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PubMed2004

Mysid crustaceans as potential test organisms for the evaluation of environmental endocrine disruption: a review.

Anthropogenic chemicals that disrupt the hormonal systems (endocrine disruptors) of wildlife species recently have become a widely investigated and politically charged issue. Invertebrates account for roughly 95% of all animals, yet surprisingly little effort has been made to understand their value in signaling potential environmental endocrine disruption. This omission largely can be attributed to the high diversity of invertebrates and the shortage of fundamental knowledge of their endocrine systems. Insects and crustaceans are exceptions and, as such, appear to be excellent candidates for evaluating the environmental consequences of chemically induced endocrine disruption. Mysid shrimp (Crustacea: Mysidacea) may serve as a viable surrogate for many crustaceans and have been put forward as suitable test organisms for the evaluation of endocrine disruption by several researchers and regulatory bodies (e.g., the U.S. Environmental Protection Agency). Despite the long-standing use of mysids in toxicity testing, little information exists on their endocrinology, and few studies have focused on the potential of these animals for evaluating the effects of hormone-disrupting compounds. Therefore, the question remains as to whether the current standardized mysid endpoints can be used or adapted to detect endocrine disruption, or if new procedures must be developed, specifically directed at evaluating hormone-regulated endpoints in these animals. This review summarizes the ecological importance of mysids in estuarine and marine ecosystems, their use in toxicity testing and environmental monitoring, and their endocrinology and important hormone-regulated processes to highlight their potential use in assessing environmental endocrine disruption.

Animals↗
PubMed2002

Isopod gut microflora parameters as endpoints in toxicity studies.

Terrestrial isopods Porcellio scaber (Crustacea) were fed for five weeks on food contaminated by 250, 500, or 1,000 microg of Cd/g or for 10 d on diets with 50 or 250 microg Cd/g food. In both experiments, fecal production rate and colony forming units (CFUs) in the guts were determined. In addition, at the end of 10 d, each distinct colony morphotype obtained in gut samples was purified and characterized. Isolates were separated into 25 groups based on morphological and biochemical characteristics. These bacterial groups were used as units for calculating Shannon equitability indices (J) for each gut. The relative frequencies of the 25 bacterial units were determined in both cadmium groups (50 or 250 microg Cd/g food) and in the control. Cadmium-induced perturbations observed in the gut microbial communities were (1) increased number of morphologically distinct bacterial isolates in the group fed low-cadmium-dosed food (50 microg Cd/g) and reduced number of morphologically distinct bacterial isolates in the group fed high-cadmium-dosed food (250 microg Cd/g) compared with the control, (2) increased or decreased relative frequencies of almost all 25 bacterial units provoked by cadmium-contaminated food, (3) time-dependent increased numbers of gut CFUs in cadmium-fed animals (dose dependence was not observed), and (4) significant changes in community structure described by Shannon equitability indices at lower levels of food contamination (50 microg Cd/g) only. Gut microflora parameters are proposed as additional endpoints in the standardized single-species toxicity test with the terrestrial isopod P. scaber as a means of increasing the ecological relevance of the results.

Administration, Oral↗
PubMed2003

Molecular cloning and expression analysis of cDNAs encoding androgenic gland hormone precursors from two porcellionidae species, Porcellio scaber and P. dilatatus.

Male sexual characteristics in Crustacea are induced by androgenic gland hormone (AGH), which is produced by the male-specific androgenic gland. Recently, AGH in the terrestrial isopod Armadillidium vulgare was characterized and its cDNA cloned, the first example in which the structure of AGH was elucidated. We report here the molecular cloning of cDNAs encoding AGH precursors from two additional terrestrial isopods, Porcellio scaber and P. dilatatus. cDNA fragments encoding Porcellio scaber AGH (Pos-AGH) and P. dilatatus AGH (Pod-AGH) were amplified by RT-PCR using degenerate oligonucleotide primers designed based on the amino acid sequence of A. vulgare AGH (Arv-AGH). Subsequently, full length cDNAs were obtained by 5'- and 3'-RACE. Both AGH precursors consisted of a signal peptide, B chain, C peptide and A chain, and exhibited the same organization as that of Arv-AGH. The amino acid sequences of the A and B chains, which comprise mature AGH peptide, were highly conserved among the three species, while that of the C peptide showed only low sequence similarity. In Northern blot analysis, each cDNA fragment used as a probe specifically hybridized with a single band (0.75 kb) in mRNA extracted from whole male reproductive organs. In analysis of the tissue-specific gene expression of these two AGHs by RT-PCR, it was revealed that both AGH transcripts were detected only in cDNA synthesized using total RNA from the testis carrying the androgenic glands, but not in that from testis only, seminal vesicle, vas deferens, or hepatopancreas.

