Acute response of the estuarine crab Eurypanopeus depressus to salinity and desiccation stress (original) (raw)
Related papers
Behavioral Physiology of Four Crab Species in Low Salinity
Biological Bulletin, 1999
Reports focusing on the behavioral responses of crabs to exposure to low salinity have involved choice chamber experiments or quantification of changes in activity. In addition to describing changes in locomotor activity in four species of crabs of differing osmoregulatory ability, the present study describes six behaviors: increased movement of the mouthparts, cleaning of the mouthparts with the chelae, cleaning of the antennae and antennules with the maxillipeds, flicking of the antennae, retraction of the antennules, and extension of the abdomen. Callinectes sapidus and Carcinus maenas are classed as efficient osmoregulators, and in general, showed an increase in these behaviors with decreasing salinity. Cancer magister, a weak regulator, and Libinia emarginata, an osmoconformer, exhibited these behaviors to a lesser degree and became inactive in the lower salinities, tending to adopt an isolation-type response. The differences in behaviors between the species correlated closely with previously reported changes in cardiovascular function and hemolymph flow. These overt reactions are discussed in relation to the osmoregulatory physiology and ecology of each crab species.
Canadian Journal of Zoology
Overfishing of top predators along the western Atlantic coastline has led to a trophic cascade in salt marshes, with increases in herbivorous purple marsh crab (Sesarma reticulatum (Say, 1817)) abundances in North American estuaries leading to overgrazing of cordgrass (Spartina alterniflora Loisel.) and shoreline erosion. To evaluate potential physiological limits on the range of S. reticulatum within an estuary, we evaluated survival and physiological tolerance of S. reticulatum from the Ashepoo–Combhee–Edisto (ACE) River Basin in South Carolina, USA, to combinations of salinity (5‰ and 30‰) and pH (pH 6.6, 7.6, and 8.6) challenges, representative of estuarine extremes. Survival, haemolymph ion concentrations, and gill Na+,K+-ATPase (NKA) and vacuolar-type H+-ATPase (VHA) activity were measured after a 48 h exposure to each experimental condition. Survival was nearly 100% and osmoregulatory control was maintained across estuarine salinity and pH ranges. Sesarma reticulatum appeared...
Aquaculture, 2006
The blue swimmer crab, Portunus pelagicus, is an emerging aquaculture species in the Indo-Pacific. Two experiments were performed to determine the effects of salinity on survival, growth and haemolymph osmolality of early juvenile P. pelagicus crabs. The salinities tested for the first experiment were 10, 15, 25 and 40 ppt, and for the second experiment 5, 20, 30, 35 and 45 ppt. Each salinity experiment was triplicated, with each replicate consisting of 10 stage 4 juveniles. Each experiment lasted 45 days. Mortalities and incidence of "molt death syndrome" were recorded daily, while the intermolt period, carapace length, carapace width and wet weight were measured at each molt. At the end of the experiments the haemolymph osmolality and dry weights were measured.
PeerJ
The invasive Asian shore crab, Hemigrapsus sanguineus, is ubiquitous in the rocky intertidal zone of the western North Atlantic. A likely contributor to this colonization is that H. sanguineus is able to handle a wide range of salinities, and is thus more likely to spread through a greater geographic area of estuaries. This study investigated the salinity effects on this animal by observing survival across a range of salinities, the maintenance of hemolymph osmolality under different salinities, and behavioral preference for and avoidance of salinities. H. sanguineus showed high survival across a broad range of salinities, had little change in hemolymph osmolality over a short-term salinity shock, and behaviorally distinguished between salinities when presented with a choice, under both acclimation salinities of 5 PSU or 35 PSU. Such results suggest H. sanguineus has a hardiness for the rapid changes in salinity that happen in the intertidal zone, yet is capable of physically moving...
