Cholesterol Requirements of Juvenile American Lobster (Homarus americanus)

1975 ◽  
Vol 32 (8) ◽  
pp. 1431-1435 ◽  
Author(s):  
John D. Castell ◽  
Edgar G. Mason ◽  
Jane F. Covey
Keyword(s):  
Brine Shrimp ◽  
Control Diet ◽  
Dietary Cholesterol ◽  
Dry Weight ◽  
Homarus Americanus ◽  
American Lobster ◽  
Cod Liver Oil ◽  
Mineral Salts ◽  
Growth And Survival ◽  
Feeding Trials

In preliminary feeding trials with juvenile American lobsters (Homarus americanus) there were some differences in growth and survival that appeared to be related to deletion or addition of cod liver oil, mineral salts, vitamins, and glucosamine. However, the results were questionable due to deficiency of dietary cholesterol. Only when 1% cholesterol was added to the control diet was growth and survival achieved similar to that of lobsters fed brine shrimp. The optimum or required level of cholesterol was found to be approximately 0.5% of the dry weight of the diet.

Embryonic Development and Energetic Investment in Egg Production in Relation to Size of Female Lobster (Homarus americanus)

1987 ◽  
Vol 44 (6) ◽  
pp. 1157-1164 ◽  
Author(s):  
Jean Attard ◽  
Christiane Hudon
Keyword(s):  
Embryonic Development ◽  
Egg Production ◽  
Energy Content ◽  
Larval Growth ◽  
Somatic Growth ◽  
Dry Weight ◽  
Homarus Americanus ◽  
Female Size ◽  
Growth And Survival ◽  
The Difference

The egg development index, dry weight, and energy content were measured on eggs from 148 ovigerous female lobsters (Homarus americanus) caught off îles de la Madeleine (Québec). Two modes of embryonic development were observed at stages 3 and 8 (Perkins. 1972. Fish. Bull. 70: 95–99). Stage 3 predominated among females of 71–82 mm and stage 8 among those of 83–110 mm carapace length (CL), indicating that larger females both extrude and hatch their eggs earlier than smaller females. Energy content per egg increased with female size and ranged from 4.6 cal∙egg−1 for females 72–76 mm CL to 5.2 cal∙egg−1 for females 107–110 mm CL. Females between 82 and 90 mm CL invested 0.155 kcal per gram of their own weight in egg production, which was the maximum value in the size range. Females smaller than 82 mm CL and larger than 90 mm CL expended proportionately less on egg production, with the difference allocated to either somatic growth in the smaller or maintenance in the larger animals. Large females produce proportionately more eggs, containing more calories per egg which hatch at an earlier time than small females. The higher energy content of eggs from large females and their earlier hatching are probably factors that enhance larval growth and survival. If so, large females contribute relatively more to recruitment than their greater fecundity.

Effects of dietary DHA and EPA on neurogenesis, growth, and survival of juvenile American lobster,Homarus americanus

2009 ◽  
Vol 43 (1) ◽  
pp. 225-232 ◽  
Author(s):  
Gro van der Meeren ◽  
Michael F. Tlusty ◽  
Anita Metzler ◽  
Terje van der Meeren
Keyword(s):  
Homarus Americanus ◽  
American Lobster ◽  
Growth And Survival

Survival and Growth of Juvenile American Lobsters (Homarus americanus) After Eyestalk Ablation

1979 ◽  
Vol 36 (1) ◽  
pp. 93-97 ◽  
Author(s):  
D. J. Trider ◽  
E. G. Mason ◽  
J. D. Castell
Keyword(s):  
Weight Gain ◽  
Brine Shrimp ◽  
Homarus Americanus ◽  
American Lobster ◽  
Eyestalk Ablation ◽  
Adequate Diet ◽  
Stage Juvenile ◽  
Survival And Growth ◽  
The Mean ◽  
And Control

The effect of size at the time of ablation on postoperative survival was assessed by removing the eyestalk from 4th, 5th, and 6th stage juvenile American lobsters (Homarus americanus) 6 d postmolt. The 6th stage juveniles exhibited significantly higher survival (72.8%) through three postoperative molts than the 5th or 4th stage lobsters (45 and 30% survival, respectively). Survival of control lobsters through the same number of molts was 90%. The feeding of a nutritionally adequate diet (frozen brine shrimp) was of prime importance with regard to survival of both ablated and control lobsters. The mean percent total weight gains for these three postablation molts were 610, 571, and 642% for 4th, 5th, and 6th stage lobsters, respectively, while the weight gain for control lobsters was 407%. The data suggest that eyestalk ablation should not be performed earlier than 6th stage for maximum survival and growth. Key words: eyestalk ablation, American lobster, survival, growth

