scholarly journals The humoral immune systems of the American lobster (Homarus americanus) and the European lobster (Homarus gammarus)

2017 ◽  
Vol 186 ◽  
pp. 367-371 ◽  
Author(s):  
Timothy J. Bowden
Keyword(s):  
Homarus Americanus ◽  
American Lobster ◽  
Immune Systems ◽  
European Lobster ◽  
Homarus Gammarus ◽  
Humoral Immune

scholarly journals Recorded captures of American lobster (Homarus americanus) in Swedish waters and an observation of predation on the European lobster (Homarus gammarus)

2017 ◽  
Vol 74 (10) ◽  
pp. 1503-1506 ◽  
Author(s):  
Vidar Øresland ◽  
Mats Ulmestrand ◽  
Ann-Lisbeth Agnalt ◽  
Gert Oxby
Keyword(s):  
Native Species ◽  
Homarus Americanus ◽  
American Lobster ◽  
Swedish West Coast ◽  
Marine Research ◽  
European Lobster ◽  
Homarus Gammarus ◽  
Genetic Sampling ◽  
Identification Measurements ◽  
First Time

The intentional or unintentional release of American lobsters (Homarus americanus), imported through the European seafood trade, has resulted in findings of H. americanus in European waters. A total of 36 specimens was recorded within a smaller area, halfway along the Swedish west coast, between 2008 and 2016. The lobsters were caught by both recreational and professional fishermen and delivered to the Institute of Marine Research in Lysekil, where species identification, measurements, and genetic sampling were performed. Twenty-five of these lobsters were caught inside the sill of the Gullmar Fjord, most of them close to Lysekil harbor, where escapes from an illegal holding is suspected. Six females had eggs, which in two cases were hybrids. While there is no evidence to suggest that a population has been established in the Gullmar Fjord or elsewhere in Swedish waters, serious concerns must be raised regarding the possible consequences for the native species. An American lobster has for the first time been filmed eating a killed European lobster (Homarus gammarus) in Swedish waters.

Nutritional Quality of the Edible Tissues of European Lobster Homarus gammarus and American Lobster Homarus americanus

2009 ◽  
Vol 57 (9) ◽  
pp. 3645-3652 ◽  
Author(s):  
Sara Barrento ◽  
António Marques ◽  
Bárbara Teixeira ◽  
Paulo Vaz-Pires ◽  
Maria Leonor Nunes
Keyword(s):  
Nutritional Quality ◽  
Homarus Americanus ◽  
American Lobster ◽  
European Lobster ◽  
Homarus Gammarus ◽  
Edible Tissues

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

1985 ◽  
Vol 42 (2) ◽  
pp. 351-356 ◽  
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.

The polychaete Histriobdella homari and major groups of epibionts on the European lobster, Homarus gammarus and other decapods

Crustaceana ◽  
2019 ◽  
Vol 92 (2) ◽  
pp. 189-203
Author(s):  
Vidar Øresland
Keyword(s):  
Carapace Length ◽  
Homarus Americanus ◽  
Parasitic Copepod ◽  
Analytic Method ◽  
Quantitative Biology ◽  
European Lobster ◽  
Homarus Gammarus ◽  
First Time

Abstract The quantitative biology and ecology of epibiotic communities on decapods are only vaguely known. An analytic method revealed close to 100% of metazoan epibionts among the eggs and gills of some decapods in Swedish waters. High abundances of the epibiotic polychaete Histriobdella homari were found (100% prevalence) and European lobsters, Homarus gammarus, with a carapace length of 100 mm have, as a mean, approx. 6700 H. homari among their old eggs, underlining the importance of these epibiont polychaetes as cleaners of lobster eggs (and gills). For the first time, a nematode (Pontonema sp.) was found feeding on H. homari. Gills of American lobsters, Homarus americanus, caught in Swedish waters were infested with the European parasitic copepod Nicothoe astaci (80% prevalence). This study shows that on decapods a number of epibionts (Ciliophora, Nematoda, Hydrachnidia, Copepoda, Ostracoda, Amphipoda and Kinorhyncha) can be quantified, using the method adopted here, which will enable a better understanding of epibiotic communities.

