Results 161 to 170 of about 1,256 (206)

The giant neurone system in ophiuroids

Cell and Tissue Research, 1981
The radial nerve cords of members of the class Ophiuroidea consist of two parts, the ectoneural and the hyponeural tissues, which are separated by an acellular basal lamina. The hyponeural tissue is composed entirely of motor fibres. The cell bodies of the hyponeural neurones are arranged in ganglia, one to each segment of the arm, and each containing ...
T R, Stubbs, J L, Cobb
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Electrophysiology and Luminescence of An Ophiuroid Radial Nerve

Journal of Experimental Biology, 1977
ABSTRACT All-or-none single unit spikes were recorded from an ophiuroid radial nerve cord. The spikes propagate non-decrementally over the entire radial nerve cord (RNC) length at rates as rapid as 78 cm−1. The neurones responsible for single unit activity reach lengths of 4−6 cm. Therefore, interneural transmission must occur for single
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Asteroids and Ophiuroids

1957
The asteroids (sea-stars) and ophiuroids (brittle stars) represent the two most successful divisions of the echinoderms of the present day. They both have retained the star-shaped body form, with no tendency toward the secondary bilateral symmetry found among the sea urchins and the holothurians.
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Neurosecretion in the Ophiuroid Ophiopholis aculeata

Science, 1962
Neurocrine activity has been demonstrated for the first time in the Ophiuroidea and for only the second time in the phylum Echinodermata. Three types of neurosecretory cells have been shown, by means of histological staining techniques, to occur in the principal motor ganglia.
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A new ciliary feeding structure in an ophiuroid echinoderm

Tissue and Cell, 1982
The genital shields which form the walls of the bursal slits in Ophiura texturata are covered by a precisely oriented arrangement of ciliated ridges and non-ciliated grooves. An electron microscopic examination has revealed many mucous cells associated with this structure and a catecholamine-containing nerve plexus underlying it.
T R, Stubbs, J L, Cobb
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On the stereom microstructure of ophiuroid teeth

Ophelia, 1996
Abstract The tooth stereom microstructure of 43 species of ophiuroids, from 9 families, was examined using light and scanning electron microscopy. Two basic types of teeth, uniform and compound, are present in ophiuroids. From a mechanical standpoint, compound teeth may provide a tougher grinding surface for ingestion of prey.
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Evolutionary paleoecology of dense ophiuroid populations

The Paleontological Society Papers, 1997
Issues of scale are becoming increasingly important to paleobiological interpretations of the fossil record. Nevertheless, a number of biological processes display scale-independent behaviors. The effects of predation on the distribution of dense populations of epifaunal, suspension-feeding ophiuroids are scale-independent, at scales ranging from the ...
Richard B. Aronson, Daniel B. Blake
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Predation on fossil and Recent ophiuroids

Paleobiology, 1987
The frequency of sublethal damage was examined in two ophiuroid species, Palaeocoma milleri and ? Ophioderma tenuibrachiata (Ophiodermatidae), from a shallow-water Jurassic “starfish bed.” None of 60 specimens was regenerating arms, a result that agrees
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Allelopathic potential of centipedegrass (Eremochloa ophiuroides)

Weed Science, 2006
Abstract Laboratory and greenhouse experiments were conducted to determine the allelopathic potential of centipedegrass. Germination and growth of indicator species were evaluated in soil leachates, leaf debris, and aqueous leaf extracts of centipedegrass.
Travis W. Gannon, Fred H. Yelverton, J. Scott McElroy   +2 more
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Interactions between ophiuroids and beaugregory damselfish

Journal of the Marine Biological Association of the United Kingdom, 2003
The interactions between beaugregory damselfish and ophiuroids, potential damselfish egg predators, were investigated using several field studies. A survey of back reef areas showed that the two most common ophiuroid species, Ophiocoma echinata and Ophioderma appressum, were significantly associated with the territories of beaugregory males within the ...
Adam G. Payne, Carl Smith, Andrew C. Campbell   +2 more
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