Environmentally mediated crowding effects on growth, survival and metabolic rate of juvenile American lobsters (Homarus americanus)

2001 ◽  
Vol 52 (8) ◽  
pp. 1157 ◽  
Author(s):  
Richard A. Wahle ◽  
Oliver Tully ◽  
Vera O'Donovan
Keyword(s):  
Treatment Effects ◽  
Field Experiments ◽  
Homarus Americanus ◽  
Geographic Range ◽  
Physiological Age ◽  
Large Temperature ◽  
American Lobster ◽  
Age Classes ◽  
Growth And Survival ◽  
Per Capita

The geographic range of the American lobster spans a very large temperature gradient. The gradient’s effects on growth and the onset of maturity are well known, but young age classes restricted to nursery grounds tend to overlap more in cooler regions than in warm regions, and the resulting effects on growth and survival are poorly understood. In field experiments in enclosures, in Maine, USA, age-0+ lobsters grew more slowly at the cooler site, and growth was little affected by stocking treatment. At the warmer site, stocking treatment effects were more pronounced. Sites did not differ in per capita survival, and stocking treatment effects were equally pronounced at the two: survival of 0+ lobsters was unaffected by additions of 1+ lobsters, but was significantly adversely affected by the addition of 0+ lobsters. Mass-specific metabolic rates of similar sized lobsters averaged higher at the cooler site. Our results suggest that location and intercohort effects are likely to affect growth more than survival of newly settled lobsters and that juveniles compensate metabolically for cool temperatures but not enough to compensate completely for their growth-retarding effects. Spatial variability in temperature may complicate use of physiological age indicators for the American lobster and other temperate crustaceans.

Growth of juvenile American lobster Homarus americanus in a changing environment

2016 ◽  
Vol 557 ◽  
pp. 177-187 ◽  
Author(s):  
MD McMahan ◽  
DF Cowan ◽  
Y Chen ◽  
GD Sherwood ◽  
JH Grabowski
Keyword(s):  
Homarus Americanus ◽  
American Lobster ◽  
Changing Environment

Predicting bycatch hotspots based on suitable habitat derived from fishery-independent data

2020 ◽  
Vol 641 ◽  
pp. 159-175
Author(s):  
J Runnebaum ◽  
KR Tanaka ◽  
L Guan ◽  
J Cao ◽  
L O’Brien ◽  
...  
Keyword(s):  
Habitat Suitability ◽  
Mixed Model ◽  
Linear Mixed Model ◽  
Gulf Of Maine ◽  
Homarus Americanus ◽  
Management Tool ◽  
American Lobster ◽  
Suitable Habitat ◽  
Climate Conditions ◽  
Suitability Index

Bycatch remains a global problem in managing sustainable fisheries. A critical aspect of management is understanding the timing and spatial extent of bycatch. Fisheries management often relies on observed bycatch data, which are not always available due to a lack of reporting or observer coverage. Alternatively, analyzing the overlap in suitable habitat for the target and non-target species can provide a spatial management tool to understand where bycatch interactions are likely to occur. Potential bycatch hotspots based on suitable habitat were predicted for cusk Brosme brosme incidentally caught in the Gulf of Maine American lobster Homarus americanus fishery. Data from multiple fisheries-independent surveys were combined in a delta-generalized linear mixed model to generate spatially explicit density estimates for use in an independent habitat suitability index. The habitat suitability indices for American lobster and cusk were then compared to predict potential bycatch hotspot locations. Suitable habitat for American lobster has increased between 1980 and 2013 while suitable habitat for cusk decreased throughout most of the Gulf of Maine, except for Georges Basin and the Great South Channel. The proportion of overlap in suitable habitat varied interannually but decreased slightly in the spring and remained relatively stable in the fall over the time series. As Gulf of Maine temperatures continue to increase, the interactions between American lobster and cusk are predicted to decline as cusk habitat continues to constrict. This framework can contribute to fisheries managers’ understanding of changes in habitat overlap as climate conditions continue to change and alter where bycatch interactions could occur.

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