Fast pressure pulses and communication between fish

1991 ◽  
Vol 71 (1) ◽  
pp. 83-106 ◽  
Author(s):  
J. A. B. Gray ◽  
E. J. Denton
Keyword(s):  
Sea Water ◽  
Opposite Polarity ◽  
Clupea Harengus ◽  
Free Swimming ◽  
Pressure Fields ◽  
Pressure Pulses ◽  
Merlangius Merlangus ◽  
Electrical Stimuli ◽  
Two Sides ◽  
Fast Pulse

Experiments on herring (Clupea harengus L.), sprat (Sprattus sprattus (L.)) and whiting (Merlangius merlangus (L.)) showed that when these fish make rapid swimming movements, such movements are preceded by fast pressure pulses in the surrounding sea water. Thefirst (a) phases of these pulses had durations of from 1–5 to 3–5 ms. The pulses could be excited in free-swimming fish by both visual and auditory stimuli and the latencies to the latter ranged from 5 to 8–5 ms. Identical pulses could be elicited by giving electrical stimuli to anaesthetized fish; these pulses had latencies from 34 to 7 ms.The pressure fields around the fish were measured on suspended anaesthetized fish stimulated electrically. At any instant the fields of the fast pulses produced by whiting had the same polarity at all positions round the fish and pressure decayed inversely with the 1–5 powerof distance. The a phase of the fast pulse was usually a decompression.The fields around a stimulated herring were different. The pressures on both sides oppositethe centre of the fish were of one polarity while those around the head and the tail were of the opposite polarity, the pattern of pressure being symmetrical about the long axis of the fish.In our experiments the a phase opposite the centre of the fish was always a compression. The amplitudes of these pulses declined with distance by the power of 2–5. In all species in our experiments the fast pulses were followed by slower pulses associated with swimming movements; these slower pulses had opposite polarities at corresponding points on the two sides of the fish.

The Effects of External Salinity on the Drinking Rates of the Larvae of Herring, Plaice and Cod

1988 ◽  
Vol 138 (1) ◽  
pp. 1-15 ◽  
Author(s):  
P. TYTLER ◽  
J. H. BLAXTER
Keyword(s):  
Time Course ◽  
Gadus Morhua ◽  
Sea Water ◽  
Fluorescein Isothiocyanate ◽  
Yolk Sac ◽  
Clupea Harengus ◽  
Larval Stages ◽  
First Feeding ◽  
Fluorescein Isothiocyanate Dextran ◽  
External Salinity

Drinking responses to salinity change in the larvae of herring (Clupea harengus L.), plaice (Pleuronectes platessa L.) and cod (Gadus morhua L.) were measured from the time course of uptake of dextran labelled with tritium, following immersion in solutions of 32‰ and 16‰ sea water. The yolk sac and first feeding larval stages of all three species drink in both salinities. Furthermore, post-yolk sac stages appear to adjust their drinking rates to compensate for different salinities in a manner similar to that of the adults. Drinking rates in 32‰ sea water are approximately double those in 16‰. Mass-related drinking rates of larvae are higher than those in adults, but the differences do not match the differences in surface area to mass ratios, suggesting that larval skin is less permeable to water than is adult gill epithelium. Water absorption is indicated by the evidence of concentration of dextran in the gut. The estimates of drinking rates from tritiated dextran uptake are supported by epifluorescence microscopical measurements of the uptake of fluorescein isothiocyanate dextran.

Influence of environmental conditions, population density, and prey type on the lipid content in Baltic herring (Clupea harengus membras) from the northern Baltic Sea

2019 ◽  
Vol 76 (4) ◽  
pp. 576-585 ◽  
Author(s):  
Marjut Rajasilta ◽  
Jari Hänninen ◽  
Lea Laaksonen ◽  
Päivi Laine ◽  
Jukka-Pekka Suomela ◽  
...  
Keyword(s):  
Climate Change ◽  
Baltic Sea ◽  
Lipid Content ◽  
Sea Water ◽  
Energy Content ◽  
Global Climate ◽  
Clupea Harengus ◽  
Composition Analysis ◽  
Baltic Herring ◽  
The Baltic