Amino Acid Sequence↗
PubMedDate not supplied

Macroinvertebrate biomonitoring in intermittent coastal plain streams impacted by animal agriculture.

Little attention has been given to the ecology of intermittent coastal plain streams in the southeastern United States, and it is not known whether available macroinvertebrate biomonitoring methods reliably detect degradation in these streams. This study compared differences in biomonitoring metrics between reference and agricultural streams, and between the flow period (January-April) and the intermittent flow period (May-December). Percentages of crustaceans, isopods, and Ephemeroptera-Plecoptera-Trichoptera (EPT) were significantly higher at the reference site than the two most impacted sites during the flow period, probably resulting from the abundance of leaf litter and lower temperatures. During this same period, the agriculturally impacted sites had a significantly higher percentage of dipterans--a group that thrives in the silty, nutrient-rich waters. Four metrics (percent Crustacea, Isopoda, Diptera, and EPT) had no overlap between values for the most impacted and the least impacted sites during the flow period, but no metrics were able to detect more discrete differences among sites. Sites were physically and biologically similar during the intermittent period when natural stresses (i.e., stagnant water, high temperatures, low dissolved oxygen) were high, with many metrics, such as percentages of dominant family, burrowers, chironomids, and dipterans becoming similar at all sites. Our findings indicate that development of a better understanding of invertebrate fauna in reference conditions and of the natural variation in intermittent streams is necessary to develop effective biomonitoring programs for these systems.

Agriculture↗
PubMed1991

An H3-H4 histone gene pair in the marine copepod Tigriopus californicus, contains an intergenic dyad symmetry element.

Histone genes are one of the most widely studied multigene families in eucaryotes. Over 200 histone genes have been sequenced, primarily in vertebrates, echinoderms, fungi and plants. We present here the structure and genomic orientation of an H3-H4 histone gene pair from the marine copepod, Tigriopus californicus. These histone gene sequences are the first to be determined for the class Crustacea and among the first to be determined for protostomes. The H4 and H3 genes in Tigriopus are shown to be adjacent, to have opposite polarity, and to contain a 26 bp region of dyad symmetry centrally located within the spacer region between the two genes. A similarly located dyad element has been found in yeast which contributes to the coordinated cell cycle control of the adjacent histone genes. The Tigriopus H3-H4 histone gene pair is clustered with one H2A and two H2B histone genes on a 15 kb genomic Bam H1 fragment. The H4 gene sequence predicts an H4 protein with an unusual serine to threonine substitution at the amino terminal residue. The H3 gene sequence predicts an H3 protein which is identical to the vertebrate H3.2 histone.

Amino Acid Sequence↗
PubMed2005

A review of the parasitic dinoflagellates Hematodinium species and Hematodinium-like infections in marine crustaceans.

Parasitic dinoflagellates in the genus Hematodinium are important parasites of marine Crustacea. Outbreaks of these parasites have damaged commercial stocks of Norway lobster Nephrops norvegicus, snow crab Chionoecetes opilio, Tanner crab C. bairdi, American blue crab Callinectes sapidus, and velvet swimming crab Necora puber. Species of Hematodinium can reach high enough levels to regulate their host populations, but mortalities are also centred on the unfished juveniles and females, hosts not normally sampled by fisheries; hence impacts are often underreported. Seasonal prevalences of up to 85 % occur annually in many host populations; in effect, these parasites form cryptic blooms in the water column with crabs and other crustaceans at risk of disease. We review the biology and ecology of Hematodinium spp. infections in crustaceans. Included is a comparison of the different infections, a synthesis of what is known, and an attempt to highlight fruitful areas for continued research.

