The biology of Calocaris macandreae [Crustacea: Thalassinidea]

1963 ◽  
Vol 43 (3) ◽  
pp. 729-747 ◽  
Author(s):  
John B. Buchanan
Keyword(s):  
Growth Rate ◽  
Survival Curve ◽  
Age Groups ◽  
Larval Survival ◽  
Egg Laying ◽  
Moult Cycle ◽  
Size Frequency Distribution ◽  
Apparent Lack ◽  
Slowing Down ◽  
Population Numbers

Previous work on the biology and distribution of Calocaris is discussed briefly. The distribution in Northumberland waters is considered in relation to depth and bottom sediment.Quantitative monthly samples show that population numbers remain very stable throughout the year. A well marked egg-laying period occurs in January-February when relatively few eggs (average 38) are attached to the pleopods. Eggs are carried for 8–9 months and hatch in September-October. By a combination of size-frequency distribution and gonad-developmnt classification the age-groups in the population are interpreted. After passing through a phase of testes development and spermatophore formation individuals lay their first batch of eggs at the end of the 5th year. The ovaries regenerate over a 2-year period and a second egg-laying takes place at the end of the 7th year with a possible third at the end of the 9th year. The incidence of soft individuals in the samples together with observed changes in the coverage with epifaunistic growths indicate that after entering the 5th year a single annual moult cycle begins with a slowing down in growth rate.Population numbers, fecundity and larval survival are discussed. Both the survival curve and the apparent lack of serious predation suggest that the population reaches senescence

The effect of infection with Schistosoma margrebowiei on the growth of Bulinus natalensis

1993 ◽  
Vol 67 (1) ◽  
pp. 10-16 ◽  
Author(s):  
K. Raymond ◽  
A. J. Probert
Keyword(s):  
Growth Rate ◽  
Age Groups ◽  
Egg Laying ◽  
Uninfected Control ◽  
Control Groups ◽  
Post Exposure ◽  
Patent Infection

AbstractThree age groups of Bulinus natalensis, immature, mature but not yet egg-laying and mature egg-laying, were infected with miracidia of Schistosoma margrebowiei. The growth of infected, exposed but showing no signs of infection, and uninfected control groups, were examined at weekly intervals for ten weeks post exposure. Snails exposed to infection when immature, even in the group where no patent development ensued, showed a statistically significant reduction in growth and this was evident as early as 2–5 weeks post exposure. When infection occurred at the stage prior to egg-laying a significant reduction in growth was seen but only in the group which developed a patent infection. This was also the case for the egg-laying group although the reduction in growth was only significant in the final three weeks of the experiment. Thus in all three age groups, growth rate was reduced and the infected snails were significantly smaller at the end of ten weeks compared with the controls. The reasons for these effects are discussed.

scholarly journals Growth analysis of chub, Leuciscus cephalus (L.), and dace, Leuciscus leuciscus (L.), in the Úpoř stream using growth data of recaptured marked fish

2011 ◽  
Vol 50 (No. 7) ◽  
pp. 329-339 ◽  
Author(s):  
P. Vlach ◽  
J. Dušek ◽  
M. Švátora ◽  
P. Moravec
Keyword(s):  
Growth Rate ◽  
Age Groups ◽  
Growth Equation ◽  
Growth Data ◽  
Average Value ◽  
Slowing Down ◽  
Length Growth ◽  
Weight Relationship ◽  
Average Condition ◽  
The Mean

The length growth of chub and dace was observed. The scale method was used as well as data gained from recaptured individuals which were marked with visible elastomer tags and platinum wire tags with a coloured code placed under the first bony ray of the dorsal fin. The length-weight relationship for chub could be explained by the equation w = 0.00001.l <sup>3.067</sup> (r<sup>2</sup> = 0.96). The average condition coefficient reached 1.49. The growth was balanced, gradually slowing down. Von Bertallanffy growth equation had the form L<sub>t </sub>= 245.47(1 &ndash; e<sup>&ndash;0.206(t + 0.0333)</sup>). The average value of instantaneous monthly growth rate (G<sub>m</sub>) ranged between 0.4 and 4.3 (in %). Mean G<sub>m</sub> of particular age groups gradually decreased. G<sub>m</sub> varied seasonally, annually and in different parts of the stream. The length-weight relationship for dace was w = 0.000009.1<sup>3.0948 </sup>(r<sup>2</sup> = 0.97). The mean condition coefficient reached the value of 1.11. The length growth was balanced, gradually decreasing. Von Bertallanffy equation had the form L<sub>t</sub> = 216.28(1 &ndash; e<sup>&ndash;0.2536(t + 0.26094)</sup>). The instantaneous monthly growth rate ranged between &ndash;1.57 and 10.38 (in percentage). This indicator fluctuated according to the age, season and year. &nbsp;

