scholarly journals Modelling seasonal and annual variation in size at functional maturity in the European lobster (Homarus gammarus) from self-sampling data

2009 ◽  
Vol 66 (9) ◽  
pp. 1892-1898 ◽  
Author(s):  
Martial Laurans ◽  
Spyros Fifas ◽  
Sébastien Demaneche ◽  
Stéphane Brérette ◽  
Olivier Debec
Keyword(s):  
Body Size ◽  
Sex Ratio ◽  
Carapace Length ◽  
Annual Variation ◽  
Logistic Function ◽  
Sampled Data ◽  
Functional Maturity ◽  
European Lobster ◽  
Homarus Gammarus ◽  
Northern European

Abstract Laurans, M., Fifas, S., Demaneche, S., Brérette, S., and Debec, O. 2009. Modelling seasonal and annual variation in size at functional maturity in the European lobster (Homarus gammarus) from self-sampling data. – ICES Journal of Marine Science, 66: 1892–1898. Fishers from Le Croisic (France) measure all the lobsters (Homarus gammarus) they capture, indicating their sex and whether the females are ovigerous or non-ovigerous. Between 2003 and 2006 and mainly between April and September, 16 884 lobsters were measured in this manner. These self-sampled data were used to study catchability and functional maturity of lobsters. The sex ratio was 50%, and catchability did not change if a female was ovigerous or non-ovigerous. With the help of a logistic function, a relationship was established between body size and the proportion of ovigerous females. For the study area, 100% of the females were mature upon reaching a carapace length (CL) of 115 mm, and the proportion of ovigerous females reached 70% each year. The L50 value evolved over a CL of 103–106 mm. From the size when 100% of the females matured (115 mm), there was a larger proportion of ovigerous females than in other studies carried out in more northern European areas.

scholarly journals New estimates and complications in the assessment of female functional maturity for the European lobster (Homarus gammarus) on the Yorkshire Coast (UK)

2018 ◽  
Vol 6 (2) ◽  
Author(s):  
James Michael Wood
Keyword(s):  
Functional Maturity ◽  
European Lobster ◽  
Homarus Gammarus

New estimates of female Homarus gammarus functional maturity were developed from targeted offshore and quayside based industry surveys in the Yorkshire Coast fishery. Offshore surveys also provided the first stock specific quantification of pre-recruit contributions. A contrast in results identified a new complication in estimating functional maturity attributed to ‘soft’ animal exploitation which is reviewed and assessed.

scholarly journals Effect of CO<sub>2</sub>-related acidification on aspects of the larval development of the European lobster, <i>Homarus gammarus</i> (L.)

2009 ◽  
Vol 6 (8) ◽  
pp. 1747-1754 ◽  
Author(s):  
K. E. Arnold ◽  
H. S. Findlay ◽  
J. I. Spicer ◽  
C. L. Daniels ◽  
D. Boothroyd
Keyword(s):  
Larval Development ◽  
Carapace Length ◽  
Sea Water ◽  
Marine Ecosystem ◽  
Early Life History ◽  
Magnesium Content ◽  
Marine Animals ◽  
European Lobster ◽  
Homarus Gammarus ◽  
Larval Stages

Abstract. Oceanic uptake of anthropogenic CO2 results in a reduction in pH termed "Ocean Acidification" (OA). Comparatively little attention has been given to the effect of OA on the early life history stages of marine animals. Consequently, we investigated the effect of culture in CO2-acidified sea water (approx. 1200 ppm, i.e. average values predicted using IPCC 2007 A1F1 emissions scenarios for year 2100) on early larval stages of an economically important crustacean, the European lobster Homarus gammarus. Culture in CO2-acidified sea water did not significantly affect carapace length of H. gammarus. However, there was a reduction in carapace mass during the final stage of larval development in CO2-acidified sea water. This co-occurred with a reduction in exoskeletal mineral (calcium and magnesium) content of the carapace. As the control and high CO2 treatments were not undersaturated with respect to any of the calcium carbonate polymorphs measured, the physiological alterations we record are most likely the result of acidosis or hypercapnia interfering with normal homeostatic function, and not a direct impact on the carbonate supply-side of calcification per se. Thus despite there being no observed effect on survival, carapace length, or zoeal progression, OA related (indirect) disruption of calcification and carapace mass might still adversely affect the competitive fitness and recruitment success of larval lobsters with serious consequences for population dynamics and marine ecosystem function.

