scholarly journals Maze learning and memory in a decapod crustacean

2019 ◽  
Vol 15 (10) ◽  
pp. 20190407 ◽  
Author(s):  
Ross Davies ◽  
Mary H. Gagen ◽  
James C. Bull ◽  
Edward C. Pope
Keyword(s):  
Spatial Learning ◽  
Carcinus Maenas ◽  
Decapod Crustacean ◽  
Maze Learning ◽  
Resource Exploitation ◽  
Conditioning Period ◽  
Steady Improvement ◽  
Shore Crabs ◽  
Important Trait ◽  
Initial Description

Spatial learning is an ecologically important trait well studied in vertebrates and a few invertebrates yet poorly understood in crustaceans. We investigated the ability of European shore crabs, Carcinus maenas , to learn a complex maze over four consecutive weeks using food as a motivator. Crabs showed steady improvement during this conditioning period in both the time taken to find the food and in the number of wrong turns taken. Crabs also clearly remembered the maze as when returned two weeks later but without any food, they all returned to the end of the maze in under 8 min. Crabs that had not been conditioned to the maze (naive animals) took far longer to reach the end, and many (42%) did not venture to the end of the maze at all during the 1 h study period. This study provides an initial description of spatial learning in a benthic decapod; a better appreciation of this adaptive trait in these animals will develop our understanding of resource exploitation by benthic crustaceans and their ecological roles.

scholarly journals Influence of temperature on intraspecific, unbalanced dyadic contests between crabs

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e7845
Author(s):  
Allan T. Souza ◽  
Felipe O. Ribas ◽  
João F. Moura ◽  
Claudia Moreira ◽  
Joana Campos ◽  
...  
Keyword(s):  
Carapace Width ◽  
Carcinus Maenas ◽  
Individual Characteristics ◽  
The Body ◽  
Shore Crab ◽  
Temperature Conditions ◽  
Red Color ◽  
Shore Crabs ◽  
Influence Of Temperature On ◽  
Globally Distributed

Intraspecific agonistic interactions are widespread across the animal kingdom, with many individual morphological and physiological characteristics playing important roles in the fate of disputes. Additionally, changes to environmental conditions can influence the outcomes of animal contests. The shore crab (Carcinus maenas) is a globally distributed species, present in numerous coastal and estuarine temperate systems around the world. Although shore crabs are highly tolerant to changes in temperature, this parameter has important physiological effects on the species’ ecology, while its effects on behavior are not fully understood. Our study aims to investigate how different individual characteristics (such as sex, color morphotype, carapace and chela morphology) and temperature conditions affect the dyadic interactions between shore crabs when disputing food resources. In general, the differences in carapace width between opponents, their sexes, color morphotypes and the temperature conditions interacted and were important predictors of the contest fate. We found that the body size and color morphotype of C. maenas determined the fate of dyadic disputes. However, the higher temperatures disrupted the well-established dominance of the larger red color morphotype individuals. Overall, the agonistic contest results suggest higher plasticity than previously acknowledged.

Bilateral peripheral vestibular lesions produce long-term changes in spatial learning in the rat

2003 ◽  
Vol 13 (1) ◽  
pp. 9-16
Author(s):  
Noah A. Russell ◽  
Arata Horii ◽  
Paul F. Smith ◽  
Cynthia L. Darlington ◽  
David K. Bilkey
Keyword(s):  
Spatial Learning ◽  
Memory Task ◽  
Reference Memory ◽  
Learning Task ◽  
Maze Learning ◽  
Vestibular Information ◽  
Spatial Reference Memory ◽  
Long Term Changes ◽  
Control Lesion

In order to investigate whether bilateral peripheral vestibular lesions cause long-term impairment of spatial learning, rats were tested in a reference memory radial arm maze learning task at least 5 weeks following a bilateral labyrinthectomy (BL) or sham control lesion. All control rats reached criterion (i.e., 1 error or less, averaged across 7 trials for 3 consecutive days of training) but only 4 of the 8 BL rats had reached criterion by day 21 of the training sessions. The control rats reached criterion more quickly than the lesioned rats (Control, 7.0 ± 0.63 days, Lesioned, 15.8 ± 1.4 days, t 10 = 5.84, p < 0.0001). This difference resulted from the greater number of errors made by the BL animals. However, the latency to respond was comparable as a result of the increased locomotor activity of the BL group (i.e., ’hyperkinesis), and the overall rate of acquisition of the task, as indicated by analysis of the exponential decrease in errors over the entire training period, was not significantly different between the 2 groups. The results of this study demonstrate that BL in rats produces long-term changes in performance in a spatial reference memory task, which are not simply due to the inability to move but may relate to the way that the brain uses vestibular information to create spatial representations and determines behavioural strategies on the basis of these representations.

