摘要:

A series of laboratory tests on the snapping shrimp,Alpheus heterochaelis(Say), revealed that after removal of the large chela or immobilization of its dactylus, the shrimp could not compete successfully with normal shrimp in acquiring or holding a shelter. Evidently, the action components of the dactylus play a primary role in the successful defense of a shelter. Unlike normal shrimp or shrimp with an immobilized dactylus, shrimp lacking the large chela often were allowed to encroach beneath the shelter by their like‐sexed competitors, suggesting that the structure of the chela itself and not its movements elicits aggressive behaviour by adversaries. The absence or immobilization of the chela did not seem to affect heterosexual pairings.

ISSN:0091-181X    

DOI:10.1080/10236247809378534

出版商:Taylor & Francis Group    

年代:1978

数据来源: Taylor

摘要:

Shells found around the dens ofOctopus dofleiniwere examined for indications of handling methods used by the predators. The octopus attacks gastropod and bivalve prey by drilling, breaking and pulling apart. The size of the prey does not seem to determine the method of attack and the size of the predator also did not seem to be a significant determinant although small octopuses drilled more often than expected. The method of attack appears to be dependent on the nature of the shell and likely on the previous experience of the octopus.

ISSN:0091-181X    

DOI:10.1080/10236247809378535

出版商:Taylor & Francis Group    

年代:1978

数据来源: Taylor

摘要:

CAP organs are the crustacean equivalent of insect hair plates. In the lobsterHomarus gammarusthey are located at the IM (ischium‐merus), MC (merus‐carpus) and CP (carpuspropus) joints on the distal side of the articulation. They are typically fan‐shaped and composed of numerous peg‐like sensillae. The numbers of individual sensillae in each organ increase with size of the animal.

ISSN:0091-181X    

DOI:10.1080/10236247809378536

出版商:Taylor & Francis Group    

年代:1978

数据来源: Taylor

摘要:

Observation of male‐female pairs of lobsters after 18 days of isolation in the laboratory revealed successful mating in seven of 12 pairs and intense courtship interactions in ten of 12 pairs. These data question previously reported results which suggested that mating in this species is restricted to a 24‐hour post‐molt interval.

ISSN:0091-181X    

DOI:10.1080/10236247809378537

出版商:Taylor & Francis Group    

年代:1978

数据来源: Taylor

摘要:

Mechanosensory activity was recorded extracellularly from branches of the internal pedal nerve in the femur of the horseshoe crab walking leg. The receptors appeared to be associated with the tibial flexor muscles and generally showed little spontaneous activity in the isolated leg. Sensory activity was most easily and reliably elicited by active flexor contraction against a load, and it did not require joint movement. The neurons responsible for this activity appear to be true series tension receptors. Since such cells are likely to be adequately stimulated only by tension developed in muscle fibers with which they are in series, whole muscle tension is not always directly related to the activity of a given receptor. In order to estimate the magnitude of the force at a receptor under study various indirect methods of altering the tension in and spatial relationships between the fibres of a single muscle were employed. These include active stimulation while (a) fixing the muscle at various lengths (joint angles), (b) lengthening or shortening the muscle passively over a wide range and at varying rates. The results obtained are consistent with the suggestion that the sensory cells are series tension receptors.

ISSN:0091-181X    

DOI:10.1080/10236247809378538

出版商:Taylor & Francis Group    

年代:1978

数据来源: Taylor

摘要:

The organization of peg‐like sensillae composing CAP organs is described for a number of representative decapod crustacea. In Natantian forms the sensillae are aligned in linear fashion on the distal side of the appropriate joints. One example,Pasiphaea,possesses a cluster of hair sensillae instead of pegs, possibly indicating the primitive origin of this organ system. In the Reptantia the Macrura have well‐developed groups of sensillae, arranged in broad fan‐shaped arrangements; the Anomura display rather varied plans of small sensillae, and inPorcellanaonly one group on maxilliped 3 are found. The Brachyura have no CAP organs. The significance of these findings, and their possible implication in the evolution of internal proprioceptors in the crustacea, is discussed.

ISSN:0091-181X    

DOI:10.1080/10236247809378539

出版商:Taylor & Francis Group    

年代:1978

数据来源: Taylor

摘要:

The distances of separation at which individuals of the territorial shrimpGonodactylus oerstediishowed agonistic behaviors were measured in the laboratory. Sizes of interacting animals had no effect on distances at which behavior patterns were shown. Different acts occurred at significantly different distances.

ISSN:0091-181X    

DOI:10.1080/10236247809378540

出版商:Taylor & Francis Group    

年代:1978

数据来源: Taylor

ISSN:0091-181X    

DOI:10.1080/10236247809378533

出版商:Taylor & Francis Group    

年代:1978

数据来源: Taylor