Pugettia Research Articles

Effects of abrasion and Na+ on dactyl-mediated chemoreception in mature kelp crabs, Pugettia producta (Randall).

Extracellular recordings from the mixed sensory nerves innervating the abraded dactylopodites of the kelp crab, Pugettia producta (Randall), indicate that at least some chemoreceptors and mechanoreceptors remain functional. The chemoreceptors of the abraded dactyls are sensitive to both the concentration and chemical nature of the stimulants. The responses of the chemoreceptors, but not of the mechanoreceptors, are reduced when choline is substituted for sodium in the stimulant solutions. Only chemoreception is blocked by the topical application of tetrodotoxin (TTX) to the dactyls; partial reversal of the blockage occurs with time. The differential blockage of receptor activity by low Na+ and TTX is consistent with the idea that spike initiation occurs more distally in the dendrites of the chemosensory neurons than in the mechanosensory neurons. The relevance of this to the ability of at least some abraded dactyl setae to remain functional in a long-lived, nonmolting crab is considered.

Postlarval changes in the external morphology of dactyl setae in the kelp crab, Pugettia producta (randall)

AbstractMorphological changes, which include growth, encrustation, and abrasion, occur in the sensory setae and nonsensory denticles located on the dactyls of the walking legs during the postlarval development of the kelp crab, Pugettia producta (Randall). The growth of the denticles is isometric (slope ∼ 1), while the growth of the setae is negatively allometric (slope < 1), relative to the growth of the dactyls. The increase in the sizes of the setae, but not of the denticles, appears to slow before growth stops at maturation, when molting ceases. The most striking morphological changes in the setae occur after maturation. While the setae of all but recently molted juvenile crabs are heavily encrusted by epibionts, the dactyls of most mature crabs are clean, and both the setae and denticles are so abraded that only their bases remain. The consequences of these morphological changes are discussed in relation to the sensory capabilities of a long‐lived, nonmolting majid crab.

A topographical and typological comparison of the rodlike setae of ambulatory dactylopodites in decapod crustaceans.

The arrangement and external morphology of the rodlike setae and associated structures located on the dactylopodites of the walking legs of six species of decapod crustaceans are compared. The dactyls of littoral species, represented by the rock crab, Cancer antennarius, and the spiny lobster, Panulirus interruptus, have dense tufts and bands of rodlike setae, as is typical of many decapods, and additionally only a few small plumed setae. The arrangement of setae on the dactyls of the recently discovered Galapagos vent crab, Bythograea thermydron, closely resembles that of C. antennarius. Rodlike and long plumed setae occur in about equal numbers on the dactyls of the pelagic anomuran, Pleuroncodes planipes. The dactyls having the fewest rodlike setae are those of the terrestrial hermit crab, Coenobita perlatus, and those of the kelp crab, Pugettia producta, where flat setae typical of Majidae have replaced most rodlike setae. The presence and structures of the terminal pores in rodlike setae vary intra- and interspecifically, possibly as a function of molt stage. Variations in some features of rodlike setae, such as tip acuity and presence of microsetae and surface sculpting, appear to be related to development. Serrated setae occur on the dactyls of megalopal P. producta but not in later stages. The topography and typology of setae located on the ambulatory dactyls of decapod crustaceans are considered in light of recent interest in using setal characteristics to determine the sensory functions of sensilla and to clarify the phylogeny of arthropod groups.

Organization of food search in the kelp crab, Pugettia producta (Randall)

Food search was activated by chemical stimuli in specimens of the kelp crab, Pugettia producta (Randall). No differences were found between laboratory-and field-tested animals. In both, food search consisted of two components: near field (non-locomotor leg and chela probing) and far field (locomotion) search. Leg and chela probing were initiated at threshold concentrations one log unit or more below that of locomotion and were initiated prior to and in the absence of locomotion. Locomotion was limited in its activation to instances in which leg and chela probing were first initiated but failed to contact food. These results indicate that chemosensory stimuli selectively activate nearby rather than distant food search. Up to 14 days of food deprivation failed to alter this response hierarchy and threshold concentrations for near field search acts were identical for satiated and starved animals.

Foraging strategies and prey switching in the California sea otter.

Southern sea otters (Enhydra lutris nereis), in recovering from near extinction, are gradually extending their range to include areas from which they have been absent for more than one hundred years. This study took advantage of the otters' relatively sudden arrival in the area near Santa Cruz, California, to monitor their prey selection in the first two years of residence there. Foraging observations revealed that sea urchins (Strongly-locentrotus franciscanus) were heavily preyed upon initially, but virtually disappeared from the diet after one year of sea otter residence. The disappearance of sea urchins was accompanied by an increased use of kelp crabs (Pugettia producta) and the appearance of clams (Gari californica) in the otters' diet. Abalones (Haliotis rufescens) and cancer crabs (Cancer spp.) remained fairly stable as dietary items throughout the two year period. An electivity index was used to quantify sea otter preferences, which corresponded closely with a ranking scheme based on energy intake/unit foraging time calculated for each major prey species. As predicted by optimal foraging theory, sea otters prefer food species of high rank and replace depleted dietary items with those of next highest rank. The process of dietary switching was analyzed with respect to foraging success rates, and it appears that poor success rates, associated with predation on an increasingly rarer prey species (sea urchins), drive sea otters to hunt for different prey. Both patch selection and search image formation appear to function in this process. The potential effects on community structure and stability of predators exhibiting a preference for the most profitable prey are discussed.