Animals↗
PubMed2000

Toxicity of a Neem (Azadirachta indica) insecticide to certain aquatic organisms.

Neem based insecticides are likely to show a large increase in use in the near future. In the present work, the toxicity of a neem insecticide, Neem-Azal-T/S, was tested against the mosquito larvae, as well as against certain non target organisms occurring in a polluted pond and a shallow stream, located in a cultivated area in Giza, Egypt. Samples of water containing the experimental animals were collected from this area, and toxicity tests were conducted in the laboratory by exposing them to a series of concentrations of the botanical insecticide, using the water of the pond and stream at room temperature (28-31 degrees C). The compound was more or less toxic to all the tested species. The LC50S and mortality rates were determined. The order of tolerance of the organisms to different concentrations of the insecticide was: larvae of Bufo regularis (Amphibia) > Aedes caspius. (Insecta) > Gambusia affinis (Poeciliidae) > Cyclops sp. > Daphnia magna (Crustacea). At a concentration of 20 ppm, all the tadpoles died within 9 days, while all other individuals died within 5 to 8 days after exposure to a concentration of 10 ppm of Neem Azal insecticide.

Aedes↗
PubMedDate not supplied

[Chemical interactions between planktonic crustaceans].

Three levels of chemical communications involved plankton Crustacea are considered: 1) Influence of zooplankton excretion on phytoplankton; 2) Influence of zooplankton excretion on the individuals of the same or other species of the same trophic level; 3) Influence of chemical cues released by predatory zooplankton and fish on herbivorous zooplankton. The data on the influence of excreted cues on some physiological (growth, reproduction, feeding, etc.) and behavioural (vertical and horizontal migrations) characters of planktonic crustaceans are presented. Ecological role and chemistry cues responsible for the interactions of different trophic levels can be different. It is considered that chemical communications in aquatic ecosystems can be provided with: 1) Species-specific cues that strictly influence particular biological functions (communication system of feromone type); 2) Non-specific cues that strictly influence particular functions (system of regulator, that act at the whole ecosystem as the hormonal system of an organism). 3) Non-specific substances with broad (non-specidic) influence--toxic substances of "biocondition substances" according to classification of Novikov and Kharlamova (2000).

Animal Communication↗
PubMed1992

[Characterization of secondary vitellin in the crustacean Brachyura Carcinus maenas].

The secondary vitellin was chromatographically purified and characterized in the crab, Carcinus maenas. It was a lipoglycoprotein of molecular weight 500,000. After dissociation, we observed two major sub units (82,000 and 72,000, respectively), and many lighter minor fractions. These results are compared with those described for some other Crustacea.

Animals↗
PubMed2006

From more to fewer? Testing an allegedly pervasive trend in the evolution of morphological structure.

While evolutionary trends have long received much attention and have been widely disputed, new methods are now allowing the testing of directional hypotheses with increased rigor. Here, we test a general hypothesis about the way many kinds of discrete characters are thought to evolve, termed oligomerization. This is the tendency for serial structures (such as arthropod body and appendage segments) or armature (such as spines) to evolve primarily through loss and fusion. Focusing on the Crustacea, we use maximum likelihood methods to test for directional evolution in a large sample (> 500) of discrete traits, analyzed against molecular-based phylogenies. We find evidence for a significant trend toward trait loss, in accordance with the reduction principle. However, this trend is far from ubiquitous, with many characters exhibiting a reconstructed bias toward gains. These results suggest that caution must be used before drawing conclusions about which taxa are "primitive" or about the directionality of morphological shifts in the absence of phylogenetic analysis. Nevertheless, oligomerization-as a trend rather than a law-may be an important process that influences evolutionary trajectories from both morphological and functional perspectives.

Animals↗
PubMed2006

[Metazoan parasites of carp (Cyprinus carpio Linnaeus, 1758) and vimba (Vimba vimba Linnaeus, 1758) in the Sapanca lake].