2013
The green mussel Perna viridis is a recent invader to Southwest Florida and, though it is currently found only in high salinity areas, concerns abound that it may threaten native oysters. The objective of this study was to compare the responses of P. viridis and the native eastern oyster, Crassostrea virginica, to acute salinity changes by measuring hemolymph osmolality and clearance rate of algal cells over time. The osmolality of hemolymph in vivo and surrounding water were assessed regularly over a one-week period at seven test salinities ranging from 5 to 35. While oysters reached osmotic equilibrium at all salinities within 144 hours, hemolymph of green mussels remained hyperosmotic at salinities ≤ 10. Clearance rates of algae by P. viridis and C. virginica held in static tanks at four salinities (10, 15, 25, and 35) were measured, employing flow cytometry. At salinities of 25 and 35, green mussel clearance rates were approximately double those of oysters. Unlike native oysters, green mussel clearance rates decreased by an order of magnitude at salinities of 10 and 15. Further, at salinities of 10 and 15, P. viridis tended to close their valves. In a specific test of this behavior, 100% of mussels remained open at salinities of 25 and 35. At salinities of 10 and 15, mussels increasingly closed their valves over time, and within 120 hours of exposure all were either closed or dead. The chief concern about P. viridis is that it might compete with native bivalves for food and space. However, our results suggest that this recent invader may be salinity-limited, providing C. virginica with a refuge from competition in estuaries that experience acute periods of low salinity.
Ciencias Marinas, 1992
The oxygen consumption of Callinectes similis was determined under salinity fluctuations. The metabolic rate remained unchanged (P > 0.05) and within a metabolic range of 1.23 to 2.08 mg O2.h–l.g–l D.W., exhibiting a type IV response according to Kinne (1971). Ammonia excretion rose significantly to 0.028 mg N-NH4.h–l.g–l D.W. (P < 0.05) as the salinity decreased from 35 to 24‰; in a salinity range of 18-12-18‰ it remained unchanged at 0.021 mg N-NH4.h–l.g–l D.W. It increased at 26‰to 0.029 mg N-NH4.h–l.g–l D.W. and there was a minimum value of 0.012 mg N-NH4.h–l.g–l D.W. at 35‰. The O:N atomic ratio calculated for C. similis indicates that the crabs were not significantly affected (P > 0.05) by osmotic stress. In high salinities catabolism is based on carbohydrates and in lower salinities on a mixture of lipids and carbohydrates. The osmoregulatory pattern exhibited by C. similis is of an osmoconforming organism, the hemolymph was only slightly hyperosmotic in higher and i...
Journal of Experimental Marine Biology and Ecology, 2008
The specific metabolic rate (SMR) and haemolymph osmolality (HO) of the mud crab Rhithropanopeus harrisii Gould, 1841 from Baltic brackish waters were measured at a habitat salinity of 7 psu (T = 15°C, full air saturation) and after step-wise acclimation to a salinity range of 3-27 psu. Values of SMR at 7 psu varied between 0.40 and 3.89 J g − 1 WW h − 1 (n = 25, wet weight range 0.051-1.142 g) and were significantly ( p b 0.05) related to the specimen's wet weight (WW) according to the power regression SMR = 0.94 WW − 0.41 (R 2 = 0.68). The SMR of females did not differ significantly ( p N 0.05) from those of males. When exposed to higher salinities, the SMR of R. harrisii decreased significantly ( p b 0.05) and reached a minimum value at 23 psu (0.55 ± 0.05 J g − 1 WW h − 1 , n = 6). Mean haemolymph osmolality at 7 psu amounted to 581 ± 26 mOsm kg − 1 (n = 5) and was 2.9 times higher than that of the external medium. R. harrisii hyperosmoregulated its body fluids up to 24 psu (727 mOsm kg − 1 ) at which salinity the isosmotic point was reached.
Journal of The Marine Biological Association of The United Kingdom, 2010
Hemigrapsus crenulatus is an abundant and frequent decapod crustacean inhabiting estuarine environments, where it must tolerate large shifts in salinity. The present study evaluates the effect of salinity (5, 13, 21 and 30 psu) on the adult physiological processes related to the energy balance. The growth potential (SFG) and the respired oxygen:excreted nitrogen ratio were used as indices of stress. Ingestion, excretion and respiration rates showed a significant dependence on salinity, being higher at low salinities. The assimilation efficiency remained constant along the studied salinity gradient. The assimilation and ingestion rates were inversely related with the salinity. Given this scenario, the growth potential remained constant within the studied salinity gradient, as did the oxygen:nitrogen ratio. The results suggest that the increased energy losses at low salinity due to respiration and excretion are compensated by an increment in the ingestion rate, contributing to the success of H. crenulatus in dynamic habitats such as estuaries.