Algal Preferences for Decoration By the Californian Kelp Crab, Pugettia Producta (Randall) (Decapoda, Majidae)

L'opinion courante sur les crabes decorateurs appartenant a la superfamille des Oxyrhyncha veut que ces crabes selectionnent au hasard le materiel pour decorer parmi ce qui se trouve dans leur environnement. Cependant le juvenile de Pugettia producta montre une preference evidente, dans son choix, pour des especes specifiques d'algues. En laboratoire ces crabes montrent une preference pour une algue a la fois comme source de nourriture et comme materiel de decoration. En laboratoire egalement le comportement de decoration semble lie a la fonction d'alimentation plutot qu'a la protection offerte par l'effet de camouflage.

Chitin-bound keto-carotenoids in a crustacean carapace

1. 1. Chitinous parts from the carapace of the red kelp crab, Taliepus nuttallii, yielded no or negligible pigment to common organic solvents (save to pyridine) and/or protein denaturants unless first decalcified. 2. 2. Hot aqueous acetic acid readily decalcified the shell and extracted all pigment, which was resolved into but four fractions, in the following order of increasing proportion and decreasing polarity; astaxanthin, phoenicoxanthin, canthaxanthin and echinenone, all of which had been firmly bonded to chitin.

Behavioral Responses to Electrolytes in the Crayfish, Procambarus clarkii

Previous articleNext article No AccessBehavioral Responses to Electrolytes in the Crayfish, Procambarus clarkiiMary W. Pocock and James L. LarimerMary W. Pocock Search for more articles by this author and James L. Larimer Search for more articles by this author PDFPDF PLUS Add to favoritesDownload CitationTrack CitationsPermissionsReprints Share onFacebookTwitterLinkedInRedditEmail SectionsMoreDetailsFiguresReferencesCited by Volume 41, Number 3Jul., 1968 Article DOIhttps://doi.org/10.1086/physzool.41.3.30155465 Views: 2Total views on this site Citations: 2Citations are reported from Crossref Journal History This article was published in Physiological Zoology (1928-1998), which is continued by Physiological and Biochemical Zoology (1999-present). Copyright 1968 University of ChicagoPDF download Crossref reports the following articles citing this article:R.K. Zimmer, D.P. Cook, J.F. Case Chemosensory induced bradycardia in the kelp crab, Pugettia producta (Randall), Journal of Experimental Marine Biology and Ecology 38, no.22 (Apr 1979): 135–150.https://doi.org/10.1016/0022-0981(79)90017-0James L. Larimer Command Interneurons and Locomotor Behavior in Crustaceans, (Jan 1976): 293–326.https://doi.org/10.1007/978-1-4757-0964-3_12

Total and Tissue Respiration in Relation to Body Weight a Comparison of the Kelp Crab with Other Crustaceans and with Mammals

Total and Tissue Respiration in Relation to Body Weight a Comparison of the Kelp Crab with Other Crustaceans and with Mammals

Studies on the Metabolism of Marine Invertebrate Tissue I. Respiration of the Midgut Gland of the Kelp Crab (Pugettia producta)

Previous articleNext article No AccessStudies on the Metabolism of Marine Invertebrate Tissue I. Respiration of the Midgut Gland of the Kelp Crab (Pugettia producta)Harwood S. Belding, John Field II, Frank W. Weymouth, and Shannon C. AllenHarwood S. Belding Search for more articles by this author , John Field II Search for more articles by this author , Frank W. Weymouth Search for more articles by this author , and Shannon C. Allen Search for more articles by this author PDFPDF PLUS Add to favoritesDownload CitationTrack CitationsPermissionsReprints Share onFacebookTwitterLinkedInRedditEmail SectionsMoreDetailsFiguresReferencesCited by Volume 15, Number 1Jan., 1942 Article DOIhttps://doi.org/10.1086/physzool.15.1.30151635 Views: 2Total views on this site Citations: 2Citations are reported from Crossref Journal History This article was published in Physiological Zoology (1928-1998), which is continued by Physiological and Biochemical Zoology (1999-present). PDF download Crossref reports the following articles citing this article: Frederick A. Fuhrman , Nell Hollinger , Jefferson M. Crismon , John Field II , and F. W. Weymouth The Metabolism of the Excised Brain of the Largemouthed Bass (Huro Salmoides) at Graded Temperature Levels, Physiological Zoology 17, no.11 (Sep 2015): 42–50.https://doi.org/10.1086/physzool.17.1.30151828 F. W. Weymouth , J. M. Crismon , V. E. Hall , H. S. Belding , and John Field II Total and Tissue Respiration in Relation to Body Weight a Comparison of the Kelp Crab with Other Crustaceans and with Mammals, Physiological Zoology 17, no.11 (Sep 2015): 50–71.https://doi.org/10.1086/physzool.17.1.30151829

The nervous system of the kelp crab, Pugettia producta

The nervous system of the kelp crab, Pugettia producta