Global climate change can affect the energy content of fish by altering their lipid physiology and consumption. We investigated the effects of different environmental stressors on the lipid content of the Baltic herring (Clupea harengus membras) from spawning ground samples that were collected annually in the northern Baltic Sea. During 1987–2014, the average lipid content of herring muscle decreased from 5%–6% (wet mass) to 1.5% (wet mass). Generalized linear mixed models indicated that sea water salinity and the size of the herring stock explained best the declining trend of lipid content. We estimated that the amount of the lipid storage incorporated in the spawning stock decreased by approximately 45% during the study, with respective energy content decreases. Fatty acid composition analysis revealed that herring lipids contained a high proportion of EPA (eicosapentaenoic acid; 20:5n-3) and DHA (docosahexaenoic acid; 22:6n-3), which likely originated from its main summertime prey, Limnocalanus macrurus. The results illustrate various climate change-induced processes leading to changes in the lipid content of the Baltic herring and, consequently, to changes in the energy flows of the northern Baltic ecosystem.

On The Fine Structure of Lateral-Line Canal Organs of the Herring (Clupea Harengus)

1985 ◽  
Vol 65 (3) ◽  
pp. 751-758 ◽  
Author(s):  
J. Mørup Jørgensen
Keyword(s):  
Lateral Line ◽  
Moving Objects ◽  
Sea Water ◽  
Clupea Harengus ◽  
Lateral Line System ◽  
Pressure Waves ◽  
Canal System ◽  
Line System ◽  
Lateral Line Canal ◽  
Lower Vertebrates

The lateral-line system of water-living lower vertebrates is provided with mechanoreceptors enabling the animals to detect water displacements, either caused by moving objects such as prey, predators or neighbours in a school or by deformations of pressure waves from the swimming animal caused by other objects. Cyclostomes, some fish and water–living amphibians have their lateral-line organs situated superficially in the epidermis as free neuromasts, while most fish besides these neuromasts possess a canal system in the dermis. Ordinarily the lateral line canal system consists of a few canals on the sides of the head and a trunk canal. In herring, however, the canal system is confined to the head and opercule. It forms a very richly branched system with numerous pores which connect the canal fluid with the surrounding sea water.

Physical Properties and Hydrostatic Function of the Swimbladder of Herring (Clupea harengus L.)

1962 ◽  
Vol 19 (4) ◽  
pp. 635-656 ◽  
Author(s):  
Vivien M. Brawn
Keyword(s):  
Surface Pressure ◽  
Sea Water ◽  
Gas Production ◽  
Clupea Harengus ◽  
Gas Release ◽  
Pressure Reduction ◽  
Neutral Buoyancy ◽  
Reduced Pressure ◽  
Pressure Decrease ◽  
Mean Pressure

Living herring at the depth of adjustment had a mean sinking factor of 1003, density of 1.026 g/ml, relative sensitivity of 0.8 and percentage swimbladder volume of 4.2. Neutral buoyancy was attained at a mean pressure reduction of 5.5% from the adjusted pressure. Swimbladder gas was under an average excess pressure of 1 cm Hg. Gas was released through the posterior swimbladder duct during pressure reduction in 105 out of 109 herring observed. Gas release occurred at a mean pressure decrease of 6% in rapidly swimming herring, at 32% in moderately swimming fish and brought the herring to within 19% of perfect adjustment to a new reduced pressure within half an hour. Herring could compensate for their increased buoyancy during pressure decrease until this was reduced by gas release. Decompression at rates up to 123 cm Hg/sec was not fatal after 16 hours at the greater pressure. No recovery of buoyancy after gas loss occurred in herring held 24 hours in running sea water even if fine air bubbles were present. Recovery occurred if these fish had access to the surface. Gas production by bacterial activity as a means of restoring buoyancy was not established. Herring responded to rapid pressure increases by swimming upwards. They could compensate for their increased density following pressure increase of 300% and survive increases of 430%. Herring from 10 to 25 feet depth at sea were positively buoyant at surface pressure when anaesthetized. Thus in nature herring are adjusted to pressures greater than surface pressure. It is suggested that they take in air when feeding at the surface at night and slowly pass this to the swimbladder on returning to greater depths by day.

