Effects of adult salinity acclimation on larval survival and early development of Strongylocentrotus droebachiensis and Strongylocentrotus pallidus (Echinodermata: Echinoidea)

1994 ◽  
Vol 72 (11) ◽  
pp. 1931-1939 ◽  
Author(s):  
Richard A. Roller ◽  
William B. Stickle
Keyword(s):  
Sea Water ◽  
Sea Urchins ◽  
Subsequent Development ◽  
Larval Survival ◽  
Strongylocentrotus Droebachiensis ◽  
Salinity Acclimation ◽  
Percent Survival ◽  
Low Salinity ◽  
Development Rates ◽  
Survival And Development

Larval survival and development rates of Strongylocentrotus droebachiensis and Strongylocentrotus pallidus were determined as a function of salinity in two experiments by (i) directly transferring fertilized eggs obtained from adults acclimated to sea water at a salinity of 30‰ to cultures containing seawater at salinities of 30, 27.5, 25, 22.5, 20, 17.5, 15, 12.5, and 10‰ at 10 °C; and (ii) acclimation of adult sea urchins to the salinity–temperature conditions described above for 2, 3, and 4 weeks prior to spawning. Subsequent development occurred under these acclimation conditions. Development rates and percent survival of larvae prior to metamorphosis varied directly with salinity. Survival of S. pallidus plutei to metamorphosis decreased at salinities below 30‰. Strongylocentrotus droebachiensis plutei survived to metamorphosis at 20‰ and above. Lactic acid concentrations in the coelomic cavity fluid of adult S. droebachiensis and S. pallidus acclimated to low salinity were significantly higher than initial controls at 30‰. Cell volumes of fertilized eggs of both species exhibited osmotic swelling when exposed to lowered salinity. LC50 values (‰), development rates, and percent survival to metamorphosis indicate that acclimation of adult urchins to lower salinity prior to spawning and fertilization does not enhance development or survival of embryos of these two species exposed to low salinity. Furthermore, our results show that S. pallidus larvae are stenohaline when compared with larvae of other echinoderm species.

Responses and acclimation to salinity in the adults of some balanomorph barnacles

1970 ◽  
Vol 256 (810) ◽  
pp. 377-400 ◽  
Keyword(s):  
Blood Concentration ◽  
Sea Water ◽  
Freezing Point ◽  
Mantle Cavity ◽  
Salinity Acclimation ◽  
Low Salinity ◽  
Tissue Resistance ◽  
Wide Range ◽  
External Salinity ◽  
Balanus Balanoides

The responses of a number of barnacles to a wide range of salinity have been studied by observation of the activity and measurement of the depression of freezing point of the blood. In active barnacles of the species Elminius modestus, Balanus balanoides, B. crenatus, B. improvisus, B. hameri, B. balanus and Chthamalus stellatus the blood concentration conforms with changes in the external salinity. The concentration of the blood tends to remain slightly hyperosmotic to the fluid in the mantle cavity, and to the medium. With sudden changes of external salinity the blood concentration conforms within a few hours if cirral activity is maintained. When placed in such low salinities that activity is inhibited, E. modestus, B. balanoides, B. crenatus, B. improvisus, B. balanus and C. stellatus close the opercular valves with the result that the blood and mantle cavity fluid are maintained for some time at a level initially considerably hyperosmotic to the medium, but the blood is still only slightly hyperosmotic to the fluid remaining in the mantle cavity. There is no permanent control, and in time the blood concentration approximates to the external level. E. modestus, B. balanoides and B. improvisus from low salinity estuarine habitats, and B. crenatus after gradual reduction of salinity in the laboratory over a matter of days, exhibit tolerance to lower salinities than do specimens of the same species obtained from, or acclimated to normal salinities. Salinity acclimation is typical of osmoconformers lacking specific organs for effective regulation. It is concluded that the barnacles here tested are osmoconformers, able to adjust to small changes of environmental salinity by tissue acclimation, but evading too severe salinity changes by withdrawing into the protection of the shell. The deep sea B. hameri , however, does not close up when immersed in dilute sea water, and appears to be relatively stenohaline with limited ability to acclimate to low salinity. The intertidal E. modestus and B. balanoides , and the low-tidal to sublittoral B. crenatus , are tolerant, after experimental or natural acclimation, of salinities down to 14 to 17 ‰. The estuarine B. improvisus can, with gradual acclimation, be induced to be active in a salinity of about 2 ‰ . This species is remarkably tolerant of dilution of the blood, and its distribution into regions of low salinity is evidently due to a wide tissue resistance and not to any ability to regulate.