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

2015 ◽  
Vol 2015 ◽  
pp. 1-17 ◽  
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.

Investigating fecundity and egg loss using a non-invasive method during brooding in European lobster (Homarus gammarus)

2019 ◽  
Vol 76 (6) ◽  
pp. 1871-1881 ◽  
Author(s):  
Matthew T Coleman ◽  
Joanne S Porter ◽  
Michael C Bell
Keyword(s):  
Low Cost ◽  
Dry Weight ◽  
Homarus Americanus ◽  
European Lobster ◽  
Homarus Gammarus ◽  
Non Invasive ◽  
Brooding Period ◽  
Significant Difference ◽  
Invasive Method ◽  
Depth Gauge

Abstract This article examines two important components of measurement of fecundity in the European lobster Homarus gammarus: (i) comparing the traditional gravimetric dry weight fecundity method against two non-invasive depth gauge methods initially developed for Homarus americanus and (ii) utilizing the depth gauge method to determine egg loss during the brooding period and its impacts on effective fecundity estimates. No significant difference was observed between fecundity estimates derived using either the traditional or depth gauge methods. Derived fecundity estimates from the two depth gauge methods differed by −0.31% (±2.7 s.e.) for cylinder and −1.1% (±2.4 s.e.) for ellipsoid fecundity estimates compared with the traditional method. This highlights the utility of the depth gauge method for providing fast, reliable and low-cost estimates without sacrificing lobsters or their egg masses. Egg loss is estimated to be as high as 44% from initial extrusion to hatching. The application of the non-invasive methods for estimating fecundity to other fisheries and stocks is discussed along with the importance of understanding egg loss in this commercially valuable fishery.

Development, characterisation, inheritance, and cross-species utility of American lobster (Homarus americanus) microsatellite and mtDNA PCR-RFLP markers

Genome ◽  
2003 ◽  
Vol 46 (1) ◽  
pp. 59-69 ◽  
Author(s):  
Matthew W Jones ◽  
Patrick T O'Reilly ◽  
Arran A McPherson ◽  
Tara L McParland ◽  
Dawn E Armstrong ◽  
...  
Keyword(s):  
Genetic Markers ◽  
Multiple Paternity ◽  
Pcr Amplification ◽  
Homarus Americanus ◽  
Rflp Markers ◽  
American Lobster ◽  
European Lobster ◽  
Population Discrimination ◽  
Mtdna Sequence ◽  
Pcr Rflp

Effective management of exploited species demands contemporary knowledge of population structure and mating patterns. Genetic markers can prove useful in providing this knowledge. Despite its commercial importance, genetic markers for American lobster (Homarus americanus) are limited. We developed 12 tetra- and 1 trinucleotide microsatellite loci for American lobster that exhibit little stuttering after PCR amplification. Gene diversity of these loci ranged from 0.516 to 0.929. A four-locus multiplex permits rapid genotyping of progeny in parentage experiments with a paternity exclusion probability over the four loci of 97.8%. We examined the loci for conformity to Hardy-Weinberg expectations (HWE) and linkage using individuals from one location and found that four loci deviated from HWE. We also tested inheritance and pairwise linkage using 48 embryos from each of two females. With the exception of two loci that were derived from the same clone and separated by 72 bp, no evidence of linkage was found. We, for the first time, demonstrate the occurrence of multiple paternity in American lobster. We also observed an apparent occurrence of dispermic androgenesis, possibly the first documentation of such an event within a species. Ten of the loci amplified in European lobster (Homarus gammarus), although two were monomorphic and one deviated significantly from HWE. We quantified mitochondrial DNA (mtDNA) sequence variation through the use of PCR amplification of two DNA fragments, followed by digestion with restriction enzymes; eight haplotypes were detected. One of the two fragments amplified in European lobster. Both sets of markers should prove useful for population discrimination purposes, and the microsatellites, in particular the four-locus multiplex, should prove highly amenable to rapidly addressing questions about mating patterns.Key Words: low-stutter microsatellites, mtDNA PCR–RFLP, multiple paternity, dispermic androgenesis, American lobster.

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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