Responses of digestive enzyme profiles in newly-hatched (Zoea I) larvae of the mud crab Scylla serrata to intermittent food availability and food deprivation.

Activities (mU larva) of enzymes critical to digestion were examined to better understand how newly-hatched (Zoea I) larvae of the mud crab Scylla serrata respond to intermittent food availability and food deprivation. Specifically, this study examined the activities of trypsin-like proteases, nonspecific esterases, and α-amylase across three experiments that simulated scenarios in which larvae hatch and experience rearing conditions where food was either: (1) continuously available or unavailable; (2) initially unavailable, but subsequently available; or (3) initially available, but subsequently unavailable. Results showed that food availability exerts a significant influence on enzyme profiles in newly-hatched larvae, with nutritional history influencing their response to food deprivation.

Responses of digestive enzyme profiles to various scenarios of food availability in newly-hatched Stage I phyllosoma larvae of the tropical spiny lobster Panulirus ornatus.

Stage I phyllosoma larvae of the spiny lobster Panulirus ornatus hatch in tropical oceanic waters with limited and variable food resources. To better understand how these larvae cope with food deprivation, this study examined specific (mU mg protein) and total (mU larva) activities of major digestive enzymes (i.e.

Insulin-like androgenic gland hormone 1 (IAG1) regulates sexual differentiation in a hermaphrodite shrimp through feedback to neuroendocrine factors.

Insulin-like androgenic gland hormone (IAG) is regarded as a key sexual differentiation regulator in gonochoristic crustaceans. However, until now the knowledge concerning its functions in hermaphroditic crustaceans is scanty. Herein, we investigated the function of IAG (Lvit-IAG1) in peppermint shrimp Lysmata vittata, a species that possesses protandric simultaneous hermaphroditism (PSH) reproductive system, which is rare among crustaceans.

Roles of gonad-inhibiting hormone in the protandric simultaneous hermaphrodite peppermint shrimp†.

To date, the molecular mechanisms of the unique gonadal development mode known as protandric simultaneous hermaphroditism (PSH) are unclear in crustaceans. In this study, cDNA of a gonad-inhibiting hormone (Lv-GIH1) was isolated from the PSH peppermint shrimp Lysmata vittata, and its expression was exclusively found in the eyestalk ganglion. Real-time quantitative polymerase chain reaction (qRT-PCR) revealed that the expression of Lv-GIH1 increased during gonadal development of the functional male stages but decreased significantly at subsequent simultaneous hermaphroditism stage.

A Possible Role of Crustacean Cardioactive Peptide in Regulating Immune Response in Hepatopancreas of Mud Crab.

Crustacean cardioactive peptide (CCAP), a cyclic amidated non-apeptide, is widely found in arthropods. The functions of CCAP have been revealed to include regulation of heart rate, intestinal peristalsis, molting, and osmotic pressure. However, to date, there has not been any report on the possible involvement of CCAP in immunoregulation in crustaceans.

Embryonic and early larval development of two marine angelfish, and .

Marine angelfish (family: Pomacanthidae) are among the most sought-after fish species in the saltwater aquarium trade. However, there is a lack of information in the literature on their early ontogeny. The objective of this study was to describe the embryonic and early larval development of two dwarf angelfish, the bicolour angelfish, Centropyge bicolor and the coral beauty angelfish, Centropyge bispinosa.

Morphological descriptions of the larval and first juvenile stages of the decorator crab Camposcia retusa (Latreille, 1829) from laboratory-reared material.

The complete larval and first crab stages of the decorator crab Camposcia retusa (Latreille, 1829) are described and illustrated based on laboratory-reared material for the first time. Specimens were obtained from larvae hatched from adult crabs collected from coral reefs of Queensland, Australia. Newly hatched larvae were successfully reared to settlement as the first-stage crabs.

Profiles of calreticulin and Ca2+ concentration under low temperature and salinity stress in the mud crab, Scylla paramamosain.

Calreticulin (CRT) is an important molecular chaperon crucial to survival of organisms under adverse conditions. In this study, the potential roles of CRT in the mud crab, Scylla paramamosain, were investigated. Firstly, SpCRT gene expression was detected in various tissues of S.

Salinity can change the lipid composition of adult Chinese mitten crab after long-term salinity adaptation.

The Chinese mitten crab (Eriocheir sinensis) is an euryhaline crustacean, whose adults migrate downstream to estuaries for reproduction. Lipids are believed to be involved in salinity adaptation during migration. This study investigated the effects of different salinities (0, 6, 12, and 18‰) on the total lipids, neutral lipids, and polar lipids contents, and fatty acid profiles in the gonads, hepatopancreas, and muscles of adult E.

Tamoxifen affects the histology and hepatopancreatic lipid metabolism of swimming crab Portunus trituberculatus.

Tamoxifen (TAM) is an antiestrogenic agent and can enter the aquatic environment in wastewater. It has been reported that TAM can induce hepatic steatosis in vertebrates, however, the effects of TAM exposure on lipid metabolism of hepatopancreas in crustaceans remains unclear. In this study, four TAM concentrations (0, 6.

Effect of estradiol on hepatopancreatic lipid metabolism in the swimming crab, Portunus trituberculatus.

Estradiol is an important sex steroid hormone that involved in regulation of animal lipid metabolism. However, the effect of estradiol on lipid metabolism in swimming crab (Portunus trituberculatus) is unclear. The present study investigated the effect of four concentrations of exogenous estradiol (0, 0.

Ontogenetic development of gonads and external sexual characters of the protandric simultaneous hermaphrodite peppermint shrimp, Lysmata vittata (Caridea: Hippolytidae).

