A Note on the Development of Eggs and Larvae of the Bogue, Boops Boops

1984 ◽  
Vol 64 (3) ◽  
pp. 729-731
Author(s):  
S. H. Coombs ◽  
C. E. Mitchell
Keyword(s):  
Sea Water ◽  
Adult Fish ◽  
Bottom Temperature ◽  
Bottom Trawling ◽  
Different Temperatures ◽  
Artificial Fertilization ◽  
Males And Females ◽  
Incubation Temperatures ◽  
Boops Boops ◽  
Eggs And Larvae

An opportunity was taken to carry out the artificial fertilization and incubation at different temperatures of eggs of the bogue, Boops boops (Linnaeus, 1758) during a cruise on R.V. 'Cirolana' organized by the Fisheries Laboratory, Lowestoft. Adult fish for use in the experiment were obtained by bottom trawling in 165 m depth of water at 43° 44' N02° 44' W on 10 May 1980 between 0449 and 0549 h GMT. The bottom temperature at the trawling position was estimated to be ~ 11 · 8 °C, based on measurements made at nearby stations. Eggs and milt from several males and females were added to a container of sea waterheld at approximately 11 °C; after 1 h the fertilized eggs were transferred as four separate subsamples each of approximately too eggs to clean sea water in the incubation beakers. Thesebeakers were then gradually acclimatized over a period of 2 h to the incubation temperatures of80, 131, 182 and 22·8°C.At all temperatures mortality was high during early embryonic development. At 228 °C all eggs were dead after 9J h of incubation at which time some of these specimens had formed a blastoderm cap, but with no sign of overgrowth of the yolk. In a few of the eggs held at 80 °C development proceeded normally until immediately before closure of the blastopore (~ 106 h after ferilization) when irregular vacuoles were seen in the area around the blastopore and development was disrupted; after 112 h of incubation all eggs held at 80 °C were dead.

scholarly journals Фенотипическая пластичность в соотношении полов у Idotea baltica basteri (Crustacea, Isopoda) в Одесском заливе Черного моря

2014 ◽  
Vol 5 (1) ◽  
pp. 49-53 ◽  
Author(s):  
A. Y. Varigin
Keyword(s):  
Water Exchange ◽  
Sea Water ◽  
The Black Sea ◽  
Fouling Community ◽  
Gradual Decline ◽  
Idotea Baltica ◽  
Open Sea ◽  
Males And Females ◽  
Exchange Intensity ◽  
Number Of Males

The degree of phenotypic plasticity in the Idotea baltica basteri Audouin, 1827 (Crustacea, Isopoda) sex ratio of the fouling community in the Odessa bay of the Black Sea was determined. The ratio of males and females in three main phenotypes of I. baltica basteri, namely: uniformis, albafusca and lineata was found. Crustaceans were collected on the underwater surface of traverses, located in three sea districts with the different degrees of water exchange intensity with the open sea. Water depth at the wall of traverses ranged from 1 to2,5 m. In the first most opened district among the individuals of uniformis phenotype the ratio of males and females was equal to 1:4, that for albafusca – 1:1,3 and lineata – 1:1. In the second area with the release of drainage waters among the individuals of uniformis phenotype this ratio was equal to 1:4,5, while the albafusca and lineata figures were 1:1,5 and 1:1, accordingly. In the third region, with the most difficult water exchange, among the individuals of phenotypes the ratios of males and females were as follows: uniformis – 1:8, albafusca – 1:2, and lineata – 1:1. When moving from the opened to semi-enclosed area among the individuals of all phenotypes there was a gradual decline in the proportion of males and accordingly, increases of the proportion of females. The greatest number of males in all areas under study is observed among the individuals of lineata phenotype, and that of females – among the individuals of uniformis phenotype. It is found that monochromatic colored females prefer to stay in the shaded places among the seagrass beds and brightly colored males usually move actively along the outside of the substrata. 

scholarly journals THE TIME CURVE OF FACET DETERMINATION IN AN ULTRABAR STOCK OF DROSOPHILA MELANOGASTER

1934 ◽  
Vol 17 (4) ◽  
pp. 487-498 ◽  
Author(s):  
A. H. Hersh
Keyword(s):  
Drosophila Melanogaster ◽  
Time Course ◽  
Arrhenius Equation ◽  
Temperature Relation ◽  
Time Curve ◽  
Velocity Constant ◽  
Effective Period ◽  
Different Temperatures ◽  
Sigmoid Curve ◽  
Males And Females

By a dissection of the data obtained by Driver on the effective periods at different temperatures in males and females of an ultrabar stock of Drosophila melanogaster it has been found that a symmetrical sigmoid curve satisfactorily describes the time course of the facet-determining reaction. Consequently the differences between members of the bar series in regard to this reaction do not represent merely developmental arrests of the process at some greater or lesser distance from a common upper asymptote, but the termination of the process is approached asymptotically. The velocity constant/temperature relation shows a discontinuity in the neighborhood of 21° which may be causally related to the change in the position of the effective period from the second to the third instar. The velocity constant apparently does not conform to the well known Arrhenius equation in its relation to temperature.

scholarly journals The Melting of Free-Drifting Icebergs

1980 ◽  
Vol 1 ◽  
pp. 119-122 ◽  
Author(s):  
D. S. Russell-Head
Keyword(s):  
Low Temperature ◽  
Water Temperature ◽  
Population Studies ◽  
Sea Water ◽  
Surface Shape ◽  
Different Temperatures

Blocks of ice with the proportions of tabular icebergs have been observed melting in water of different temperatures and salinities. The sub-surface shape adopted by the blocks melting in water of the same salinity as sea-water was typically a ‘bath-tub’ one. The basal and mean-side melt rates were of a similar value. The melt rates obtained in the laboratory for icebergs in water of a low temperature match those inferred from population studies of Antarctic icebergs. The melt rate is proportional to the water temperature above the onset of freezing raised to the power 1.5 and melt rates at 18°C are likely to be greater than one metre per day.