Evidence for Association of Vibrio Echinoideorum with Tissue Necrosis on Body Shell of the Green Sea Urchin Strongylocentrotus Droebachiensis

2021 ◽  
Author(s):  
Jonathan Hira ◽  
Klara Stensvåg
Keyword(s):  
Sea Urchin ◽  
Virulence Genes ◽  
Vibrio Vulnificus ◽  
Sea Urchins ◽  
Opportunistic Pathogen ◽  
Significant Degree ◽  
Strongylocentrotus Droebachiensis ◽  
Host Immune System ◽  
Progressive Development ◽  
Green Sea Urchin

Abstract “Sea urchin lesion syndrome” is known as sea urchins disease with the progressive development of necrotic epidermal tissue and loss of external organs, including appendages on the outer body surface. Recently, a novel strain, Vibrio echinoideorum has been isolated from the lesions of green sea urchin (Strongylocentrotus droebachiensis), an economically important mariculture species in Norway. V. echinoideorum has not been reported elsewhere in association of with green sea urchin lesion syndrome. Therefore, in this study, an immersion based bacterial challenge experiment was performed to expose sea urchins (wounded and non-wounded) to V. echinoideorum, thereby mimicking a nearly natural host-pathogen interaction under controlled conditions. This infection experiment demonstrated that only the injured sea urchins developed the lesion to a significant degree when exposed to V. echinoideorum. Pure cultures of the employed bacterial strain was recovered from the infected animals and its identity was confirmed by the MALDI-TOF MS spectra profiling. Additionally, the hemolytic phenotype of V. echinoideorum substantiated its virulence potential towards the host, and this was also supported by the cytolytic effect on red spherule cells of sea urchins. Furthermore, the genome sequence of V. echinoideorum was assumed to encode potential virulence genes and were subjected for in silico comparison with the established virulence factors of Vibrio vulnificus and Vibrio tasmaniensis. This comparative virulence profile provided novel insights about virulence genes and their putative functions related to chemotaxis, adherence, invasion, evasion of the host immune system, and damage of host tissue and cells. Thus, it supports the pathogenicity of V. echinoideorum. In conclusion, the interaction of V. echinoideorum with injured sea urchins appears to be essential for the development of lesion syndrome and therefore, revealing its potentiality as an opportunistic pathogen.

Effect of temperature on somatic growth and survivorship of early post-settled green sea urchins, Strongylocentrotus droebachiensis (Müller)

2005 ◽  
Vol 36 (6) ◽  
pp. 600-609 ◽  
Author(s):  
Christopher M Pearce ◽  
Sean W Williams ◽  
Fu Yuan ◽  
John D Castell ◽  
Shawn M C Robinson
Keyword(s):  
Sea Urchins ◽  
Somatic Growth ◽  
Strongylocentrotus Droebachiensis ◽  
Effect Of Temperature

The opening response of mussels (Mytilus edulis) exposed to rising sea-water concentrations

1981 ◽  
Vol 61 (3) ◽  
pp. 667-678 ◽  
Author(s):  
John Davenport
Keyword(s):  
Mytilus Edulis ◽  
Sea Water ◽  
External Medium ◽  
Mantle Cavity ◽  
Low Salinity ◽  
Medium Exchange ◽  
Mantle Edge

When exposed to water of low salinity specimens of Mytilus edulis L. keep their shell valves tightly closed; they do not gape periodically to test the external medium. Exchange of salts and water between the mantle cavity and the environment is thus minimized. Rising salinities are registered by diffusion of salts to the tentaculate portion of the inhalent siphon and not to any other portion of the mantle edge or to any more deeply located structures.