The peppermint shrimp Lysmata vittata (Caridea: Hippolytidae) is a marine caridean shrimp popular in marine aquarium trade. The species is known to display the sexual system of protandric simultaneous hermaphrodite. In this study, based on captive bred specimens, the complete ontogenetic gonad development of L.

A novel crustacean hyperglycemic hormone (CHH) from the mud crab Scylla paramamosain regulating carbohydrate metabolism.

Crustacean hyperglycemic hormone (CHH) plays a crucial role in regulating carbohydrate metabolism in crustaceans. In this study, a new cDNA encoding type I CHH peptide, termed Sp-CHH3, was isolated from the mud crab Scylla paramamosain and its potential functions were investigated. The full length cDNA of Sp-CHH3 was identified as encoding a 127-aa precursor composed of a 27-aa signal peptide, a 23-aa CHH precursor-related peptide and a 75-aa mature peptide with a typical motif of CHH.

Comparative study on the effects of two diatoms as diets on planktonic calanoid and benthic harpacticoid copepods.

Two diatoms, Chaetoceros muelleri and Nitzschia closterium f. minutissima, were used for rearing nauplii to adults of Tigriopus japonicus, Acartia pacifica, and Pseudodiaptomus annandalei at different concentrations. The survival rates to adults and activities of superoxide dismutase (SOD) and glutathione-S-transferase (GST) of the adult copepods were measured.

Physiological Responses and Ovarian Development of Female Chinese Mitten Crab Subjected to Different Salinity Conditions.

Salinity plays a key role affecting ovarian development, osmoregulation and metabolism of female Chinese mitten crab, during reproductive migration. In this study, female after their puberty molt were subjected to four salinities of 0, 6, 12, and 18‰ for 40 days to investigate the salinity effects on their ovarian development as well as a range of important physiological parameters. Elevated salinity accelerated the ovarian development with ovigerous crabs found at salinity treatments of 12 and 18‰ despite no copulation had occurred.

Effects of salinity on gonadal development, osmoregulation and metabolism of adult male Chinese mitten crab, Eriocheir sinensis.

As a catadromous species, salinity is a key parameter that affects gonadal development of Chinese mitten crab Eriocheir sinensis during reproductive migration. It is however unclear the effects of salinity on the gonadal development of male E. sinensis as well as their physiological responses to salinity during reproductive migration.

Toxic effects of polyethylene terephthalate microparticles and Di(2-ethylhexyl)phthalate on the calanoid copepod, Parvocalanus crassirostris.

Large amounts of plastic end up in the oceans every year where they fragment into microplastics over time. During this process, microplastics and their associated plasticizers become available for ingestion by different organisms. This study assessed the effects of microplastics (Polyethylene terephthalate; PET) and one plasticizer (Di(2-ethylhexyl)phthalate; DEHP) on mortality, productivity, population sizes and gene expression of the calanoid copepod Parvocalanus crassirostris.

Domestication as a Novel Approach for Improving the Cultivation of Calanoid Copepods: A Case Study with Parvocalanus crassirostris.

Calanoid copepods are an important food source for most fish larvae. Their role as a natural prey item means that it is important to develop culture technology for copepods to meet the requirements of larvae culture in aquaculture hatcheries. Copepods have been cultured successfully for some time; however, the implications of long-term cultivation or domestication on copepod life history traits have not yet been assessed.

Characterization of CCTα and evaluating its expression in the mud crab Scylla paramamosain when challenged by low temperatures alone and in combination with high and low salinity.

Chaperonin containing the T-complex polypeptide-1 (CCT), which is known to be involved in intracellular assembly and folding of proteins, is a class of chaperonin omnipresent in all forms of life. Previous studies showed that CCT played a vital role in cold hardiness of various animals. In order to understand the response of the polypeptide complex to low temperature challenge and other environmental stresses, a subunit of CCT (CCTα) was cloned from the mud crab Scylla paramamosain by expressed sequence tag (EST) analysis and rapid amplification of cDNA ends (RACE).

Ecdysone receptor in the mud crab Scylla paramamosain: a possible role in promoting ovarian development.

In arthropods, it is known that ecdysteroids regulate molting, limb regeneration, and reproduction through activation of the ecdysone receptor (EcR). However, the ecdysteroid signaling pathway for promotion of ovarian development in crustaceans is still unclear. In this study, three cDNA isoforms of EcR were cloned from the mud crab Scylla paramamosain.

Differential gene expression profile of the calanoid copepod, Pseudodiaptomus annandalei, in response to nickel exposure.

To better understand the underlying mechanisms of reactions of copepods exposed to elevated level of nickel, the suppression subtractive hybridization (SSH) was used to elucidate the response of the copepod Pseudodiaptomus annandalei to nickel exposure at the gene level. P. annandale is one of a few copepod species that can be cultured relatively easy under laboratory condition, and it is considered to be a potential model species for toxicity study.

Survival, osmoregulation and ammonia-N excretion of blue swimmer crab, Portunus pelagicus, juveniles exposed to different ammonia-N and salinity combinations.

Ammonia-N toxicity to early Portunus pelagicus juveniles at different salinities was investigated along with changes to haemolymph osmolality, Na(+), K(+), Ca(2+) and ammonia-N levels, ammonia-N excretion and gill Na(+)/K(+)-ATPase activity. Experimental crabs were acclimated to salinities 15, 30 and 45 per thousand for one week and 25 replicate crabs were subsequently exposed to 0, 20, 40, 60, 80, 100 and 120 mg L(-1) ammonia-N for 96-h, respectively. High ammonia-N concentrations were used to determine LC(50) values while physiological measurements were conducted at lower concentrations.