(n.) One of the abdominal legs of a crustacean. See Illust. under Crustacea.
Example Sentences:
(1) C. californiensis, when placed in simulated burrow conditions, regulates the PO2 very loosely in its immediate microhabitat, using its pleopods.
(2) During egg attachment, the pleopods beat vigorously and cause envelope 1 to stretch and form attachment stalks.
(3) Eggs pass over the ventral surface of spawning females to the region of the pleopods, where they stick by means of layer 1A to each other and to the ovigerous setae.
(4) Muscle AEC did not change with molt stage, but levels of ATP (F = 8.050) and ADP (F = 4.130) were significantly higher in premolt (D3 pleopod stage 5.0-5.5) animals; while levels of arginine phosphate (F = 6.981) were significantly higher in post-molt animals.
(5) The rate of urine production, calculated from the half time for the loss of sodium diatriazoate is 11.8 mg in SW and 42.9 mg 24 h-1 100 mg-1 wet weight in 50% SW. 95% of the diffusion fluxes of water take place through the pleopods: their surface is about 62.6 mm2 in a 100 mg weighing animal.
(6) After the egg mass is secured to the ovigerous setae, envelope 1 of both the attachment stalk and egg coat condenses to form a tough material capable of securing the egg mass to the pleopods for intervals up to 16 months.
(7) -- The pleopods of some first and even second or third stage adults retain some setae.
(8) The pleopods of C. californiensis, a potential site for extrabranchial oxygen exchange, do not contribute significantly to oxygen consumption.
Swimmeret
Definition:
(n.) One of a series of flat, fringed, and usually bilobed, appendages, of which several pairs occur on the abdominal somites of many crustaceans. They are used as fins in swimming.
Example Sentences:
(1) Mechanosensory stimulation of an abdominal swimmeret initiates a fictive extension which includes flexion inhibition.
(2) The strongest extension response was produced at 2 Hz which falls within the normal range of swimmeret beating in intact lobsters.
(3) Feathered hair sensilla fringe both rami of the lobster (Homarus americanus) swimmeret.
(4) Proof that PTX acts by binding the GABA receptor was obtained by observing that the addition of GABA or muscimol to preparations pretreated with PTX did not affect either spontaneous or swimmeret evoked activities, or intracellular potential amplitudes.
(5) The sensilla on the male and female second swimmerets are sexually dimorphic.
(6) Evidence from extracellular analyses suggested that single interneurons of the abdominal nerve cord could produce motor outputs in both the swimmeret and the abdominal positioning systems.
(7) Localized tactile stimulation of the swimmeret surface with a mechanical probe usually generated flexion inhibition where the flexor inhibitor (f5) was activated while the small and medium flexor excitors were inhibited.
(8) DL-Octopamine inhibits the swimmeret system, both when the system is spontaneously active and when it has been excited by proctolin.
(9) Physiological experiments in which RPCH was perfused into the ganglia of isolated nerve cords showed that RPCH modulated the swimmeret rhythm.
(10) A study has been made of the interrelations between rhythmical exopodite beating in different larval stages and swimmeret beating in poast-larval stages of the lobster Homarus gammarus.
(11) Female swimmerets contain many long "smooth hairs" (long simple setae) on the coxa and rami.
(12) The membrane potential of interneuron IA oscillated in phase with the swimmeret rhythm, a motor pattern generated in each of these ganglia, because the neuron received postsynaptic potentials in phase with the rhythm.
(13) Differences emerge in the performance of larval exopodites and post-larval swimmerets (table 6b), although the possibility cannot be excluded that the larval exopodite oscillator in some way influences the developing action of the post-larval swimmeret system.
(14) The response properties of both types of hypodermal mechanoreceptors imply that they are activated during the characteristic beating movements of the swimmerets.
(15) The swimmerets in the abdomen of the lobster Homarus americanus are paired external appendages whose back and forth propulsive movements are brought about largely by a group of power and return stroke muscles located in the lateral abdominal cavity.
(16) None of the dual output neurons examined influenced the swimmeret motoneurons directly.
(17) Gas chromatographic analysis of hepatopancreas and swimmeret muscle tissue of dead and dying crabs revealed total DDT residue concentrations as high as 39.0 ppm and 1.43 ppm, respectively.
(18) Phentolamine also blocks inhibition of the swimmeret system by inhibitory command interneurons.
(19) The sensory response to hair displacement was characterized by recording afferent impulses extracellularly from the swimmeret sensory nerve while deflecting sensilla with a rigidly-coupled probe or controlled water movements.
(20) In nerve cords that were spontaneously producing the swimmeret rhythm, RPCH lengthened both the period and the duration of bursts of action potentials, but did not alter the phase relationships between bursts in different segments.