In this study metazoan parasites of carp (Cyprinus carpio Linnaeus, 1758) and vimba (Vimba vimba Linnaeus, 1758) in the Lake Sapanca were investigated from January 2004 to December 2004. A total of 31 fish were investigated. Out of the 16 C. carpio, 13 were infected by parasites and of the 15 V. vimba, 11. The parasites found in C. carpio were: Dactylogyrus phoxini (Malevitskaya, 1949), Dactylogyrus extensus (Müller, Van Cleave, 1932), Gyrodactylus sp. Monogenoidea, Caryophyllaeus laticeps (Pallas, 1781), Bothriocephalus acheilognathi (Rud, 1808) Cestoidea, Diplostomum sp. Trematoda, Glochidium sp. Bivalvia. The parasites found in V. vimba were: Dactylogyrus sphyrna (Linstow, 1878), Dactylogyrus cornu (Linstow, 1878), Dactylogyrus cornoides (Gläser et Gussev, 1971) Monogenoidea, Aspidogaster limacoides (Dies., 1835), Posthodiplostomum cuticola (Nordmann, 1832), Tylodelphys clavata (Nordmann, 1832), Diplostomum sp., Tetracotyle sp. (Linstow, 1856) Trematoda, Neoechinorhynchus rutili (Müller, 1780) Acanthocephala, Glochidium sp. Bivalvia, Argulus foliaceus (Linnaeus, 1758), Ergasilus sieboldi (Nordmann, 1832) Crustacea. The parasites were investigated according to the place they were found in the host, prevalence and intensity of infections in the fish. Also the average intensity of the infection as well as the minimum and maximum intensities was estimated.

Animals↗
PubMed1991

Phylogenetic analysis of Alloglossidium Simer, 1929 (Digenea: Plagiorchiiformes: Macroderoididae) with discussion of the origin of truncated life cycle patterns in the genus.

Alloglossidium comprises 9 species of North American plagiorchiiform digeneans using ictalurid catfish, freshwater crustacea, and hirudinid leeches as definitive hosts. Two hypotheses about the evolution of this array of definitive hosts were examined using phylogenetic systematic analysis. Two most parsimonious trees, based on 15 homologous series derived from morphological data, each indicated the 2 species utilizing ictalurid catfish definitive hosts are basal members of the group, whereas the 2 species using freshwater crayfish definitive hosts and the 5 utilizing leech definitive hosts each comprise relatively derived monophyletic sister groups. The results suggest that species using crustaceans as definitive hosts are derived by life cycle truncation, whereas those using leeches as definitive hosts appear to be derived through a switch from crustaceans to leeches.

Animals↗
PubMed1991

The myocardial ultrastructure in three amphipod species from Lake Baikal.

The heart ultrastructure of several crustacean species has previously been studied. Special interest has been paid to the development of the membrane systems of the cardiac myofiber relative to the different sarcomeric levels. This system seems to give phylogenetic information, but there still remains some uncertainty concerning its reliability. Is it affected by the size of the species, or is there any geographical variation within the different crustacean orders? The aim of this study is to compare the heart ultrastructure of some large amphipids from Lake Baikal(Acanthogammarus albus, Parapallasea puzylli and Poekilogammarus sukaczewi) with smaller amphipods from Europe and Northern America. It is shown that species size and geographical isolation do not seem to affect the membrane systems qualitatively. The isolation and adaptive radiation of the amphipods in Lake Baikal have not brought about any significant changes in the heart ultrastructure which separates them from other amphipod species. These findings support the use of cardiac membrane systems as a phylogenetic tool in the classification of Crustacea.

Actin Cytoskeleton↗
PubMed1975

An optimum pH for the demonstration of chitin in Periplanata americana using Lugol's iodine.

Modification of chitosan test of Campbell is suggested with a controlled procedure involving heating with saturated potassium hydroxide at 160 degrees C for a period of 45 min and subsequent washing of the deacetylated chitin in running water and application of Lugol's iodine solution (1:2:300, w/w/v) at a pH range of 1.4 to 4.0, thus replacing the use of dilute sulphuric acid. Consistent results were obtained not only with the cuticle of Periplanata americana but also with the cuticle of Emerita asiatica (crustacea).

Alkalies↗
PubMed1988

Cross-reactivity of foods--mechanisms and clinical significance.