scholarly journals Mycosis Is a Disease State Encountered Rarely in Shore Crabs, Carcinus maenas

Pathogens ◽  
2020 ◽  
Vol 9 (6) ◽  
pp. 462
Author(s):  
Charlotte E. Davies ◽  
Sophie H. Malkin ◽  
Jessica E. Thomas ◽  
Frederico M. Batista ◽  
Andrew F. Rowley ◽  
...  
Keyword(s):  
Immune Cell ◽  
Fungal Infections ◽  
Novel Species ◽  
Carcinus Maenas ◽  
Shore Crab ◽  
Marine Animals ◽  
Cell Reactivity ◽  
Shore Crabs ◽  
Swansea Bay ◽  
Disease Signatures

There is a paucity of knowledge regarding the diversity and impact(s) of disease-causing fungi in marine animals, especially shellfish. In efforts to address this knowledge gap for the shore crab Carcinus maenas, a year-long disease screen was carried out across two sites in Swansea Bay (Wales, UK) with a view to characterising putative fungal infections. Crabs were sampled between November 2017 and October 2018, and screened systematically for disease signatures using haemolymph (blood) preparations, targeted PCR and tissue histopathology. Strikingly, mycosis was confirmed in ~0.4% of total crabs tested (n = 1191) and restricted to one location only (Mumbles Pier). Clinical infections were observed in four out of four infected crabs. In these animals, the gills and hepatopancreas were congested with fungal morphotypes. In addition, some evidence indicates haemocyte (immune cell) reactivity toward the fungi. Phylogenetic placement of the partial internal transcribed spacer (ITS1) gene regions amplified from three mycotic crabs revealed the causative agent to be related to hypocrealean fungi, thereby representing a novel species.

Weapon strength and competitive success in the fights of shore crabs (Carcinus maenas)

2000 ◽  
Vol 250 (3) ◽  
pp. 397-403 ◽  
Author(s):  
L. U. Sneddon ◽  
F. A. Huntingford ◽  
A. C. Taylor ◽  
J. F. Orr
Keyword(s):  
Carcinus Maenas ◽  
Shore Crabs ◽  
Competitive Success

scholarly journals Hypoxia increases the risk of egg predation in a nest-guarding fish

2016 ◽  
Vol 3 (8) ◽  
pp. 160326 ◽  
Author(s):  
Karin H. Olsson ◽  
Charlotta Kvarnemo ◽  
Maria Norevik Andrén ◽  
Therése Larsson
Keyword(s):  
Carcinus Maenas ◽  
High Oxygen ◽  
Filial Cannibalism ◽  
Defensive Behaviour ◽  
Low Oxygen ◽  
Pomatoschistus Minutus ◽  
Oxygen Treatment ◽  
Large Nest ◽  
Shore Crabs ◽  
Egg Guarding

For fish with parental care, a nest should meet both the oxygenation needs of the eggs and help protect them against predators. While a small nest opening facilitates the latter, it impedes the former and vice versa. We investigated how the presence of potential egg predators in the form of shore crabs Carcinus maenas affects nest building, egg fanning, defensive displays and filial cannibalism of egg-guarding male sand gobies Pomatoschistus minutus under two levels of dissolved oxygen. In the high oxygen treatment, males retained their nest opening size in the presence of crabs, while males in low oxygen built large nest openings both in the absence and presence of crabs, despite the fact that crabs were more likely to successfully intrude into nests with large entrances. Males in low oxygen also fanned more. In the presence of crabs males increased their defensive displays, but while males in high oxygen reduced fanning, males in low oxygen did not. Filial cannibalism was unaffected by treatment. Sand gobies thus prioritize egg ventilation over the protection afforded by small nest openings under hypoxia and adopt defensive behaviour to avert predator attention, even though this does not fully offset the threat from the egg predators.

Carbonic anhydrase in branchial tissues of osmoregulating shore crabs,Carcinus maenas

1990 ◽  
Vol 255 (3) ◽  
pp. 251-261 ◽  
Author(s):  
K. Böttcher ◽  
D. Siebers ◽  
W. Becker
Keyword(s):  
Carbonic Anhydrase ◽  
Carcinus Maenas ◽  
Shore Crabs
Sign in / Sign up

Export Citation Format

Share Document