The Growth Rate of the American Lobster (Homarus americanus)

1953 ◽  
Vol 10 (7) ◽  
pp. 371-412 ◽  
Author(s):  
D. G. Wilder
Keyword(s):  
Carapace Length ◽  
Growing Season ◽  
Homarus Americanus ◽  
American Lobster ◽  
Maritime Provinces ◽  
Larval Stages ◽  
Total Length ◽  
Straight Line ◽  
Size Groups ◽  
Stage 1

Carapace measurements of lobster larvae caught in the western part of Northumberland Strait showed that in this area the natural growth in length per moult is 34.4 per cent from stage 1 to stage 2, 31.8 per cent from stage 2 to 3, and 30.3 per cent from stage 3 to 4. The seasonal distribution of the first four larval stages was determined from plankton tows made continuously from mid-June to late September each year from 1948 to 1952. To determine natural annual growth, lobsters of 15 to 25 cm., total length, were sorted into five or six size groups and were distinctively marked by means of holes punched through the tail fan. These were liberated on six widely separated fishing grounds in the Maritime Provinces. Recoveries of these marked lobsters four to twelve months after release showed that in the southern Gulf of St. Lawrence, 15- to 20-cm. lobsters grew 8 to 9 mm. (13 to 15 per cent) in carapace length, 22 to 25 mm. (13 to 14 per cent) in total length and 80 to 95 grams (45 to 53 per cent) in weight. In southern Nova Scotia and Grand Manan 20- to 25-cm. lobsters grew 10 to 12 mm. (13 to 15 per cent) in carapace length, 27 to 34 mm. (12 to 15 per cent) in total length and 170 to 220 grams (43 to 54 per cent) in weight. From the carapace length of 4th-stage larvae and straight-line equations relating carapace length before moulting and carapace length after moulting, the average carapace lengths of lobsters in stages 5 to 20 were calculated. From observations and calculations on the growth per moult and moulting frequency, it is estimated that in the Northumberland Strait area lobsters reach a length of 14 cm. (51/2 in.) at the end of the fifth growing season (41/4 years old) and 24 cm. (91/2 in.) at the end of the ninth growing season (81/4 years).

Influence of settlement time and size on postsettlement growth in the American lobster (Homarus americanus)

1998 ◽  
Vol 55 (11) ◽  
pp. 2436-2446 ◽  
Author(s):  
Mary-Jane James-Pirri ◽  
J Stanley Cobb ◽  
Richard A Wahle
Keyword(s):  
Carapace Length ◽  
Growing Season ◽  
Homarus Americanus ◽  
Growth Trajectories ◽  
First Year ◽  
American Lobster ◽  
Late Season ◽  
Mean Size ◽  
Growth Profiles ◽  
Settlement Time

We investigated the size and timing of settlement of postlarval (fourth instar) American lobster (Homarus americanus) and the size attained by the end of the first growing season. Mean size and duration of benthic instars (IV-XI) were obtained from a field growth experiment. Lobsters settling in early- and mid-season were larger at each instar and had different growth profiles than late-season settlers. In particular, the rate of growth at the fifth and sixth instar transition was greater for early- and mid-season settlers than for late-season settlers. Postlarvae settling early reached the ninth instar sooner than mid- or late-season settlers. Estimates of size and intermolt duration of each instar for early- and late-season postlarvae were applied to planktonic postlarval data (1988-1995) to estimate growth trajectories during the first year. For all years, postlarvae present early in the season were 30-50% larger (carapace length) and two or three instars further developed than late settlers by the end of the growing season. Estimates of size attained by the end of the 1994 growing season matched field-collected benthic size frequency data for this same year. Although initial carapace length at settlement was important, the timing of settlement was more influential on the size attained by the end of the first growing season.