Geographic and environmental factors affecting the distribution of kelp beds and barren grounds and changes in biota associated with kelp reduction at sites along the Norwegian coast

1997 ◽  
Vol 54 (12) ◽  
pp. 2872-2887 ◽  
Author(s):  
Knut Sivertsen
Keyword(s):  
Environmental Factors ◽  
Sea Urchins ◽  
Strongylocentrotus Droebachiensis ◽  
The Arctic ◽  
Laminaria Hyperborea ◽  
Factors Affecting ◽  
Kelp Beds ◽  
The Mean ◽  
Transition Areas ◽  
Barren Grounds

Sites at 244 locations along the west and north Norwegian coasts were investigated to evaluate whether kelp (Laminaria hyperborea) beds had been overgrazed by the sea urchins Strongylocentrotus droebachiensis and Echinus esculentus in the years 1981-1992. Barren ground communities were found in sheltered and moderately wave-exposed areas mainly in the inner and middle archipelago from Nordmøre (63°N) northwards. Densities of large-sized (adult and intermediate) L. hyperborea were 20.7 individuals ·m-2 in kelp beds and 9.7 individuals ·m-2 in transition areas. Juvenile Laminaria spp. were present at densities of 23.9 individuals ·m-2 in kelp beds, 3.6 individuals ·m-2 in transition areas, 0.0 individuals ·m-2 in barren grounds, and 59.1 individuals ·m-2 in kelp-harvested locations. Both the densities and the mean size of S. droebachiensis in barren grounds decreased northwards. The mean densities were 52.2 and 26.1 individuals ·m-2 for the areas south and north of the Arctic Circle, respectively. Multivariate analysis (CANOCO) showed that seven ``environmental'' factors (i.e., kelp depth gradient, distance (latitude), time of sampling, nematode infection in S. droebachiensis, wave exposure, coastal gradient, and substratum) contributed significantly to variability in the distribution of kelp beds and barren grounds. Species in hard-bottom communities in shallow waters could be divided into three distinct BIOTA.

ACID-BASE REGULATION, BRANCHIAL TRANSFERS AND RENAL OUTPUT IN A MARINE TELEOST FISH (THE LONG-HORNED SCULPIN MYOXOCEPHALUS OCTODECIMSPINOSUS) DURING EXPOSURE TO LOW SALINITIES

1994 ◽  
Vol 193 (1) ◽  
pp. 79-95 ◽  
Author(s):  
J Claiborne ◽  
J Walton ◽  
D Compton-Mccullough
Keyword(s):  
Teleost Fish ◽  
Sea Water ◽  
Carbon Dioxide Concentration ◽  
Marine Teleost ◽  
Total Acid ◽  
Low Salinity ◽  
External Salinity ◽  
First Time ◽  
Marine Teleost Fish