On the occurrence of juvenile lobster Homarus gammarus in intertidal habitat

2000 ◽  
Vol 80 (2) ◽  
pp. 375-376 ◽  
Author(s):  
Adrian Linnane ◽  
Brendan Ball ◽  
Brian Munday ◽  
John P. Mercer
Keyword(s):  
Carapace Length ◽  
Intertidal Habitat ◽  
Red Sandstone ◽  
European Lobster ◽  
Homarus Gammarus ◽  
Lobster Fishery

The early benthic phase (EBP) European lobster Homarus gammarus, and the habitat to which it recruits, remains largely undiscovered. Following reports that juvenile lobsters were being located within an intertidal lobster fishery in Johnshaven, Scotland, a three day census was undertaken. The shore consisted of a wave cut platform with a red sandstone/cobble conglomerate substratum. Three juvenile lobsters of 28, 32 and 45 mm carapace length (CL) were located in a crevice type habitat. It is hypothesized that in some areas of coastline, intertidal crevices act as a peripheral habitat for juvenile lobsters.

scholarly journals Effect of CO<sub>2</sub>-related acidification on aspects of the larval development of the European lobster, <i>Homarus gammarus</i> (L.)

2009 ◽  
Vol 6 (2) ◽  
pp. 3087-3107 ◽  
Author(s):  
K. E. Arnold ◽  
H. S. Findlay ◽  
J. I. Spicer ◽  
C. L. Daniels ◽  
D. Boothroyd
Keyword(s):  
Larval Development ◽  
Carapace Length ◽  
Sea Water ◽  
Marine Ecosystem ◽  
Early Life History ◽  
Magnesium Content ◽  
Marine Animals ◽  
European Lobster ◽  
Homarus Gammarus ◽  
Larval Stages

Abstract. Oceanic uptake of anthropogenic CO2 results in a reduction in pH termed "Ocean Acidification" (OA). Comparatively little attention has been given to the effect of OA on the early life history stages of marine animals. Consequently, we investigated the effect of culture in CO2-acidified sea water (approx. 1200 ppm, i.e. average values predicted using IPCC 2007 A1F1 emissions scenarios for year 2100) on early larval stages of an economically important crustacean, the European lobster Homarus gammarus. Culture in CO2-acidified sea water did not significantly affect carapace length or development of H. gammarus. However, there was a reduction in carapace mass during the final stage of larval development in CO2-acidified sea water. This co-occurred with a reduction in exoskeletal mineral (calcium and magnesium) content of the carapace. As the control and high CO2 treatments were not undersaturated with respect to any of the calcium carbonate polymorphs measured, the physiological alterations we record are most likely the result of acidosis or hypercapnia interfering with normal homeostatic function, and not a direct impact on the carbonate supply-side of calcification per se. Thus despite there being no observed effect on survival, carapace length, or zoeal progression, OA related (indirect) disruption of calcification and carapace mass might still adversely affect the competitive fitness and recruitment success of larval lobsters with serious consequences for population dynamics and marine ecosystem function.

The polychaete Histriobdella homari and major groups of epibionts on the European lobster, Homarus gammarus and other decapods

Crustaceana ◽  
2019 ◽  
Vol 92 (2) ◽  
pp. 189-203
Author(s):  
Vidar Øresland
Keyword(s):  
Carapace Length ◽  
Homarus Americanus ◽  
Parasitic Copepod ◽  
Analytic Method ◽  
Quantitative Biology ◽  
European Lobster ◽  
Homarus Gammarus ◽  
First Time

Abstract The quantitative biology and ecology of epibiotic communities on decapods are only vaguely known. An analytic method revealed close to 100% of metazoan epibionts among the eggs and gills of some decapods in Swedish waters. High abundances of the epibiotic polychaete Histriobdella homari were found (100% prevalence) and European lobsters, Homarus gammarus, with a carapace length of 100 mm have, as a mean, approx. 6700 H. homari among their old eggs, underlining the importance of these epibiont polychaetes as cleaners of lobster eggs (and gills). For the first time, a nematode (Pontonema sp.) was found feeding on H. homari. Gills of American lobsters, Homarus americanus, caught in Swedish waters were infested with the European parasitic copepod Nicothoe astaci (80% prevalence). This study shows that on decapods a number of epibionts (Ciliophora, Nematoda, Hydrachnidia, Copepoda, Ostracoda, Amphipoda and Kinorhyncha) can be quantified, using the method adopted here, which will enable a better understanding of epibiotic communities.

