American Lobster Homarus Americanus Research Articles

Seabed Habitat Determines Fish and Macroinvertebrate Community Associations in a Subarctic Marine Coastal Nursery

AbstractFish exhibit habitat‐specific distributions in heterogeneous landscapes. Many sampling techniques are limited to specific seabed types and have limited utility in comparisons of fish abundance among multiple habitats. We measured the relative abundance and the composition of fish communities in four naturally occurring coastal marine seabed types (sand–pebble, cobble, bedrock, and eelgrass) and one anthropogenic habitat type (wharf) in Newman Sound, Newfoundland, Canada, by using baited video cameras. Fish and macroinvertebrate communities were significantly different among habitat types. Winter Flounder Pseudopleuronectes americanus, Atlantic Cod Gadus morhua, and Shorthorn Sculpin Myoxocephalus scorpius were significantly more abundant over sand–pebble substrate compared with bedrock and wharf sites. Cunners Tautogolabrus adspersus and Greenland Cod Gadus macrocephalus ogac were most abundant at wharf sites. Atlantic rock crabs Cancer irroratus and American lobsters Homarus americanus avoided sand–pebble seabeds, and American lobsters were almost exclusive to bedrock sites. Cunners, Winter Flounder, and Atlantic Cod were more abundant in summer, whereas Greenland Cod and Atlantic rock crabs were more abundant during autumn months. In paired comparisons of eelgrass habitats, the community sampled by two methods was different. Relative abundance estimates from baited video cameras matched beach seine estimates for abundant predatory species (e.g., Cunner, Greenland Cod, and Atlantic rock crab), but other species, including age‐0 Greenland Cod, Shorthorn Sculpin, and White Hake Urophycis tenuis, were better represented in beach seine samples. We demonstrated substrate preferences by common coastal marine fish and crab species, which have proven difficult to enumerate via active sampling techniques in the past. Our findings will facilitate comparative studies for these species among habitat components. For species that are well sampled by using baited video cameras, this technique will advance our ability to plan for their management in the nearshore.

Effect of body size on response to emersion and molt increment of post-ovigerous female American lobsters Homarus americanus (H. Milne Edwards, 1837) (Decapoda: Nephropidae) from southern and northern Gulf of St. Lawrence, Canada

Effect of body size on response to emersion and molt increment of post-ovigerous female American lobsters Homarus americanus (H. Milne Edwards, 1837) (Decapoda: Nephropidae) from southern and northern Gulf of St. Lawrence, Canada

Effects of Prior Experience on Shelter-Seeking Behavior of Juvenile American Lobsters.

Shelter-seeking behaviors are vital for survival for a range of juvenile benthic organisms. These behaviors may be innate or they may be affected by prior experience. After hatching, American lobsters Homarus americanus likely first come into contact with shelter during the late postlarval (decapodid) stage, known as stage IV. After the subsequent molt to the first juvenile stage (stage V), they are entirely benthic and are thought to be highly cryptic. We hypothesized that postlarval (stage IV) experience with shelter would carry over into the first juvenile stage (stage V) and reduce the time needed for juveniles to locate and enter shelters (sheltering). We found some evidence of a carryover effect, but not the one we predicted: stage V juveniles with postlarval shelter experience took significantly longer to initiate sheltering. We also hypothesized that stage V juveniles would demonstrate learning by relocating shelters more quickly with immediate prior experience. Our findings were mixed. In a maze, juveniles with immediate prior experience were faster to regain visual contact with shelter, suggesting that they had learned the location of the shelter. In contrast, there was no significant effect of immediate prior experience on time to initiate sheltering in an open arena, or in the maze after juveniles had regained visual contact. We conclude that very young (stage V) juvenile lobsters modify their shelter-seeking behavior based on prior experiences across several timescales. Ecologically relevant variation in habitat exposure among postlarval and early juvenile lobsters may influence successful recruitment in this culturally and commercially important fishery species.

