Structure and Permeability of Decapod Crustacea Cuticle

2015 ◽  
pp. 178-187 ◽  
Author(s):  
J. M. Lignon
Keyword(s):  
1969 ◽  
Vol 47 (3) ◽  
pp. 435-441 ◽  
Author(s):  
Valerie M. Pasztor

The mechanoreceptors of the respiratory appendage were studied by histological and electrophysiological techniques.A new type of mechanoreceptor is described and named the "oval organ". It consists of a specialized oval patch of cuticle 1–2 mm in length which is traversed by a spine or longitudinal thickening. Closely applied to the cuticle is a pad of connective tissue richly supplied with dendrites from two large nerve fibers. The orientation of the spine and the dendrites ensures that the receptor responds preferentially to certain stresses or foldings of the oval organ. It lies at the base of the scaphognathite on the dorsal surface.No internal proprioceptors were observed. Movements of the appendage are signalled either by the oval organ, epidermal receptors, or hair sensilla.The possible effect of sensory input upon the central respiratory rhythm generator is discussed.


1897 ◽  
Vol 21 (4-5) ◽  
pp. 237-257 ◽  
Author(s):  
M. I. Newbigin
Keyword(s):  

1947 ◽  
Vol 81 (800) ◽  
pp. 392-398 ◽  
Author(s):  
Martin D. Burkenroad

It has been shown (Yonge, 1932) that the integument of the Decapod Crustacea, as exemplified by the uncalcified lining of the foregut of the lobster, Homarus vulgaris , consists of two layers which differ widely in nature and origin. There is a thin superficial cuticle which is hyaline, possesses adsorbed lipin, and is formed by the widely distributed tegumental glands the function of which had previously been obscure. The actual chemical nature of this thin layer was not determined but it is not chitin from which it can be distinguished by a variety of chemical and physical tests. The underlying and much thicker layer of the integument consists of lamellated chitin formed by the cells of the epithelium. The present research was designed to determine in broad outline the permeability of this membranous integument, and in particular the influence upon this of the bounding cuticle and the general biological significance of the cuticle. In the Crustacea, Jordan and Lam (1918) found that the foregut and hindgut of Astacus , which are lined with chitin, behave as semipeimeable membranes, allowing water, but not dissolved substances, either electrolytes or non-electrolytes, to pass through under the influence of osmotic pressure. Similar results were obtained by Yonge (1924) with the foregut of Nephrops . Very different results were obtained from similar experiments with the midgut of both Astacus and Nephrops , indicating that the peculiar properties of the remainder of the gut are due to the chitinous lining. Murlin (1902) and Nicholls (1931) have shown that the chitin which lines the so-called midgut in Oniscus, Porcellio , and other land Isopoda, and in Ligia oceanica respectively, is permeable to the end-products of digestion. Krogh (1915) states that the gills of Astacus are practically impermeable to urethane. Fischel (1908), Koehring (1930, 1931), Gickelhorn (1931), and Bond (1933) have all found some evidence for the penetration of the integument of various Cladocera and Copepoda by vital stains.


1891 ◽  
Vol s2-32 (127) ◽  
pp. 279-291
Author(s):  
W.F. R. WELDON
Keyword(s):  

1978 ◽  
Vol 73 (1) ◽  
pp. 29-46
Author(s):  
F. Clarac ◽  
J. P. Vedel ◽  
B. M. Bush

In the decapod Crustacea, Palinurus vulgaris and Fasus lalandii, the reflex influences of one particular proprioceptor organ, the coxo-basal chordotonal organ (CB), on all the muscles operating the proximal and distal joints of the same leg, have been analysed. The distal end of CB was clamped in fine forceps mounted on a servo-controlled stretcher, and CB length changes of 2 mm were applied. Motor unit activity of the different muscles was recorded as electromyograms (EMGs). 1. Two types of proprioceptive reflex evoked by CB length changes have been investigated: (a) resistance reflexes of the two levator and two depressor muscles of the same leg segment, the coxopodite, i.e. ‘intrasegmental reflexes’, (b) ‘intersegmental reflexes’ induced in the muscles operating the proximal (T-C) joint of the same leg, and in all eight muscles of the limb segments distat to CB. 2. Both levator muscles respond reflexly to imposed CB stretch (which normally occurs with limb ‘depression’), while both depressors respond during CB shortening (or passive “elevation” of the leg). 3. Intersegmentally CB stretch reflexly activates the M-C extensor muscle, and sometimes facilitates the T-C remotor and C-P bender muscles. Shortening of the single CB organ of a leg excites one or two tonic motor units of the T-C promotor and M-C flexor muscles, and also facilitates the remotor, I-M reductor, and the single stretcher-opener excitatory motoneurone. 4. Some of the muscles, particularly the M-C flexor and extensor muscles, are also influenced intersegmentally by the resting length of CB, usually but not invariably in the same direction as for the corresponding dynamic reflexes. The role of the CB chordotonal organ is discussed, with particular consideration of its intersegmental reflex influence on the posture of the entire leg, and on the more complex motor behaviour of locomotion, where it may be specially significant in coordination of the limb in lateral walking. A complex picture of both tonic and dynamic, inra- and intersegmental reflex regulation of the positions and movements of the limb segments, thus emerges.


1971 ◽  
Vol 28 (10) ◽  
pp. 1527-1544 ◽  
Author(s):  
Josephine F. L. Hart

Three hermit crabs, Pagurus caurinus, P. quaylei, and P. stevensae, from British Columbia are described as new. Calastacus quinqueseriatus Rathbun, Paguristes ulreyi Schmitt, Pagurus cavimanus (Miers), P. samuelis (Stimpson), Parapagurus pilosimanus Smith, Munidopsis quadrata Faxon, and Chionoecetes tanneri Rathbun have not been recorded from the area between 48° and 55°N and 123° and 135°W, and also show considerable extensions of the known ranges. Within the confines of the same area, Callianassa gigas Dana, Paguristes turgidus (Stimpson), Pagurus cornutus (Benedict), P. hemphilli (Benedict), Orthopagurus minimus (Holmes), Petrolisthes cinctipes (Randall), Sceleroplax granulata Rathbun, Pinnotheres pugettensis Holmes, P. taylori Rathbun, and Planes marinus Rathbun are reported with extensions to known ranges. Pagurus capillatus (Benedict), P. tanneri (Benedict), Paralomis verrilli (Benedict), and Lithodes couesi Benedict are recorded, apparently for the first time from British Columbia, although known from both north and south of this area.


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