prior to pupation. The larvae were fed diets consisting of insect larvae (Tenebrio molitor), seeds of Artemisia vulgaris, Tripleurospermum inodorum, Urtica dioica or Cirsium arvense and a mixed diet consisting of insect larvae and seed. Larvae of A. aulica required seeds for successful development, whereas those of A. convexiuscula developed on both an insect diet and seeds of Artemisia. The difference in larval food requirements facilitates the coexistence of these closely related species, which frequently share the same habitat.     

Brycon gouldingi (Teleostei, Characidae): aspects of the embryonic development in a new fish species with aquaculture potential

Brycon gouldingi is an endemic species from Tocantins-Araguaia basin, used as a food source by riverine communities and relevant to aquaculture. Information about the initial morphology of B. gouldingi, a recently described species, is absent. In the present study, we analysed the fertilization and the embryonic development of this species based on light and scanning electron microscopy. After collection of adult specimens in Mortes River - Mato Grosso, Brazil, adaptation to captivity and induced spawning at Buriti Fishculture, Nova Mutum - Mato Grosso, Brazil, in December 2007 and January 2008, samples were collected at pre-defined periods from egg extrusion up to larval hatching, which occurred at 13.9 ± 0.06 h post-fertilization (hpf) in average. At the moment of extrusion, the eggs were slightly ovoid bearing a single micropyle per oocyte with a funnel-shaped micropyle canal and vestibule covered with longitudinal folds, typical of the genus Brycon. The embryonic development of B. gouldingi was characterized by six stages with distinct features: zygote (from fertilization up to formation of egg-cell); cleavage (cell divisions resulting in blastomeres, including the morula phase); blastula (several embryonic cells in a cup shape, without distinction of cell boundaries); gastrula (cell movement); histogenesis/organogenesis (formation of tissues and organs); and hatching (larval chorion rupture). Right after hatching, the larvae presented neither swimming abilities nor visual accuracy, and the digestive trait was undifferentiated. The present study is the first report on biological features of embryogenesis in B. gouldingi, providing relevant information to several approaches, mainly related to taxonomy, ecology, conservation and captive rearing of this new Brycon species.     

Rice bran as a diet for culturing Streptocephalus proboscideus (Crustacea: Anostraca)

We cultured Streptocephalus proboscideus using rice bran as a food source, and compared its growth, mortality, fertility, and cyst hatching with published data on animals fed other food sources. We also analysed the fatty acid profile of animals and cysts. The performance of rice-bran fed shrimp was indistinguishable from that of shrimp fed most other formulated diets, but there are indications that some previously applied diets were either defective in essential fatty acids, or toxic.     

Laboratory experiment to determine the potential of two macroalgae from the Russian Far-East as biofilters for integrated multi-trophic aquaculture (IMTA)

Two local macroalgal species (Undaria pinnatifida and Gracilaria vermiculophylla) were tested in laboratory experiments to determine their nutrient uptake potential and their physiological response to waste water effluents from a mariculture project on bivalve mollusks (mussels). No negative effects on the growth and photosynthesis rates of the algae were detected. High nutrient uptake rates and high nutrient removal efficiency were measured in both tested species. We propose that U. pinnatifida be introduced into IMTA systems during the cold-water season to remove nutrients from cultured animals. The culture of this species can be alternated with that of G. vermiculophylla during warm-water season in order to provide a longer biofiltration period.     

Biometrical key-characters for species separation during ontogenesis in fairy shrimps (Crustacea, Anostraca)

Species identification at the larval stage in Anostraca is a major problem, particularly in field studies when two or more species are co-occuring. Investigation into the possibility of telling larval species apart was performed by means of a biometrical study on wild larvae and juveniles of six fairy shrimp species of the genera Chirocephalus, Branchipus and Tanymastix. A total of ten characters and their relationships with body length were analysed within each of the six developmental stages considered. Most of the variables differed significantly (P<0.001) among the taxa examined. Discriminant analysis allowed individuals to be differentiated according to species and to provided evidence of the existence of a few diagnostic traits of use as key-characters.     

Fatty acid and amino acid composition of two fairy shrimp species (Crustacea,Anostraca) from Italy: Chirocephalus diaphanus and Chirocephalus kerkyrensis

The fairy shrimps Chirocephalus kerkyrensis and C. diaphanus show a high EFA concentration as compared with other marine and freshwater organisms. Based on its 18:3w3 and 20:5w3 FA pattern, C. kerkyrensis is comparable with marine-type Artemia; C. diaphanus, on the contrary, is rich in both these essential fatty acids. Both species contain 22:6w3, a fatty acid seldom found in Artemia.     