Fine-scale transition to lower bacterial diversity and altered community composition precedes shell disease in laboratory-reared juvenile American lobster

The American lobster Homarus americanus supports a valuable commercial fishery in the Northeastern USA and Maritime Canada; however, stocks in the southern portion of the lobster's range have shown declines, in part due to the emergence of shell disease. Epizootic shell disease is a bacterially induced cuticular erosion that renders even mildly affected lobsters unmarketable because of their appearance, and in more severe cases can cause mortality. Despite the importance of this disease, the associated bacterial communities have not yet been fully characterized. We sampled 2 yr old, laboratory-reared lobsters that displayed signs of shell disease at the site of disease as well as at 0.5, 1, and 1.5 cm away from the site of disease to determine how the bacterial community changed over this fine spatial scale. Illumina sequencing of the 16S rRNA gene revealed a distinct bacterial community at the site of disease, with significant reductions in bacterial diversity and richness compared to more distant sampling locations. The bacterial community composition 0.5 cm from the site of disease was also altered, and there was an observable decrease in bacterial diversity and richness, even though there were no signs of disease at that location. Given the distinctiveness of the bacterial community at the site of disease and 0.5 cm from the site of disease, we refer to these communities as affected and transitionary, and suggest that these bacteria, including the previously proposed causative agent, Aquimarina 'homaria', are important for the initiation and progression of this laboratory model of shell disease.

Evidence of mating by sexually immature female American lobsters Homarus americanus (H. Milne Edwards, 1837) (Decapoda: Nephropidae)

Evidence of mating by sexually immature female American lobsters Homarus americanus (H. Milne Edwards, 1837) (Decapoda: Nephropidae)

Growth of juvenile American lobster Homarus americanus in a changing environment

Growth of juvenile American lobster Homarus americanus in a changing environment

Biogeographic, ontogenetic, and environmental variability in larval behaviour of American lobster Homarus americanus

Biogeographic, ontogenetic, and environmental variability in larval behaviour of American lobster Homarus americanus

Movements and activity levels of juvenile American lobsters Homarus americanus in nature quantified using ultrasonic telemetry

Movements and activity levels of juvenile American lobsters Homarus americanus in nature quantified using ultrasonic telemetry

Short-run Economic Benefits from Water Quality Improvements: an Application to the American Lobster (Homarus Americanus) Fishery of Long Island Sound

This article proposes a quantitative investigation of the claim that improving water quality does not yield rents in commercial fisheries that are inefficiently managed. Specifically, a combined model of the resource dynamics and fishing effort is used to investigate the effects of policy scenarios on water quality improvements on the American lobster fishery in Long Island Sound. Results indicate that short-run positive rents can be extracted from the lobster fishery even when inefficiently managed, but they dissipate in the long-run as suggested by the economic literature.

The effect of temperature on foraging activity and digestion in the American lobster Homarus americanus (Milne Edwards, 1837) (Decapoda: Nephropsidae) feeding on blue mussels Mytilus edulis (Linnaeus, 1758)

The foraging activity and digestive processes of the American lobster Homarus americanus , feeding on blue mussels, Mytilus edulis were investigated over a temperature range of 5-15°C. Lobsters ate more food with increasing temperature, consuming maximal levels of approximately 5% of their body mass of mussel flesh in one sitting in 15°C water. When foraging behaviour was observed over 7 days, lobsters were more active outside of their shelter at 10 and 15°C and consumed more mussels at these two temperatures. Although lobsters were more active during the hours of darkness, they still exited shelters and fed during the light period if food was available. The lobsters consumed at least one mussel every 15.8, 7.8, and 4.7 h in temperatures of 5, 10, and 15°C, respectively. The passage of a mussel meal through the digestive system of lobsters was considerably slower compared with other decapod crustaceans. Transit rate decreased as the temperature was increased, with clearance times of 252, 133 and 69 h in temperatures of 5, 10, and 15°C. Although the time between feeding bouts decreased with increasing temperature, at the time of next feeding the amount of food that had been cleared from the foregut was the same in each temperature (approximately 20%), suggesting that this proportion of stomach emptying could be the cue for next feeding. Recent work has suggested that lobster numbers increase in the presence of mussel aquaculture operations. This work gives further insight into the feeding behaviour and activity around mussel farms, and suggests that lobsters could be an effective means of removing moribund mussels that could be lost during the harvesting process.

Behavioral Thermoregulation and Trade-Offs in Juvenile Lobster Homarus americanus.