We have been most fortunate to witness advances in techniques related to the field of allergy. The development and implementation of RAST, RAST inhibition, crossed immunoelectrophoresis, and CRIE have allowed us to determine what food moieties have the potential to be allergenic. Furthermore, using the above techniques, it has become possible to delineate whether allergenic moieties in particular food stuffs share their allergenic determinants with other food materials. Despite these advances, it is difficult to make definite statements concerning clinically significant cross-reactivity among nuts, legumes, and crustacea. There is still, obviously, a role for the use of open and double-blind food challenges, as demonstrated by the peanut oil, soybean oil, and sunflower oil studies. Although food challenges, in situations where anaphylaxis is a possibility, should only be done under controlled circumstances and under the guidance of a well-defined protocol, this technique should remain available to further study cross-reactivity among foods. At the present time, the following conclusions concerning cross-reactivity among foods may be entertained. (1) Cross-reactivity among foods from different food groups is extremely rare. (2) Individuals having IgE-mediated reactions to legume proteins, for example peanut and soybean, do not respond to the corresponding oil derived from those substances. (3) Cross-reactivity among legumes may occur, but in vitro studies defining common allergenic determinants among these food substances cannot be automatically interpreted as reflecting in vivo cross-reactivity. Furthermore, very limited attempts at open and double-blind challenges in specific patients have not confirmed cross-reactivity in peanut-sensitive individuals to other legumes.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1985

Osmotic control in marine animals.

The sea is the home of two types of animal; primary marine inhabitants of wholly marine ancestry (mainly invertebrates) and secondary marine inhabitants (mainly fish and higher vertebrates) which have had a freshwater or terrestrial phase in their evolutionary history. The former have blood osmolarities close to that of seawater, and only encounter osmotic problems at the sea's margins (e.g. intertidal zones, lagoons, estuaries) where salinities are different from the open sea; the latter have low blood concentrations and potentially have problems of salt loading and water loss in seawater. Most primary marine inhabitants are stenohaline, live in the open sea and encounter no osmotic stress, and can tolerate little change in external salinity. The bulk of their euryhaline relatives living in the more demanding environments of littoral zones and estuaries rely heavily upon behavioural osmotic control. Sessile animals employ isolation responses (burrowing, shell valve closure etc.) when external salinities are stressful; mobile species have been little studied, but some are known to avoid deleterious salinities or choose optimum concentrations. The existence of predictive and reactive categories of behavioural osmotic control in mobile animals is suggested. Intracellular osmotic regulation by changes in the size of the pool of non-essential amino acids is the basis of much penetration of brackish/hypersaline water by primary marine inhabitants; however, it is doubtful whether changes in amino acid concentration are rapid enough to prevent cellular swelling/shrinkage in animals exposed to short-term salinity fluctuations (e.g. in estuaries, splash-zone pools). Extracellular osmoregulation is characteristic of fish, many euryhaline crustacea and a few representatives of other groups. It depends primarily on salt pumps (located usually at gut and/or gill) but low integumentary permeabilities to salt and water are equally essential. The permeability of teleost eggs to salt and water is given special consideration because of their hypo-osmotic state and apparent absence of osmoregulatory structures. In elasmobranchs and coelocanths the problems of salt loading and water loss have effectively been met by separate mechanisms. Osmotic water loss is opposed by high blood concentrations of urea (maintained by renal reabsorption and low branchial permeability) which result in a total blood osmolarity rather higher than that of the external medium.(ABSTRACT TRUNCATED AT 400 WORDS)

Adaptation, Physiological↗
PubMed1988

[The parasite fauna of Stizostedion lucioperca from the bay waters of the Baltic coast of East Germany].

In pike-perches 20 species of parasites were stated: Protozoa (1), Monogenea (1), Cestoda (2), Trematoda (8), Nematoda (3), Acanthocephala (2), Hirudinea (1) and Crustacea (2). The high extent and intensity of parasitation Bunodera luciopercae in pike-perches of the Oder Bay are striking, a fact which may inhibit their growth and development. Parasitological investigation (infestation of pike-perch with Brachyphallus crenatus and Anisakis spec. larv.) has proved that about 75% of pike-perch migrate between the areas of the Peenestrom and the Bay of Greifswald. The high extent of Achtheres percarum infestation of fish causes serious damage to the gill filaments in a number of cases. The studies carried out to date have shown that parasite infestation of pike-perch has no negative effect on its edibility.

Acanthocephala↗