An automatic feeding device and the use of live and frozen Artemia for culturing larval stages of the American lobster, Homarus americanus

Aquaculture ◽  
1974 ◽  
Vol 3 (3) ◽  
pp. 311-314 ◽  
Author(s):  
Steven A. Serfling ◽  
Jon C. Van Olst ◽  
Richard F. Ford
Keyword(s):  
Homarus Americanus ◽  
American Lobster ◽  
Larval Stages

Intermolt Insemination, an Alternative Mating Strategy for the American Lobster (Homarus americanus)

1990 ◽  
Vol 47 (12) ◽  
pp. 2402-2406 ◽  
Author(s):  
S. L. Waddy ◽  
D. E. Aiken
Keyword(s):  
Reproductive Strategy ◽  
Carapace Length ◽  
Homarus Americanus ◽  
Mating Strategy ◽  
American Lobster ◽  
Male Aggression ◽  
Female Receptivity ◽  
Molt Stage ◽  
Alternative Mating Strategy ◽  
Ovarian Stage

American lobster (Homarus americanus) have a dual mating strategy. Although most females mate when they are newly molted, mating can occur at any molt stage if necessary, in the laboratory, virtually all uninseminated preovigerous females mate prior to spawning. Male aggression is a major factor in the success of intermolt mating and males can discriminate between immature and mature females, and between inseminated and uninseminated females. Female receptivity is affected by both ovarian stage and the presence of stored sperm, but not by molt stage. Most females become unreceptive after insemination, but their receptivity returns once the supply of stored sperm is exhausted. Intermolt mating occurs in smaller lobster that for some reason did not mate at molt, and it is an important part of the reproductive strategy of larger lobster. Lobster s[Formula: see text] carapace length frequently spawn twice without molting and often fail to store sufficient sperm to fertilize consecutive spawnings. Intermolt mating ensures these females will produce fertile second broods.

THE EFFECTS OF CRUDE OIL ON LARVAE OF LOBSTER HOMARUS AMERICANUS

1977 ◽  
Vol 1977 (1) ◽  
pp. 569-573
Author(s):  
Joseph M. Forns
Keyword(s):  
Crude Oil ◽  
Mass Culture ◽  
Homarus Americanus ◽  
Behavioral Characteristics ◽  
American Lobster ◽  
Larval Stages ◽  
Fourth Larval Stage ◽  
Flow Through ◽  
Oil Exposure ◽  
South Louisiana

ABSTRACT The effects of API reference South Louisiana crude oil upon four larval stages of American lobster (Homarus americanus) were determined in a flow-through system. Tests were conducted with naturally-hatched animals in individual test chambers as well as in mass culture systems in an operating state lobster hatchery. Experimental flow-through crude oil exposure concentrations were 0.1, and 1.0 ppm, administered as a strongly-agitated emulsion-like mix to ambient temperature seawater ranging from 15°-20°C. Oil exposure residence times ranged from 0.8-5.6 minutes depending on the test. Exposed animals were monitored six times daily for feeding behavioral characteristics, mobility, molting success, growth and development times to reach the fourth larval stage. Pigmentation analysis was performed on individual larvae by photomicroscopy, and hydrocarbon analyses were also conducted thereon. Post-larval development through the eighth stage was investigated. Statistical comparisons were made among different control animals and between control and oil-exposed larvae.

Swimming Ability of Larval American Lobsters, Homarus americanus, in Flowing Water

1986 ◽  
Vol 43 (11) ◽  
pp. 2177-2183 ◽  
Author(s):  
G. P. Ennis
Keyword(s):  
Stage Iv ◽  
Homarus Americanus ◽  
American Lobster ◽  
Flowing Water ◽  
Swimming Ability ◽  
Flow Rates ◽  
Larval Stages ◽  
Upstream Direction ◽  
Swimming Capacity ◽  
Observation Period

The swimming capacity of American lobster, Homarus americanus, larvae in flowing water was observed in a screened-off portion of a flow tank. At a flow rate of 2 cm∙s−1, stage I–III larvae were swimming for 46–74% of the observations during the first 5 min but this ranged from 0 to 28% toward the end of a 30-min period. At higher flow rates, however, very few of these larvae were able to continue swimming longer than 5 min. Newly molted stage IV larvae displayed substantially improved swimming ability compared with earlier stages. At 2 cm∙s−1, these larvae were swimming for 40–48% of the observations over the 30-min period, although at higher flow rates their capacity to continue swimming was also limited and few were observed swimming longer than 10 min. Older stage IV larvae were more capable swimmers than newly molted stage IV larvae and displayed a capacity to continue swimming over the 30-min observation period at flow rates up to 9 cm∙s−1. In flowing water, the frequency of orientation in the upstream direction for larvae that were swimming was higher than for control larvae. For stage IV larvae especially, this frequency was higher at the higher flow rates. The observations demonstrate the presence of a rheotactic response in all larval stages of the American lobster. The response is relatively weak in stages I–III but strong in stage IV.