Water temperature influences the behavior and distribution patterns of both larval and adult American lobster Homarus americanus. However, very little is known about the responses of juvenile lobsters. The juvenile life stage is a critical period; high levels of mortality, combined with specific behavioral responses, can disconnect larval settlement from patterns of abundance of adults. We assessed behavioral thermoregulation in juvenile lobsters, and determined how thermal preferences can be altered by the presence of shelter and food. Juvenile lobsters avoided temperatures higher than 20 °C and lower than 8 °C, and had a mean temperature preference of 16.2 ± 1 °C. This preference was unaffected by prior acclimation, origin (laboratory-raised or wild), or size. When the animals were subjected to a temperature change (5-20 °C), activity rates peaked at 15 °C, and remained stable thereafter. Activity rates did not change when a shelter was added. The addition of food resulted in an increase in activity associated with food handling. When juvenile lobsters were offered a choice between temperature, shelter, and food, they always chose the environment with a shelter, even when it was in a thermally unfavorable temperature. Juveniles also spent more time in a thermally unfavorable environment when food was present; however, acquisition of a shelter was prioritized over food. Although juveniles had a similar thermal preference to adults, they are more vulnerable to predation; the innate shelter-seeking behavior of juveniles overrode their thermal preference. While temperature is an important environmental factor affecting the physiology, distribution, and growth of aquatic ectotherms, our findings suggest that trade-off behaviors occur in order to maintain optimal fitness and survival of the individual.

Neuropeptidergic Signaling in the American Lobster Homarus americanus: New Insights from High-Throughput Nucleotide Sequencing.

Peptides are the largest and most diverse class of molecules used for neurochemical communication, playing key roles in the control of essentially all aspects of physiology and behavior. The American lobster, Homarus americanus, is a crustacean of commercial and biomedical importance; lobster growth and reproduction are under neuropeptidergic control, and portions of the lobster nervous system serve as models for understanding the general principles underlying rhythmic motor behavior (including peptidergic neuromodulation). While a number of neuropeptides have been identified from H. americanus, and the effects of some have been investigated at the cellular/systems levels, little is currently known about the molecular components of neuropeptidergic signaling in the lobster. Here, a H. americanus neural transcriptome was generated and mined for sequences encoding putative peptide precursors and receptors; 35 precursor- and 41 receptor-encoding transcripts were identified. We predicted 194 distinct neuropeptides from the deduced precursor proteins, including members of the adipokinetic hormone-corazonin-like peptide, allatostatin A, allatostatin C, bursicon, CCHamide, corazonin, crustacean cardioactive peptide, crustacean hyperglycemic hormone (CHH), CHH precursor-related peptide, diuretic hormone 31, diuretic hormone 44, eclosion hormone, FLRFamide, GSEFLamide, insulin-like peptide, intocin, leucokinin, myosuppressin, neuroparsin, neuropeptide F, orcokinin, pigment dispersing hormone, proctolin, pyrokinin, SIFamide, sulfakinin and tachykinin-related peptide families. While some of the predicted peptides are known H. americanus isoforms, most are novel identifications, more than doubling the extant lobster neuropeptidome. The deduced receptor proteins are the first descriptions of H. americanus neuropeptide receptors, and include ones for most of the peptide groups mentioned earlier, as well as those for ecdysis-triggering hormone, red pigment concentrating hormone and short neuropeptide F. Multiple receptors were identified for most peptide families. These data represent the most complete description of the molecular underpinnings of peptidergic signaling in H. americanus, and will serve as a foundation for future gene-based studies of neuropeptidergic control in the lobster.