TEMPERATURE-DEPENDENT DEVELOPMENT OF EGGS AND LARVAE OF WINTHEMIA FUMIFERANAE TOTH. (DIPTERA: TACHINIDAE), A LARVAL–PUPAL PARASITOID OF THE SPRUCE BUDWORM (LEPIDOPTERA: TORTRICIDAE)

1990 ◽  
Vol 122 (2) ◽  
pp. 329-341 ◽  
Author(s):  
Christian Hébert ◽  
Conrad Cloutier
Keyword(s):  
Spruce Budworm ◽  
Development Rate ◽  
Temperature Dependent ◽  
Egg Development ◽  
Egg Hatching ◽  
Egg Deposition ◽  
Different Temperatures ◽  
Time Required ◽  
The Relationship ◽  
Eggs And Larvae

AbstractRelationships between temperature and development rates of eggs and larvae of Winthemia fumiferanae Toth. were experimentally determined, using the spruce budworm as host. Hatching of parasitoid eggs was triggered by host pupation. The median time required to complete egg development at different temperatures was estimated from distributions of percentage development success of the parasitoid over time between egg deposition and host pupation. For parasitoid eggs that had sufficient time to hatch, detachment from the host before pupation was the most important cause of mortality at 15 °C or higher, but was negligible below this temperature. A curvilinear model describing egg development rate as a function of temperature was used to simulate the development of W. fumiferanae eggs in the field. The relationship between larval development rate and temperature also was modelled, and the variability described. Simulations initiated by host pupation-driven egg hatching, and terminated with prepupal drop to the ground, are presented and discussed with respect to the appropriateness of using host pupation as an indicator of parasitoid egg hatching in the field.

Observations on the free-living stages of strongylid nematodes of the horse

Parasitology ◽  
1972 ◽  
Vol 64 (3) ◽  
pp. 461-477 ◽  
Author(s):  
C. P. Ogbourne
Keyword(s):  
Laboratory Experiments ◽  
Field Observations ◽  
Infective Stage ◽  
Free Living ◽  
Rate Of Development ◽  
Infective Larvae ◽  
Strongylus Vulgaris ◽  
Different Temperatures ◽  
Eggs And Larvae

Observations have been made on the development and survival of the free-living stages in faeces deposited out of doors at different times of year, and on the migration of infective larvae to the surrounding herbage. Laboratory experiments were performed to assist in the interpretation of the field observations. Studies were made on the rate of development to the infective stage in faeces kept at different temperatures. The rates at which eggs and larvae of Strongylus vulgaris, S edentatus, S. equinus and Trichonema nassatum developed on faecal-agar cultures at different temperatures were compared. Studies were also made on the effect of desiccation of faeces on the development and survival of the free-living stages. The results of these observations are discussed in relation to the development of herbage infestations on British pastures.

Ammonia output by eggs and larvae of the lumpsucker, Cyclopterus lumpus, the cod, Gadus morhua and the plaice, Pleuronectes platessa

1983 ◽  
Vol 63 (3) ◽  
pp. 713-723 ◽  
Author(s):  
John Davenport ◽  
Sunniva Lønning ◽  
Elin Kjørsvik
Keyword(s):  
Slow Rate ◽  
Gadus Morhua ◽  
Sea Water ◽  
Ammonia Excretion ◽  
Low Oxygen ◽  
Ovarian Fluid ◽  
Cyclopterus Lumpus ◽  
Metabolic Output ◽  
Eggs And Larvae ◽  
Comparable Size

Cod and plaice eggs show a gradually increasing rate of ammonia excretion during development and in neither species was there a great change in individual output at hatching. The rates of ammonia excretion recorded for cod and plaice larvae were similar to those recorded for planktonic Crustacea of comparable size by Conover & Corner (1968).Lumpsucker eggs and larvae have a basically low rate of ammonia excretion (consistent with their slow rate of development and low oxygen consumption), but much ammonia was released from the eggs in the first day or two after spawning. This ammonia was of non-metabolic origin, but was not accumulated from the ovarian fluid prior to spawning. Lumpfish eggs become very sticky when they are first exposed to sea water, but this stickiness is lost within 24 h. Stickiness stems from a viscous elastic slime; it is suggested that the non-metabolic output of ammonia is caused by changes in the composition of the slime as the eggs are bound together in a lattice.

The effect of copper on the eggs and larvae of plaice and herring

1977 ◽  
Vol 57 (3) ◽  
pp. 849-858 ◽  
Author(s):  
J. H. S. Blaxter
Keyword(s):  
Copper Concentration ◽  
Sea Water ◽  
Larval Mortality ◽  
Sea Bed ◽  
Class Strength ◽  
Comprehensive Survey ◽  
Effect Of Copper ◽  
La Jolla ◽  
Eggs And Larvae

The importance of egg and larval mortality in the determination of year-class strength was discussed at a colloquium at La Jolla, California in 1975 (see Hunter, 1976). In addition to the obvious effects of starvation, predation and disease, pollution by such substances as copper is an important factor affecting viability. The copper concentration in sea water is generally about 1–2,µ/l. Chester & Stoner (1974), in a comprehensive survey, found an average copper concentration of 0.8µ/l in the open ocean and 0.9 µg/l nearer the shore. In British waters Preston et al. (1974) reported a range of 1.1–1.6 µg/l and Portmann (1972a) found a range of 1–20 µg/l with the possibility of 1000 µg/l near sea-bed copper deposits.

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