Lethal and Sublethal Toxicity of Drilling Fluids to Larvae of the American Lobster, Homarus americanus

1984 ◽  
Vol 41 (9) ◽  
pp. 1334-1340 ◽  
Author(s):  
Jennifer G. Smith Derby ◽  
Judith M. Capuzzo
Keyword(s):  
Sublethal Effects ◽  
Drilling Fluid ◽  
Homarus Americanus ◽  
Diesel Oil ◽  
Chemical Components ◽  
American Lobster ◽  
Drilling Fluids ◽  
Feeding Rates ◽  
Fine Grained ◽  
Larval Stages

The lethal and sublethal effects of five used, whole drilling fluids on the larval stages of the American lobster (Homarus americanus) were assessed in laboratory experiments using a continuous-flow bioassay. Although the five tested drilling fluids varied markedly in their toxicity, some were highly toxic, with LC50 values as low as 74 mg/L. Sublethal exposures to drilling fluids at concentrations as low as 10–50 mg/L resulted in reduced respiration rates, reduced O:N ratios, and increased protein:lipid ratios, demonstrating a change in energetics of the larval lobsters. Growth and development of the larvae were seriously impaired by exposure to three of the five drilling fluids at concentrations of 50 and 100 mg/L. The feeding rates were also significantly reduced after a 24-h exposure to 50 mg/L drilling fluid. Exposure of larvae to barite (a major component of drilling fluids) and to a field-collected, fine-grained sediment did not result in deleterious effects. We suggest that the chemical components and not the physical properties of the drilling fluids are primarily responsible for detrimental effects. From results of the chemical analyses of the tested drilling fluids, we consider that the adverse effects of these drilling fluids cannot be attributed to any one group of chemicals. For example, diesel oil, a known toxicant, was present in the more toxic drilling fluids; however, there was no direct correlation between the toxicity of a drilling fluid and diesel oil concentration. Phenolic compounds, various metals, and other components probably also contributed to the toxicity of these drilling fluids.

scholarly journals Experimental evidence for concentration-dependence and intra-specific variation of movement behaviour in American lobster (Homarus americanus) larvae

2016 ◽  
Author(s):  
Eric J Pedersen ◽  
Ryan R.E. Stanley ◽  
Paul V.R. Snelgrove ◽  
Frederic Guichard
Keyword(s):  
Vertical Distribution ◽  
Substantial Reduction ◽  
Homarus Americanus ◽  
American Lobster ◽  
High Concentration ◽  
Larval Stages ◽  
Larval Behaviour ◽  
Low Concentrations ◽  
Environmental Responses ◽  
Newly Hatched Larvae

Predicting dispersal paths of marine larvae with long pelagic durations, such as American lobster (Homarus americanus), requires understanding the cues to which larvae respond, and how that response reflects changes in larval behaviour. If larvae respond to conspecific presence by varying their movement, this behaviour can bias laboratory estimates of environmental responses. We tested whether larvae actively decreased their local intraspecific density by measuring how the vertical distribution of larvae changed under high versus low concentrations of conspecifics. We observed weak increases in vertical dispersion at higher concentrations in both newly-hatched larvae and in post-larvae, but not in intermediate larval stages. Further, we found that larvae from different mothers consistently differed in vertical distribution, which may indicate maternal effects on dispersal behavior. We also tested for differences in horizontal swimming behaviour in high and low concentrations, by fitting a novel random walk model that allowed us to model both larval interactions and persistent turning behaviours. We showed substantial reduction in diffusive behaviour under high concentration conditions resulting from more frequent turns by each larva, but no evidence for consistent avoidance of conspecifics. Our study is the first to demonstrate concentration-dependent behaviours in lobster larvae.