Age, growth, and reproduction of the rock goby, Gobius paganellus L., in the Isle of Man

1961 ◽  
Vol 41 (3) ◽  
pp. 737-769 ◽  
Author(s):  
P. J. Miller
Keyword(s):  
Breeding Season ◽  
Sexual Maturity ◽  
Survival Curve ◽  
Age Groups ◽  
Maximum Size ◽  
Gonad Maturation ◽  
Corpora Lutea ◽  
Size Frequency Distribution ◽  
Isle Of Man ◽  
Growth And Reproduction

SUMMARYAge, growth and reproduction of the intertidal teleost, Gobius paganellus, has been investigated in the Isle of Man from March 1959 to September 1960. Samples were obtained by poisoning shore pools with a rotenone emulsion.Age was determined by examination of otoliths where a translucent annual ring is laid down in spring. Although the potential life span is at least 10 years, immature fishes of the first two age-groups constitute most of the population. An onshore breeding migration is postulated. An empirical survival curve indicates a high mortality rate during the first two years of life. Instances of predation on G. paganellus are given.Growth in length is logarithmic, with marked decrease in growth rate from about the age of sexual maturity. During the year, growth occurred from June to October. Maximum standard lengths recorded were 92*5 mm (feThe overall sex ratio of females to males was 1:1-326; this predominance of males persisted through the age-groups. The reproductive organs are briefly described, and a classification of gonad maturation is proposed. The breeding season lasted from mid-April to mid-June. Sexual maturity was reached at the end of the second or third year of life. Smallest ripening individuals found were 48-5 mm (female) and 505 (male). Fecundity increased with body size. Eggs were deposited on stones in shore pools and guarded by the male. Post-larvae occurred in pools from the beginning of July, and the first demersal individuals from August. Size-frequency distribution of oocytes in the ovary indicates that at least two broods may be produced in a single breeding season.In maximum size, longevity, and age at maturity, G. paganellus differs from other European gobies so far studied. It is suggested that a similar life history is exhibited by other British species of Gobius. The short breeding season of G. paganellus in the Isle of Man is held to be a result of proximity to the northern limit of distribution of this species. Examples of this phenomenon in other teleosts are provided. The significance of pre-ovulatory corpora lutea in the ovary of G. paganellus is briefly discussed.

Time-Energy Budgets During Reproduction and the Evolution of Single Parenting in the Superb Lyrebird

1986 ◽  
Vol 34 (3) ◽  
pp. 351 ◽  
Author(s):  
A Lill
Keyword(s):  
Growth Rate ◽  
Brood Size ◽  
Slow Growth ◽  
Bird Species ◽  
Egg Laying ◽  
Energy Budgets ◽  
Brood Care ◽  
Single Parenting ◽  
Slow Growth Rate ◽  
Small Brood

Estimated expenditures on brood-care by unassisted female superb lyrebirds, obtained through time-energy budgeting, were compared with published values for other bird species. With the exception of nestbuilding, estimated daily expenditures were relatively low, due mainly to the small brood size and low level of parental attentiveness. It is suggested that the traits which reduce daily brood-care expenditures, particularly the small brood size and extremely slow growth rate, may have evolved as adaptations which enabled deserted females operating close to maximal capacity to cope with single-parenting. Male parental involvement could probably increase the growth rate of the young, but not brood size; moreover, egg- laying was sufficiently asynchronous to afford multiple mating opportunities to parentally emancipated males. However, the slow growth rate of the young results in relatively large overall brood-care expenditures for females. Investments by males of up to 50% of daylight hours and 45% of BMR on singing at the height of the mating season were comparable with those of partially emancipated, polygynous males of other species. They probably reflect the high level of competition to control good display areas and to advertise status and quality to widely spaced females.

Biology, Management, and Protection of North American Sturgeon

2002 ◽  
Keyword(s):  
Growth Rate ◽  
Incubation Temperature ◽  
Larval Survival ◽  
Sampling Time ◽  
White Sturgeon ◽  
Green Sturgeon ◽  
Acipenser Medirostris ◽  
Relative Growth ◽  
Klamath River ◽  
Length Relationship