Evaluation of Effectiveness of Fixed‐Station Sampling for Monitoring American Lobster Settlement

AbstractThe American lobster Homarus americanus supports one of the most valuable fisheries in the USA. One of the important monitoring programs is for benthically settled lobsters, which closely relates to recruitment. The lobster settlement sampling program follows a fixed‐station design. However, the performance of this design has not been evaluated, and we are unclear if the design can capture the temporal dynamics of settlers, in particular in response to changes in spatial distribution of lobster in the last 2 decades. In this study, we compared the fixed‐station design with a random sampling design for the mid‐coast region of the Gulf of Maine. We developed a generalized additive model (GAM) to quantify the relationship between habitat variables and density of early benthic phase and older juvenile lobsters by using the data from inshore trawl surveys from 1989 to 2012. The GAM model was then used to simulate putative true populations using the habitat variables. The two different sampling designs were applied to sample the simulated true populations. The fixed‐station sampling design tended to underestimate the true density but could capture the temporal trends in settler density. A persistence index analysis suggests that the fixed‐station design could identify interannual change of the lobster settler density. This study suggests that fixed‐station sampling design is effective in monitoring temporal changes in settler density but could not be used for the estimation of absolute density of settlers.Received December 16, 2014; accepted July 9, 2015

A Field‐Based Nursery for Headstarting Lobsters to Improve Postrelease Survival for Potential Stock Enhancement in Long Island Sound, Connecticut

AbstractEarly benthic stage American lobsters Homarus americanus were held in a pilot nursery system in Long Island Sound (LIS), Connecticut, to test field grow out as a step toward potential stock enhancement. A larger size upon release may increase the probability of survival. Lobsters were placed individually in perforated plastic mesh cylindrical “habitats,” and each habitat was housed in an outer protective sleeve with a larger mesh size. During June 2013, 24 lobsters were transferred to each of three wire mesh cages and deployed southwest of Charles Island in Milford, Connecticut (N = 3). The only source of nutrition was naturally occurring organisms. Cages were retrieved monthly, and lobsters were photographed to measure changes in carapace length (CL). After 11 months in the field, lobsters increased 92% in mean size from 6.0‐ to 11.6‐mm CL, with 70.8% overall survival. Headstarting of early benthic stage lobsters shows promise as a tool for possible future stock enhancement in LIS.

Seasonal movements of American lobsters in southern Gulf of Maine coastal waters: patterns, environmental triggers, and implications for larval release

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 524:197-211 (2015) - DOI: https://doi.org/10.3354/meps11192 Seasonal movements of American lobsters in southern Gulf of Maine coastal waters: patterns, environmental triggers, and implications for larval release Jason S. Goldstein*, Winsor H. Watson III University of New Hampshire, Department of Biological Sciences, 46 College Road, Durham, New Hampshire 03824, USA *Corresponding author: jsgoldstein2@gmail.com ABSTRACT: American lobsters Homarus americanus are known to move offshore during the fall-to-winter transition and inshore, into shallower, warmer water in the spring and summer. To determine whether all types of lobsters in New Hampshire coastal waters exhibit this movement pattern, we fitted 45 lobsters (ovigerous and non-ovigerous females, and males) with ultrasonic transmitters and tracked their movements over 3 successive seasons from 2006 to 2009. The major goals of this study were to determine (1) if ovigerous females express different seasonal movement patterns than males or non-ovigerous females; (2) what environmental cues might trigger offshore movements in the fall; and (3) the location of ovigerous females when their eggs hatch in the spring-summer. Most lobsters (82%) moved >0.5 km, whereas the rest remained close to their original release location. Of the lobsters that moved, 51% moved <5 km, 19% moved 5-10 km, and 30% moved >10 km. There were no significant differences in the seasonal movements of ovigerous females compared with non-ovigerous females, but females as a group moved significantly farther than males. The ovigerous lobsters that moved offshore tended to remain there until the time when their eggs most likely hatched. In conclusion, the seasonal movements of ovigerous lobsters in coastal waters significantly influence the location and timing of larval hatch and, ultimately, settlement. KEY WORDS: Acoustic telemetry · Seasonal movements · Ovigerous lobsters · Larval dispersal · Homarus americanus Full text in pdf format PreviousNextCite this article as: Goldstein JS, Watson WH III (2015) Seasonal movements of American lobsters in southern Gulf of Maine coastal waters: patterns, environmental triggers, and implications for larval release. Mar Ecol Prog Ser 524:197-211. https://doi.org/10.3354/meps11192 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 524. Online publication date: March 30, 2015 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2015 Inter-Research.