Body size and sex ratio in emergent stonefly nymphs (Isogenoides olivaceus: Perlodidae): variation between cohorts and populations

1994 ◽  
Vol 72 (8) ◽  
pp. 1371-1375 ◽  
Author(s):  
Roger J. Haro ◽  
Kay Edley ◽  
Michael J. Wiley
Keyword(s):  
Body Size ◽  
Sex Ratio ◽  
Annual Variation ◽  
Sexual Size Dimorphism ◽  
Population Regulation ◽  
Size Variation ◽  
Size Distributions ◽  
Ecological Significance ◽  
Male Size ◽  
Animal Size

The ecological significance of pattern in animal-size distribution has been receiving increased scrutiny in studies of population regulation and individual energetics. However, few studies have assessed differences in size variation between sequential generations or adjacent populations. Annual variation in body size and sex ratio of emergent perlodid stonefly nymphs, Isogenoides olivaceus (Frison) (Plecoptera: Perlodidae), were examined in populations from two Michigan mesic groundwater rivers. Final nymphal body size was estimated from sex-specific length to mass regression relationships using exuviae collected from each site. Sexual size dimorphism accounted for much of the intraspecific size variation within both populations and cohorts: females were larger ([Formula: see text]) than males ([Formula: see text]). Males showed less size variation than females; unlike those for females, size distributions for males were significantly skewed. Secondary sex ratios were female biased in both populations and all cohorts and ranged between 59.1 and 72.8%. Female sex bias increased with relative male size in both populations.

Population estimate and body size of European pond turtles (Emys orbicularis) from Pazarağaç (Afyonkarahisar/Turkey)

Biologia ◽  
2007 ◽  
Vol 62 (2) ◽  
Author(s):  
Dinçer Ayaz ◽  
Uwe Fritz ◽  
Cemal Tok ◽  
Ahmet Mermer ◽  
Murat Tosunoğlu ◽  
...  
Keyword(s):  
Body Size ◽  
Sex Ratio ◽  
Confidence Interval ◽  
Population Size ◽  
Body Mass ◽  
Carapace Length ◽  
Population Estimate ◽  
Emys Orbicularis ◽  
Adult Sex Ratio ◽  
Almost All

AbstractData on population size, adult sex ratio, body size and mass are provided for a population of the turtle Emys orbicularis near Pazarağaç (Afyonkarahisar/Turkey). Using the mark-recapture method (triple catch), a population size of 664 turtles was estimated (95% confidence interval, range 332–996), corresponding to a density of 83 turtles per hectare (range 41.5–124.5). The adult sex-ratio was significantly skewed in favor of males (2.02 males: 1 female; P < 0.001). Almost all recorded specimens were adult (98.1%). Mean straight carapace length (SCL) and body mass (BM) of adult turtles were: SCL = 128.65 mm, BM = 345 g for males (n = 168) and SCL = 135.37 mm, BM = 463 g for females (n = 83).

Maturity, fecundity and reproductive potential of the European lobster (Homarus gammarus) in Ireland

2001 ◽  
Vol 81 (1) ◽  
pp. 61-68 ◽  
Author(s):  
O. Tully ◽  
V. Roantree ◽  
M. Robinson
Keyword(s):  
Egg Size ◽  
Carapace Length ◽  
Reproductive Potential ◽  
Size Class ◽  
Size At Maturity ◽  
Maturity Models ◽  
Physiological Maturity ◽  
European Lobster ◽  
Size Classes ◽  
Homarus Gammarus

Fecundity and size at maturity of the European lobster Homarus gammarus (Crustacea: Decapoda) was estimated in four coastal regions of Ireland. Egg size increased with carapace length (CL) (egg size=0·9939×ln (CL)−3·0809). The size–fecundity relationship for all coasts combined was (fecundity=0·0044×CL3·1554).  Physiological maturity was assessed using ovary colour, ovary factor, ova size, abdomen width/CL ratio, cement gland activity and moult status as criteria. Size at 50% maturity varied from 92·5 to 96  mm depending on region. The size–maturity relationship for all coasts combined was (Maturity= 1/(1+exp(14·595−0·15598×CL))). Over 60% of lobsters in the commercial landings were under the size at 50% maturity.  Relative reproductive potential (RRP) of different size-classes was calculated from the size–fecundity and size–maturity models and the numbers by length in the landings. The modal RRP size-class was 98–100 mm. The commercial landings were dominated by the 86–92  mm size-classes.

The reaction of European lobster larvae (Homarus gammarus) to different quality food: effects of ontogenetic shifts and pre-feeding history

Oecologia ◽  
2013 ◽  
Vol 174 (2) ◽  
pp. 581-594 ◽  
Author(s):  
Katherina L. Schoo ◽  
Nicole Aberle ◽  
Arne M. Malzahn ◽  
Isabel Schmalenbach ◽  
Maarten Boersma
Keyword(s):  
Food Effects ◽  
European Lobster ◽  
Ontogenetic Shifts ◽  
Homarus Gammarus ◽  
Quality Food
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