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

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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Larval Development of the European Lobster and How Small Heterochronic Shifts Lead to a More Pronounced Metamorphosis

International Journal of Zoology ◽

10.1155/2015/345172 ◽

2015 ◽

Vol 2015 ◽

pp. 1-17 ◽

Cited By ~ 8

Author(s):

Marie A. I. N. Rötzer ◽

Joachim T. Haug

Keyword(s):

Larval Stage ◽

Stage Iv ◽

Extreme Case ◽

Homarus Americanus ◽

Stage Iii ◽

American Lobster ◽

Factors Affecting ◽

European Lobster ◽

Larval Stages ◽

Two Factors

We redescribe the larval stages of the European lobster,Homarus gammarus, based on autofluorescence composite imaging. We focus on larval stages (II) to (IV). Compared to the American lobster,Homarus americanus, differences are most apparent in stage (III). This stage appears more mature inH. gammarus; for example, the rostrum is already curved and bears spines, and the appendages are better developed and longer and more differentiated. InH. americanusstage (III) shows a stronger resemblance to stage (II). As a result of the morphology of stage (III), the “metamorphic” moult between stage (III) and stage (IV) inH. gammarusis less drastic than inH. americanus. Metamorphosis is characterised by two criteria. It involves (1) a drastic change in morphology in (2) a short amount of time. It has hence been suggested that a more pronounced metamorphosis evolves by two factors affecting these criteria, namely, (1) the evolution of specialised larval features, which increase the morphological disparity between larva and adult that makes the change of morphology more drastic, and (2) the skipping of entire stages. This means larval forms ancestrally moult over several intermediate forms into the definite adult morphology. Yet, in more derived forms the stages with intermediate morphologies are no longer expressed; highly specialized larvae moult into the adult within a single moult (in the most extreme case) hence bridging the morphologies of larvae and adult in a shorter amount of time. The example of the twoHomarusspecies demonstrates that this explanation is not the only possible one. Additionally, differences of a single larval stage (in this case larval stage (III)) can lead to a more or less metamorphic-appearing ontogenetic sequence.

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Nutritional and Bioenergetic Considerations in the Development of the American Lobster Homarus americanus

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f86-283 ◽

1986 ◽

Vol 43 (11) ◽

pp. 2311-2319 ◽

Cited By ~ 84

Author(s):

Glenn C. Sasaki ◽

Judith McDowell Capuzzo ◽

Patricia Biesiot

Keyword(s):

Elevated Temperatures ◽

Food Selection ◽

Stage Iv ◽

Homarus Americanus ◽

American Lobster ◽

Midgut Gland ◽

Juvenile Form ◽

Biochemical Processes ◽

Larval Stages ◽

Physiological And Biochemical

To better understand the early life history stages of the American lobster Homarus americanus, nutritional and bioenergetic aspects of development have been investigated. These studies focused on physiological and biochemical processes during transitional periods between extrusion of the eggs, hatching, larval development, molting, metamorphosis, and attainment of the juvenile stage. Biochemical changes during embryogenesis reflect catabolism of various substrates for energy. Exposure to different thermal regimes resulted in considerable variation in the rates of utilization of energy substrates during embryogenesis. Embryos raised at elevated temperatures had yolk remaining at the time of hatching. The first three larval stages have similar energy requirements. Lipid is of prime importance and the turnover rate for lipid can be rapid. Weight-specific metabolism increases with successive larval stages, in stage IV lobsters, the dependency on lipid as a substrate is diminished and lipid reserves serve a storage function. Metabolic rates of premolt stage IV lobsters are decreased in comparison with earlier stages. These changes in physiology correlate with changes in the developing midgut gland, specifically with the appearance of droplets of lipid in the lipid-storing cells of the midgut gland of stage IV lobsters. By stage VI, lobsters have energy storage and metabolic patterns similar to those of adults, and the midgut gland has the adult morphology. The transitions from hatching to attainment of the juvenile form are reflected in differences in physiological and biochemical processes that influence food selection and diet.