Bisphenol A and the related alkylphenol contaminants in crustaceans and their potential bioeffects

Bisphenol A is widely used in plastic and other industrial consumer products. Release of bisphenol A and its analogues into the aquatic environment during manufacture, use and disposal has been a great scientific and public concern due to their toxicity and endocrine disrupting effects on aquatic wildlife and even human beings. More recent studies have shown that these alkylphenols may affect the molting processes and survival of crustacean species such as American lobster, crab and shrimp. In this study, we have developed gas chromatography with flame ionization detection (GC-FID) and gas chromatography- mass spectrometric (GC-MS) methods for the determination of bisphenol A and its analogues in shrimp Macrobrachium rosenbergii, blue crab Callinectes sapidus and American lobster Homarus americanus samples. Bisphenol A, 2,4-bis-(dimethylbenzyl)phenol and 4-cumylphenol were found in shrimp in the concentration ranges of 0.67-5.51, 0.36-1.61, and < LOD (the limit of detection)-1.96 ng/g (wet weight), and in crab of 0.10-0.44, 0.13-0.62, and 0.26-0.58 ng/g (wet weight), respectively. In lobster tissue samples, bisphenol A, 2-t-butyl-4-(dimethylbenzyl)phenol, 2,6-bis-(t-butyl)-4-(dimethylbenzyl)phenol, 2,4-bis- (dimethybenzyl)phenol, 2,4-bis-(dimethylbenzyl)-6-t-butylphenol and 4-cumylphenol were determined at the concentration ranges of 4.48-7.01, 1.23-2.63, 2.71-9.10, 0.35-0.91, 0.64-3.25, and 0.44-1.00 ng/g (wet weight), respectively. At these concentration levels, BPA and its analogs may interfere the reproduction and development of crustaceans, such as larval survival, molting, metamorphosis and shell hardening.

Influence of mussel aquaculture on the distribution of vagile benthic macrofauna in îles de la Madeleine, eastern Canada

AEI Aquaculture Environment Interactions Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections AEI 6:175-183 (2015) - DOI: https://doi.org/10.3354/aei00123 Influence of mussel aquaculture on the distribution of vagile benthic macrofauna in îles de la Madeleine, eastern Canada Annick Drouin1,2,*, Philippe Archambault2, Brianna Clynick1,2, Karine Richer1, Christopher W. McKindsey1,2 1Institut Maurice Lamontagne, Fisheries and Oceans Canada, 850 route de la mer, Mont-Joli, Québec G5H 3Z4, Canada 2Institut des sciences de la mer, Université du Québec à Rimouski, 310 allée des Ursulines, Rimouski, Québec G5L 3A1, Canada *Corresponding author: annick.drouin@gmail.com ABSTRACT: We examined spatial variation in the abundance of 4 benthic vagile species in a lagoon with blue mussel Mytilus edulis aquaculture (inside vs. outside of the mussel lease; among areas with 1 yr old, 2 yr old and harvested mussels; and with distance from mussel lines). American lobster Homarus americanus, Atlantic rock crab Cancer irroratus, common starfish Asterias rubens and winter flounder Pseudopleuronectes americanus were all at least 3 times more abundant in the farm area with 2 yr old mussels, where mussel fall-off is more frequent, than in areas outside of the farm or other areas within the farm. A strong association of lobsters with mussel line structures was observed, where most individuals were observed directly under the mussel lines, close to anchor blocks, in the areas with 1 yr old, 2 yr old and harvested mussels (58, 42 and 57%, respectively). Mussel farms influence the distribution of benthic macrofauna at a number of spatial and temporal scales, and this may be due to a number of mechanisms, depending on the species. An in situ experiment was done to separate the influence of anchor blocks and mussel fall-off on the distribution of lobsters, crabs, starfish and flounders. Results of the manipulative experiment highlighted the importance of shelter structures over a short-term period for lobsters, but not for the other 3 species. Conclusions from the observations and the manipulative experiment suggest that lobster distribution is a function of both physical structure and feeding opportunities, whereas the distribution of the other species was mainly due to trophic effects. KEY WORDS: Mytilus edulis · Homarus americanus · Cancer irroratus · Asterias rubens · Pseudopleuronectes americanus · Spatial variation · Environmental impact Full text in pdf format PreviousNextCite this article as: Drouin A, Archambault P, Clynick B, Richer K, McKindsey CW (2015) Influence of mussel aquaculture on the distribution of vagile benthic macrofauna in îles de la Madeleine, eastern Canada. Aquacult Environ Interact 6:175-183. https://doi.org/10.3354/aei00123 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in AEI Vol. 6, No. 2. Online publication date: February 04, 2015 Print ISSN: 1869-215X; Online ISSN: 1869-7534 Copyright © 2015 Inter-Research.