A number of studies have implied a linkage between acid­base and ion exchanges in both freshwater and seawater fish, although little is known about the branchial and renal acid­base transfers involved as the animals move between different salinities. To investigate the role of these transfers in a marine teleost fish as it is exposed to a dilute environment, we measured plasma acid­base values and net movements from fish to water of NH4+, HCO3- and H+ in long-horned sculpin (Myoxocephalus octodecimspinosus) placed in 100 %, 20 %, 8 % or 4 % sea water for 24­48 h. Renal excretion of H+ was also monitored in fish exposed to 4 % sea water. Sculpin proved to be somewhat euryhaline for they were able to maintain plasma ion and acid­base transfers in hypo-osmotic (20 %) sea water, but could not tolerate greater dilutions for more than several days. Plasma pH and carbon dioxide concentration (CCO2) increased in the 20 % and 8 % dilution groups, with CCO2 nearly doubling (control, 4.56 mmol l-1; 8 % group, 8.56 mmol l-1) as a result of a combined increase in the partial pressure of plasma CO2 (PCO2) and [HCO3-]. During a 44­46 h exposure, HCO3- transfers increased progressively in the most dilute water, with animals in the 8 % and 4 % groups exhibiting a net H+ loss that was smaller than that of seawater fish (control, 5.1 mmol kg-1; 8 %, 0.9 mmol kg-1; 4 %, -2.9 mmol kg-1). Animals exposed to 4 % sea water for 24 h and then returned to normal sea water had a variable plasma pH, an elevated CCO2 and a net efflux of H+ that effectively stopped (control, 0.10 mmol kg-1 h-1; 4 %, 0.02 mmol kg-1 h-1; seawater recovery, 0.20 mmol kg-1 h-1) during the low-salinity period. Renal acid excretion remained relatively constant throughout the experiment but only made up a significant portion (approximately 40 %) of the total acid transfers during the 4 % dilution period (control rate approximately 3 µmol kg-1 h-1: 3 % of branchial rate). We postulate that the increase in plasma CCO2 during exposure to low salinity may be due to mobilization of base from the intracellular bone compartment. The decrease in external salinity could induce base loss by alteration of gill ion exchanges (Na+/H+, Cl-/HCO3-) and/or changes in branchial HCO3- permeability. For the first time, we have shown that the effects of a dilute environment on acid­base transfers may be an important limitation to the survival of a euryhaline species in brackish or fresh water.

The Effect of Salinity Changes on the Water Content and Respiration of Marine Invertebrates

1931 ◽  
Vol 8 (3) ◽  
pp. 211-227
Author(s):  
L. C. BEADLE
Keyword(s):  
Respiratory Rate ◽  
Marine Invertebrates ◽  
Sea Water ◽  
Oxygen Intake ◽  
Anaerobic Conditions ◽  
Marine Animals ◽  
Surrounding Water ◽  
Low Salinity ◽  
Initial Difference ◽  
Good Support

1. Schlieper's theory of the function of increased oxygen intake by "homoiosmotic" marine invertebrates in dilute sea water in maintaining their body fluids hypertonic to the surrounding water is discussed, and objections are brought forward to the methods used in the experiments on which his conclusions were based. 2. By periodic weighings, and measurements of respiratory rate (under narcotic) by Barcroft manometers, it was found that the weight of N. diversicolor, on transference to water of low salinity, at first increases and then falls, and that the respiratory rate is at first increased and later tends to decrease. 3. With N. cultrifera the weight increases to a higher value and does not sub sequently fall, and the respiratory rate is also increased but to a lesser extent than with N. diversicolor. 4. These differences in the amount of increase in respiratory rate are more marked in water containing only 16.6 per cent, sea water than in water containing 25 per cent, sea water. 5. N. diversicolor maintains its activity while N. cultifera becomes practically inert in dilute water. The latter does not actually die in 25 per cent, sea water after 100 hours, but dies in 16.6 per cent, sea water after about 50 hours. 6. Exposure to M/1000 KCN or to anaerobic conditions in dilute water tends to break down the mechanism by which the free osmotic inflow of water in N. diversicolor is prevented, and the weight curves under these conditions approach the N. cultrifera form. 7. The respiratory rate of G. ulvae increases progressively with dilution of the sea water, and is roughly proportional to the initial difference of osmotic pressure inside and outside the animal. 8. The swelling of Gunda in dilute water is due to swelling of the gut cells, which become much vacuolated. The other tissues appear unaltered. 9. M/1000 KCN or anaerobic conditions cause a greater amount of swelling in Gunda in a given salinity than normally occurs. 10. These experiments seem to give reasonably good support to Schlieper's hypothesis. 11. The mechanism responsible for this "osmotic resistance" in N. diversicolor must be of a somewhat different nature from that in G. ulvae. 12. A rigid distinction between "homoiosmotic" and "poikilosmotic" marine animals cannot be supported.

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