Experimental evidence for concentration-dependence and intraspecific variation of movement behaviour in American lobster (Homarus americanus) 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.

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

10.7287/peerj.preprints.1969 ◽

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.

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Detection of Dissolved Substances by the American Lobster (Homarus americanus) and Olfactory Attraction between Lobsters

Journal of the Fisheries Research Board of Canada ◽

10.1139/f70-161 ◽

1970 ◽

Vol 27 (8) ◽

pp. 1371-1378 ◽

Cited By ~ 79

Author(s):

D. W. McLeese

Keyword(s):

Amino Acids ◽

Sex Attractant ◽

Homarus Americanus ◽

Mature Female ◽

American Lobster ◽

High Concentration ◽

Beta Alanine ◽

Sex Attractant Pheromone ◽

Low Concentrations ◽

Attractant Pheromone

Of 17 amino acids and other organic compounds tested at high concentration, 13 elicited feeding and walking responses in lobsters significantly greater than those elicited by seawater controls, but only 7 of 29 were stimulatory at low concentrations (alanine, beta alanine, glutamic acid, proline, succinic and malic acids, and tyrosine). Fourteen of 15 mixtures of 2–9 amino acids were stimulatory. There may have been potentiation in mixtures with cysteine HCl, lysine, glycine HCl, and methionine and antagonism in some with alanine and arginine. Freshly prepared seawater extracts of cod, shrimp, and lobster muscle were more stimulatory than any of the compounds or mixtures.Male lobsters responded more frequently to water from a tank with a recently moulted mature female lobster than to water from a tank with a nonmoulted mature female or a moulted or a nonmoulted male. It is possible that moulted females release a sex attractant (pheromone).

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

Aquaculture ◽

10.1016/0044-8486(74)90081-7 ◽

1974 ◽

Vol 3 (3) ◽

pp. 311-314 ◽

Cited By ~ 10

Author(s):

Steven A. Serfling ◽

Jon C. Van Olst ◽

Richard F. Ford

Keyword(s):

Homarus Americanus ◽

American Lobster ◽

Larval Stages

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THE EFFECTS OF CRUDE OIL ON LARVAE OF LOBSTER HOMARUS AMERICANUS

International Oil Spill Conference Proceedings ◽

10.7901/2169-3358-1977-1-569 ◽

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.

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

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f86-266 ◽

1986 ◽

Vol 43 (11) ◽

pp. 2177-2183 ◽

Cited By ~ 22

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.

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Aspects of the Biology of Pseudocarcinonemertes homari and Its Association with the American Lobster, Homarus americanus

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f85-044 ◽

1985 ◽

Vol 42 (2) ◽

pp. 351-356 ◽

Cited By ~ 30

Author(s):

D. E. Aiken ◽

S. L. Waddy ◽

L S. Uhazy

Keyword(s):

Larval Development ◽

Homarus Americanus ◽

Egg Mass ◽

American Lobster ◽

Free Swimming ◽

European Lobster ◽

Newly Hatched Larvae

Pseudocarcinonemertes homari can reproduce on and destroy the egg mass of both the American (Homarus americanus) and the European lobster (H. gammarus) but does not appear to be a problem for brachyuran species. The eggs of P. homari are subspherical, average 251 × 260 μm, and are contained in individual compartments in a membranous brood sac that is attached to the lobster abdomen or egg mass. An average of 39 eggs occur in a brood sac. Newly hatched larvae are ciliated, lack anterior and posterior tufts, cirri or flagella, and are retained in the brood sac. Larval development is direct, and there is no free-swimming stage. After the larvae break out of the brood sac they join the adults and juveniles on the lobster egg mass. Many lobsters gradually remove infested eggs, but on those that do not, the nemertean population can increase to more than 14 000 individuals. After the lobster eggs are destroyed, the nemerteans disperse. Some form mucoid aggregations at protected sites on the exoskeleton; others move to the branchial chamber and gills or transfer to other lobsters. Reproduction occurs almost exclusively on the lobster egg mass, but P. homari appears capable of reproducing on lobster gills if denied access to lobster eggs for extended periods.

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

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f84-163 ◽

1984 ◽

Vol 41 (9) ◽

pp. 1334-1340 ◽

Cited By ~ 5

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.

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