Nutritional value of brine shrimp cysts as a factitious food for Orius laevigatus (Heteroptera: Anthocoridae)

Decapsulated cysts of the brine shrimp Artemia franciscana were assessed as a factitious food for rearing the anthocorid predator Orius laevigatus. Developmental and reproductive traits of O. laevigatus reared for a single generation on A. franciscana from three geographical locations or on gamma-irradiated eggs of the Mediterranean flour moth Ephestia kuehniella were compared. There was no effect of diet on nymphal survival but nymphal period on E. kuehniella eggs (12.2 days) was 0.7-1.6 days shorter than on the Artemia diets. The predator developed 0.5-1 day faster on cysts from San Francisco Bay (USA) than on cysts from Great Salt Lake (USA) or Macau (Brazil). Fecundity on brine shrimp cysts from different locations was similar to that on flour moth eggs (142-187 eggs/female). The biochemical composition of decapsulated cysts from San Francisco Bay was compared with that of E. kuehniella eggs. Depending on the type of analysis, Artemia cysts contained higher or similar amounts of protein as compared with E. kuehniella eggs, but amino acid patterns were generally similar. Flour moth eggs were almost three times richer in fatty acids than brine shrimp cysts, with some marked differences in fatty acid profiles. Because nutrient imbalances in a diet may be expressed only after several generations of rearing, the predator was cultured for three consecutive generations on A. franciscana cysts from San Francisco Bay. In the third generation on brine shrimp cysts, nymphs took 18% longer to develop, and adults were shorted-lived and about 60% less fecund than those maintained on E. kuehniella eggs. Brine shrimp cysts may be used as a supplement in the mass production of O. laevigatus but may not be a suitable food for long-term culturing of the predator.     

Respiration of Streptocephalus dichotomus Baird (Crustacea : Anostraca)

Summary The Rate-temperature (R-T) curve for S. dichotomus tends to reach a peak at 30°C in both sexes in all the weight groups. As the temperature increases above 30°C the metabolic rate decreases considerably.The proportionate weight specific rate of oxygen uptake is the same for all sizes.There is no significance in the relationship between oxygen lethal levels and body weight.This work formed part of the thesis submitted for the award of the Degree of Doctor of Philosophy to the University of Madras, in 1970.     

Cultural,food, medicinal uses and potential applications ofMyoporum species (Myoporaceae)

The traditional, current and potential uses ofMyoporum species are documented. Historically, this genus was valued by the Australian Aboriginal people for cultural purposes and as a food plant of minor importance. Medicinal remedies were also acquired from this shrub.Myoporum species were utilised by Aboriginal people in both coastal and Central Australia and throughout the Pacific region. These hardy shrubs are characterised by their drought, fire, frost and grazing tolerances. They have horticultural potential and are good sources of selected phytochemicals.     

Potential for aquatic oligochaetes as live food in commercial aquaculture

Aquatic oligochaetes may potentially become an important constituent in commercial aquaculture as a live food source. Tubifex tubifex, Limnodrilus species, Branchiura sowerbyi and the lumbriculid Lumbriculus variegatus have been economically mass cultured with production rates of 15 kg m^- and population doubling times of 11–42 days reported. Relatively high growth and survival rates of trout, salmon and sturgeon have been achieved in association with the use of this live food source. Benefits stem from advantages with increased appetites and palatability. As well, sanitation and heating requirements in fish hatchery situations may be reduced. Disease transmission must be prevented.     

Nitrogen excretion in Streptocephalus Dichotomus Baird (Crustacea: Anostraca)

Summary The total nitrogen excreted by Streptocephalus dichotomus is 1.5177 mg/g/day for males and 1.3875 mg/g/day for females at 30°C.The main excretory product of S. dichotomus is ammonia (75.3%). The rate of excretion of ammonia increased with increase in temperature up to 30°C and at 33°C it decreased.Analyses of covariance revealed that the F ratios are not significant in the case of rate of total nitrogen excretion between the two sexes at 30°C and in the case of rate of ammonia excretion between the two sexes or when comparison is made within the sexes at the different temperatures between 20° and 30°C.This work formed part of the thesis submitted to the University of Madras for the award of the Degree of Doctor of Philosophy in 1970.     

Genetic characterization of Artemia tibetiana (Crustacea: Anostraca)

The brine shrimp Artemia consists of a number of bisexual species and a large number of parthenogenetic forms, which collectively, inhabit a wide range of hypersaline habitats. A recently described species (A. tibetiana) from a carbonate lake (Lagkor Co) in Tibet at an altitude of 4490 m has been tested with New World (A. franciscana USA, and A. franciscana feral population Vietnam) and Old World species (A. salina, A. urmiana, A. sinica) for cross fertility. These tests show complete infertility between A. tibetiana and A. franciscana . Between A. tibetiana and A. urmiana, A. sinica partial fertility through to F₂ and F₃ generations is evident. Allozyme and RAPD comparison of A. tibetiana with A. franciscana (USA), A. franciscana (Vietnam), A. sinica (Mongolia) and A. urmiana (Iran) show that A. tibetiana is similar to other bisexual species in mean heterozygosity (0.074) but has a somewhat higher proportion of polymorphic loci (40%, similar to that of A. urmiana ). The genetic distance between A. tibetiana and A. franciscana is 0.730, between A. tibetiana and A. urmiana is 0.475 and that between A. tibetiana and A. sinica is 0.114. F_IS estimates for A. tibetiana differ significantly from zero for six loci, mainly because of lack of fit to Hardy-Weinberg expectations. This may suggest that even within the limited area of Lagkor Co there are Genétically distinct populations. © 2002 The Linnean Society of London, Biological Journal of the Linnean Society , 2002, 75 , 333–344.