<em>Abstract.</em>—Gametes of green sturgeon <em>Acipenser medirostris</em> (caught in the Klamath River, California) and farm-reared white sturgeon <em>A. transmontanus</em> were obtained using hormonal induction of ovulation and spermiation. The offspring of one female in each species were reared in the laboratory, to compare their development and growth. Green and white sturgeon embryos had similar rates of development and hatched after 169 h and 176 h, respectively, at incubation temperature 15.7 ± 0.2°C. Embryos of both species exhibited similar holoblastic development and passed through 36 stages characteristic of acipenserids. Green sturgeon fertilization and hatching rates were 41.2% and 28.0%, compared with 95.4% and 82.1% for the white sturgeon. Larval survival to 45 d (metamorphosis) was 93.3% in green and 92.1% in white sturgeon. Newly hatched green sturgeon (length 13.7 ± 0.4 mm, mean ± SD) were larger and less pigmented, compared with white sturgeon. They had large ovoid yolk sacs and did not exhibit pelagic behavior that was observed in white sturgeon. The onset of exogenous feeding in green sturgeon occurred at age 10–15 d and length 24.0 ± 0.5 mm, and metamorphosis was completed at age 45 d and length 74.4 ± 5.9 mm (rearing temperature 18.5 ± 0.2°C). Weight and length of green sturgeon larvae and juveniles were considerably greater than in white sturgeon at each sampling time, but the relative growth rate and weight-length relationship were similar in both species. This suggests an effect of larger egg size and maternal yolk supply on the growth of green sturgeon. We conclude that green sturgeon differs from the white sturgeon in their reproductive strategy and, potentially, reproductive habitat.

Annual Productivity and Its Measurement in a Multi-Brooded Passerine, the Eastern Bluebird

The Auk ◽  
1979 ◽  
Vol 96 (3) ◽  
pp. 562-572
Author(s):  
Benedict C. Pinkowski
Keyword(s):  
Success Rate ◽  
Age Groups ◽  
Nesting Success ◽  
Egg Laying ◽  
Success Rates ◽  
Sialia Sialis ◽  
Eastern Bluebird ◽  
Annual Productivity ◽  
Eastern Bluebirds ◽  
Breeding Seasons

Abstract Breeding and demographic parameters are examined for 434 Eastern Bluebirds (Sialia sialis) attempting 324 nests in southeastern Michigan during 1968-1977. Nesting birds spent an average of 10.4 weeks (63.9% of a 16.2-week season) in the study area. Only 154 (35.5%) of the nesting birds remained for entire breeding seasons; these season-long residents averaged 2.14 nests/season and had a higher success rate (68.4%) and presumably greater productivity (5.6 young · pair−1 · season −1) than other birds because site fidelity depends on nesting success. Although two seasonal peaks for egg-laying were observed, only 75 of 357 birds (21.0%) successfully raised two broods. Evidence is presented to suggest that birds observed for only part of a season initiated nests at the same rate while in and not in the study area, so that an average annual productivity value of 5.0 young · pair−1 · season −1 is calculated for all nesting birds from the observed success rate (57.1%) and mean length of stay in the area. Estimated average productivity of yearlings (4.3 young · pair−1 · season −1) was lower than that of adults (5.7 young · pair−1 · season −1) although nesting success rates were similar in the two age groups.

The early bird catches the worm: age-specific arrival time influences reproductive performance in the White Stork Ciconia ciconia

Bird Study ◽  
2019 ◽  
Vol 66 (1) ◽  
pp. 121-129
Author(s):  
Bourhane-Eddine Belabed ◽  
Mohammed Athamnia ◽  
Laïd Touati ◽  
Farrah Samraoui ◽  
Abdennour Boucheker ◽  
...  
Keyword(s):  
Reproductive Performance ◽  
Age Groups ◽  
Egg Laying ◽  
White Stork ◽  
Laying Date ◽  
First Year ◽  
Arrival Date ◽  
Breeding Colony ◽  
Ciconia Ciconia ◽  
The Impact

<sec><title>Capsule</title>Age, arrival date and egg laying date are essentially closely related and determine reproductive performance in the White Stork Ciconia ciconia.</sec><sec><title>Aims</title>To describe the impact of age, arrival date and egg laying date on breeding success in the White Stork.</sec><sec><title>Methods</title>Ringing data from a White Stork breeding colony of 212 nests at Dréan, Algeria, were used to model the relationship between age, arrival date, laying date and reproductive performance. Seventy breeders that were individually colour-ringed as nestlings were monitored.</sec><sec><title>Results</title>Birds breeding on the periphery of the colony had significantly smaller nests and showed a tendency towards later laying dates, but they did not differ from centrally nesting birds in age or arrival date. First year birds did not breed and second year birds were significantly more likely than older age groups to occupy nests but fail to lay eggs. Older birds arrived earlier at the breeding colony and had a higher probability of initiating laying than younger birds. They also had a higher probability of nesting successfully and fledging a larger number of young.</sec><sec><title>Conclusion</title>Age determined arrival and laying dates and influenced breeding performance in the White Stork.</sec>

Sign in / Sign up

Export Citation Format

Share Document