The catchability of large American lobsters (Homarus americanus) from diving and trapping studies off Grand Manan Island, Canadian Maritimes

2006 ◽  
Vol 63 (9) ◽  
pp. 1925-1933 ◽  
Author(s):  
M J Tremblay ◽  
S J Smith ◽  
D A Robichaud ◽  
P Lawton
Keyword(s):  
Generalized Linear Models ◽  
Carapace Length ◽  
Linear Models ◽  
Size Range ◽  
Late Summer ◽  
Homarus Americanus ◽  
Agonistic Interactions ◽  
Size Groups ◽  
Early Fall ◽  
Catch Rates

Catchability (q) in traps was estimated for American lobsters (Homarus americanus) in Flagg Cove, off Grand Manan Island (New Brunswick, Canada), where large females (>100 mm carapace length (CL)) aggregate in late summer and early fall. In 2001 and 2002, diver surveys were used to estimate lobster density, and traps were then deployed to obtain catch rates. Bayesian generalized linear models were fit to the densities of different size groups (81–100, 101–130, 131–160, and >160 mm CL) of ovigerous females, non-ovigerous females, and males. Catchability was strongly affected by year. Differences in q due to sex and size for ovigerous females, non-ovigerous females, and males were apparent but were not consistent between years. Size was not an important factor for the catchability of lobsters between 81 and 160 mm CL. In comparison with lobsters of a similar size in other areas, Flagg Cove lobsters in the size range of 81–100 mm CL were less catchable. We hypothesize that this resulted from the high densities and larger sizes of lobsters in Flagg Cove, which likely lead to increased agonistic interactions and reduced entry of lobsters into traps.

Movements of Tagged American Lobsters, Homarus americanus, off Southwestern Nova Scotia

1985 ◽  
Vol 42 (2) ◽  
pp. 229-238 ◽  
Author(s):  
Alan Campbell ◽  
Aivars B. Stasko
Keyword(s):  
Nova Scotia ◽  
Continental Shelf ◽  
Carapace Length ◽  
Gulf Of Maine ◽  
Homarus Americanus ◽  
Long Distance ◽  
Mature Adults ◽  
Straight Line ◽  
Straight Line Distance ◽  
Long Distance Movement

A total of 4304 American lobsters (Homarus americanus) were tagged and released in inshore areas off southwestern Nova Scotia and on northwest Browns Bank during June–August 1975. Of the 424 lobsters recaptured within 5.4 yr of release, 385 had known recapture locations. For all release areas the average straight-line distance traveled by mature ([Formula: see text]carapace length) lobsters (15.6 km) was significantly greater than for immature (59–94 mm carapace length) lobsters (4.7 km). Most (69.3%) of the immature lobsters (N = 212) were recaptured less than 18.5 km (10 naut mi) from the release sites; for mature lobsters (N = 173) this percentage was 40.5%. Previous tagging studies off southwestern Nova Scotia revealed little evidence of long-distance movement; our study, however, shows that mature lobsters can move long distances. Many (19.7%) of the mature lobsters were recaptured more than 92.6 km (50 naut mi) from the release sites. The overall direction of travel was south, in both an east and west direction, with many lobsters moving greater than 50 km from coastal Nova Scotia and Browns Bank into the Gulf of Maine and to the slopes of the continental shelf. Thirteen lobsters moved from Browns Bank to inshore areas of southwestern Nova Scotia. The evidence of the long-distance interchange of a portion of the mature adults between southwestern Nova Scotia and the adjoining continental shelf suggests that lobsters in these areas could belong to a single stock.

The lethality of the cypermethrin formulation Excis® to larval and post-larval stages of the American lobster (Homarus americanus)

Aquaculture ◽  
2000 ◽  
Vol 182 (1-2) ◽  
pp. 37-47 ◽  
Author(s):  
L.E Burridge ◽  
K Haya ◽  
F.H Page ◽  
S.L Waddy ◽  
V Zitko ◽  
...  
Keyword(s):  
Homarus Americanus ◽  
American Lobster ◽  
Larval Stages
Sign in / Sign up

Export Citation Format

Share Document