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Effect of Temperature on the Behavior of Stage IV American Lobster (Homarus americanus) Larvae

Journal of Shellfish Research ◽

10.2983/035.034.0239 ◽

2015 ◽

Vol 34 (2) ◽

pp. 545-554 ◽

Cited By ~ 7

Author(s):

Melanie Chiasson ◽

Gilles Miron ◽

Dounia Daoud ◽

Martin D. Mallet

Keyword(s):

Stage Iv ◽

Homarus Americanus ◽

Effect Of Temperature ◽

American Lobster

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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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Stock structure and connectivity of the American lobster (Homarus americanus) in the southern Gulf of St. Lawrence: Do benthic movements matter?

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/cjfas-2017-0346 ◽

2018 ◽

Vol 75 (11) ◽

pp. 2096-2108 ◽

Cited By ~ 4

Author(s):

Bryan L. Morse ◽

Brady K. Quinn ◽

Michel Comeau ◽

Rémy Rochette

Keyword(s):

Long Range ◽

Marine Environment ◽

Larval Dispersal ◽

Location Management ◽

Homarus Americanus ◽

American Lobster ◽

Stock Structure ◽

Pelagic Larvae ◽

Upstream Direction ◽

Dispersal Distances

The long-range dispersal of pelagic larvae is often assumed to be the dominant force behind connectivity in the marine environment, with little consideration given to benthic movements. We analyzed data from an American lobster (Homarus americanus) tagging study (1980–1996) in the Gulf of St. Lawrence during which 37 579 adults from 14 locations were tagged and 6296 were recaptured after 1–6 years at large. The 10th percentile greatest distance moved by tagged lobsters after 1 year at large contributed to demographic connectivity between neighbouring statistical districts, fishing ports, and (in one location) management areas. Considering the incremental dispersal of lobsters after 2 versus 1 year at large, we estimated that the 10th percentile greatest benthic dispersal distances after 1, 2, and 5 years at large represented, respectively, 7%, 14%, and 35% of larval dispersal in the “downstream” direction and 75%, 111%, and 220% of larval dispersal in the “upstream” direction (similar results obtained based on mean dispersal values). We conclude that more attention should be given to benthic movements in estimating connectivity and stock structure in American lobster.

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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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Linking rising pCO2 and temperature to the larval development and physiology of the American lobster (Homarus americanus)

ICES Journal of Marine Science ◽

10.1093/icesjms/fsw154 ◽

2016 ◽

Vol 74 (4) ◽

pp. 1210-1219 ◽

Cited By ~ 15

Author(s):

Jesica D. Waller ◽

Richard A. Wahle ◽

Halley McVeigh ◽

David M. Fields

Keyword(s):

Climate Change ◽

Larval Development ◽

Stage Iv ◽

Homarus Americanus ◽

Larval Survival ◽

Interactive Effects ◽

High Pco2 ◽

American Lobster ◽

Feeding Rates ◽

Intergovernmental Panel

Few studies have evaluated the joint effects of elevated temperature and pCO2 on marine organisms. In this study we investigated the interactive effects of Intergovernmental Panel on Climate Change predicted temperature and pCO2 for the end of the 21st century on key aspects of larval development of the American lobster, Homarus americanus, an otherwise well-studied, iconic, and commercially prominent species in the northeastern United States and Atlantic Canada. Our experiments showed that larvae (stages I–III) and postlarvae (stage IV) reared in the high temperature treatments (19 °C) experienced significantly lower survival, developed twice as fast, and had significantly higher oxygen consumption rates, than those in ambient treatments (16 °C). Larvae from the ambient temperature/high pCO2 (750 ppm) treatment had significantly longer carapace lengths, greater dry masses in stages I–III and higher C: N ratios in stage IV than larvae from all other treatments. Stage IVs raised in the high pCO2 treatment at 19 °C had significantly higher feeding rates and swimming speeds than stage IVs from the other three treatments. Together these results suggest that projected end-century warming will have greater adverse effects than increased pCO2 on larval survival, and changing pCO2 may have a complex effect on larval metabolism and behaviour. Understanding how the most vulnerable life stages of the lobster life cycle respond to climate change is essential in connecting the northward geographic shifts projected by habitat quality models, and the underlying physiological and genetic mechanisms that drive their ecology.

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

10.7287/peerj.preprints.1969v1 ◽

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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