Selected nutrient profiles in first larvae and postlarvae of American lobster (Homarus americanus)

Initiatives to enhance natural stock of lobster imply the production of high-quality postlarvae. The aim of this study was to evaluate the physiological condition of postlarvae produced under hatchery conditions by comparing the nutrient profiles of larvae stage I and postlarvae stage IV of American lobster (Homarus americanus) fed frozen adult Artemia with a mixture of dry commercial products. Body sterols, acetone mobile polar lipids and phospholipids levels were lower in stage IV than in stage I, while cholesterol was nearly 400 % higher in the former. The C20 mono-unsaturated acids and C22 n-3 decreased between stage I and IV in both neutral and polar lipids, while linoleic (18:2n-6 cis) and linolenic (18:3n-3) acids increased concomitantly. The levels of docosahexaenoic acid (DHA) in the polar fraction were twice lower in postlarvae compared to stage I larvae and almost completely depleted in the neutral fraction while eicosapentaenoic acid levels were reduced by nearly 30 % in the polar lipids and by over 70 % in the neutral lipids. Results suggested possible dietary phospholipids and DHA deficiencies that lead to the low levels observed in the postlarvae stage IV.

Size-at-age and body condition of juvenile American lobsters (Homarus americanus) living on cobble and mud in a mixed-bottom embayment in the Bay of Fundy

American lobsters, Homarus americanus, prefer structurally complex cobble bottom for settlement and early development, but this habitat is sparse and some juveniles are likely forced to exploit other habitats, such as mud bottom. Size-at-age and body condition of juvenile lobsters may vary between cobble and mud habitats, due to differences in food and shelter the habitats provide. In this study, we used cobble-filled collectors deployed on mud and cobble bottom to capture juvenile lobsters occupying cobble and mud seafloor in a mixed-bottom embayment in the southwestern Bay of Fundy, Canada. We compared their size-at-age using a recently developed age-determination technique, and their body condition using mass–length relationship, RNA/DNA ratio and protein content. Individuals 3 and 4 years of age inhabiting mud bottom had greater carapace length than same-age conspecifics on cobble, which could be due to greater growth of juveniles in the less preferred mud habitat. We also found that for a similar carapace length lobsters on mud had slightly lower body mass than those on cobble. RNA/DNA ratio and protein content did not differ between juveniles sampled from the two habitats. Our results suggest that mud bottom represents a more important habitat for young lobsters than is currently appreciated. We hypothesize that mud bottom has become a more important juvenile habitat in recent years due to high lobster abundance, which may be forcing some juveniles to move from preferred but saturated cobble patches to other habitats, such as mud.

The complete mitochondrial genome of the Japanese fan lobster Ibacus ciliatus (Crustacea, Achelata, Scyllaridae)

Slipper lobsters are a unique group of decapod crustaceans; they have cylindrical or flattened bodies and belong to the family Scyllaridae. The genus Ibacus (Leach, 1815) (Achelata, Scyllaridae, Ibacinae) consists of eight recognized species to date, all of which occur in the Indo-West Pacific Ocean and are commercially important seafood species. The complete mitochondrial genome of the Japanese fan lobster Ibacus ciliatus (Von Siebold, 1824) is 15,696 bp in size and consists of 13 protein-coding genes, 22 transfer RNAs, 2 ribosomal RNAs, and a control region of 783 bp. The base composition of I. ciliatus is 35.8% A, 34.7% T, 19.0% C, and 10.5% G, with an overall AT content of 70.5%. The mitogenome of I. ciliatus was found to have gene arrangement and transcriptional polarity identical to that of the American lobster Homarus americanus, showing the pancrustacean ground pattern. Here, we present the complete mitogenome sequence of I. ciliatus; it is the first mitogenome information from the subfamily Ibacinae, and represents the second for the family Scyllaridae.