The Sensitivity of Barnacles and Their Larvae to Copper and Mercury

1948 ◽  
Vol 25 (3) ◽  
pp. 276-298
Author(s):  
K. A. PYEFINCH ◽  
JOAN C. MOTT
Keyword(s):  
Life History ◽  
Toxic Effect ◽  
Sea Water ◽  
Short Interval ◽  
Sharp Decrease ◽  
Short Exposure ◽  
Sharp Change ◽  
Older Individuals ◽  
Free Swimming ◽  
Wide Range

1. Experiments on the toxic effects of copper and of mercury on various stages in the life history, nauplii, cyprids, metamorphosing cyprids and adults of acorn barnacles are described. Most of the work has been carried out on the appropriate stages of Balanus balanoides, but it has been supplemented, wherever possible, by parallel experiments using B. crenatus. 2. Cupric sulphate and mercuric chloride solutions were used as sources of the poisons, and the actual concentration of poison present was determined at the end of each experiment. The period of exposure to the poison was usually 6 hr. 3. A sharp decrease in sensitivity occurs, both in B. balanoides and B. crenatus, between the last naupliar stage and the cyprid. The relative sensitivity of the cyprid of B. balanoides to copper and to mercury is similar to that of the sixth stage nauplius, but the cyprid of B. crenatus is particularly insensitive to copper, but is more sensitive to mercury than that of B. balanoides. 4. Cyprids of B. balanoides only settle in the laboratory some 4 or 5 days after being taken in the plankton and during this period the sensitivity to copper and mercury increases. Settlement can be prevented by very low concentrations of copper and mercury, even though there are no obvious lethal effects. The cyprid of B. crenatus settles more readily in the laboratory, and little change in sensitivity seems to occur during the short interval between catching and settlement. 5. Metamorphosis of the cyprid of either B. balanoides or B. crenatus cannot be prevented by the concentrations of copper (up to 7 mg./l.) possible in sea water. This means that another sharp change in sensitivity occurs after the cyprid of the former species has settled but, because of the low sensitivity of the free-swimming cyprid of B. crenatus, such a change has not been detected for this species. 6. The young barnacle of both species immediately after metamorphosis is much more sensitive to copper than the metamorphosing cyprid. For B. balanoides the sensitivity, both to this poison and to mercury does not change significantly as the barnacle grows, but a small specimen of B. crenatus (less than one month old) is appreciably less sensitive, both to copper and to mercury, than slightly older individuals. 7. Copper and mercury appear to be roughly equi-toxic to the adult of B. balanoides; the adult B. crenatus is slightly more sensitive to copper and distinctly less sensitive to mercury than that of B. balanoides. 8. In view of these differences in sensitivity of the various stages in the life history of two closely related species, the results obtained with one species should not be held to apply to other species of barnacles. 9. A number of other experiments were carried out using the free-swimming cyprids of B. balanoides. Diluted sea water, though it has no toxic effect in itself over short exposure periods, markedly reduces the toxicity of both copper and mercury. Hypertonic sea water also reduces the toxicity of copper. The sensitivity of these larvae to either copper or mercury is not affected by the presence of sodium oleate. Exposure of these larvae to a wide range of copper concentrations in artificial sea water reveals certain anomalies which may be important in explaining the results obtained when they are exposed to mixtures of copper and mercury in natural sea water. The toxic effect of mercury seems to be similar in either natural or artificial sea water.

Osmotic regulation in the embryo of the herring (Clupea harengus)

1965 ◽  
Vol 45 (2) ◽  
pp. 305-311 ◽  
Author(s):  
F. G. T. Holliday ◽  
M. Pattie Jones
Keyword(s):  
Sea Water ◽  
Freezing Point ◽  
Body Fluids ◽  
Clupea Harengus ◽  
Osmotic Regulation ◽  
Osmotic Concentration ◽  
Significant Change

Just before spawning the semen of the herring is isosmotic with the parent blood, the eggs are hyposmotic. Immediately the eggs are placed in sea water of salinities 5, 17·5, 35 and 50 %0 there is a change in the freezing-point of the yolk indicating that it has approached close to being isosmotic with the water. Changes in the freezing-point of the yolk during development indicate that the overgrowing embryo gradually regulates the osmotic concentration of the yolk, although full regulation is not achieved until after the closing of the blastopore. After this point there is no significant change in the freezing-point of the yolk or body fluids. Regulation is most probably brought about by the activity of the cells of the ectoderm.

scholarly journals Vertical distribution and feeding patterns in fish foraging on the krill Meganyctiphanes norvegica

2004 ◽  
Vol 61 (8) ◽  
pp. 1278-1290 ◽  
Author(s):  
M.S.R. Onsrud ◽  
S. Kaartvedt ◽  
A. Røstad ◽  
T.A. Klevjer
Keyword(s):  
Middle Part ◽  
Clupea Harengus ◽  
Antipredator Behaviour ◽  
Fish Schools ◽  
Fish Predators ◽  
Meganyctiphanes Norvegica ◽  
Merlangius Merlangus ◽  
Deep Site ◽  
Fish Abundances ◽  
High Fish

Abstract Fish and krill were studied at a 120 m deep site in the Oslofjord, Norway. Herring (Clupea harengus), whiting (Merlangius merlangus), and Norway pout (Trisopterus esmarkii) were foraging on krill (Euphausiacea, Meganyctiphanes norvegica) during both day and night. During daytime, herring and whiting were foraging in the upper and middle part of the krill assemblage, while the deep-living, and often benthopelagic Norway pout was approaching the krill from below. Krill and fish ascended and fish schools dispersed at dusk. At night, herring and whiting were feeding near the surface, with the shallowest distribution suggested for herring. Norway pout foraged in midwater. Krill antipredator behaviour comprised diel vertical migration and instantaneous escape reactions, and the krill also appeared to actively seek out strata with low acoustic recordings of fish. Fish accumulated beneath the research vessel when the ship was anchored at a fixed location during acoustic studies, apparently resulting in artificially high local fish abundances. Since we suggest that krill respond to the presence of fish, such high fish abundance may bias studies of interactions between the fish predators and their krill prey.

Oxygen and the developing eggs and larvae of the lumpfish, Cyclopterus lumpus

1983 ◽  
Vol 63 (3) ◽  
pp. 633-640 ◽  
Author(s):  
John Davenport
Keyword(s):  
Oxygen Uptake ◽  
Sea Water ◽  
Early Stage ◽  
Clupea Harengus ◽  
Low Oxygen ◽  
Egg Masses ◽  
Cyclopterus Lumpus ◽  
Hypoxic Conditions ◽  
Slow Development ◽  
Eggs And Larvae

Unfertilized eggs in the oviducts of female lumpsuckers are exposed to low oxygen tension (ca. 40% air saturation). After spawning and fertilization water agitation aids percolation of water through Cyclopterus egg masses, but early in development oxygen tensions within non-ventilated egg masses fall slowly because of the eggs’ low metabolic rate (consistent with their slow development – 40 days to hatching at 5 °C). There is a considerable increase in oxygen uptake at hatching; in this respect the lumpsucker resembles the herring, Clupea harengus.Early stage eggs are tolerant of hypoxic conditions and can even survive brief exposure to anoxic sea water. Later eggs and larvae are much more susceptible to oxygen lack. However, fanning behaviour by the brooding male parent (usually assumed to be designed to promote oxygen uptake by egg masses) is almost continuous at the beginning of development but becomes less frequent later. It is suggested that the initial intensive fanning helps to drive off ammonia which is released as the eggs stick together.

Catch Handling and the Possible Migration of Anisakis Larvae in Herring, Clupea harengus

1993 ◽  
Vol 56 (9) ◽  
pp. 783-787 ◽  
Author(s):  
ALLAN ROEPSTORFF ◽  
HORST KARL ◽  
BOUKE BLOEMSMA ◽  
HANS H. HUSS
Keyword(s):  
North Sea ◽  
Quantitative Method ◽  
Sea Water ◽  
Clupea Harengus ◽  
The Mean

The behavior of larvae of Anisakis sp. in North Sea herring (Clupea harengus) after capture was examined by a sensitive quantitative method (digestion). In one winter and one summer experiment, the mean numbers of worms in freshly caught herring were 0.06 and 0.09 (in double fillets), 0.19 and 0.24 (in double belly flaps), and 10.4 and 7.8 larvae (in viscera), respectively. In each experiment herrings were stored ungutted for up to 5 1/2 d on ice (0°C), in refrigerated/chilled sea water (−10°C), or in warm sea water (10°C), but no changes in the numbers of Anisakis larvae in the belly flaps and the fillets could be demonstrated. The present results show that Anisakis larvae are present in the flesh of herring already at capture, but no significant postmortem migration into the flesh could be demonstrated during storage. Thus, immediately gutting on board cannot eliminate or even reduce the risk from eating raw or inadequately processed herring.

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