Memoirs: On the Reproductive Processes of the Earthworm, Lumbricus Terrestris

1925 ◽  
Vol s2-69 (274) ◽  
pp. 245-290
Author(s):  
A. J. GROVE
Keyword(s):  
Body Wall ◽  
Seminal Fluid ◽  
Lumbricus Terrestris ◽  
The Body ◽  
The Other ◽  
Reproductive Processes ◽  
Longitudinal Muscles ◽  
Earthworm Lumbricus

During the sexual congress of L.terrestris, the co-operating worms become attached to one another in a head-to-tail position in such a way that segments 9-11 of one are opposed to the clitellum of the other, and vice versa. At these points the attachment between the worms is an intimate one, assisted by the secretion of the glands associated with the diverticula of the setal pores found in certain segments, and is reinforced by the mutual penetration of the setae into the opposed body-surfaces. There is also a slighter attachment between segment 26 of one and 15 of the other. Each worm is enclosed in a slime-tube composed of mucus secreted from the epidermis. The exchange of seminal fluid is a mutual one. The fluid issues from the apertures of the vasa deferentia in segment 15, and is conducted beneath the slime-tube in pit-like depressions in the seminal grooves, which extend from segment 15 to the clitellum on each side of the body, to the clitellum, where it accumulates in the space between the lateral surfaces of segments 9-11 of one worm and the clitellum of the other. Eventually it becomes aggregated into masses in the groove between segments 9 and 10, and 10 and 11, and passes thence into the spermathecae. The seminal groove and its pit-like depressions are brought into existence by special muscles lying in the lateral blocks of longitudinal muscles of the body-wall.

Kinematic scaling of locomotion by hydrostatic animals: ontogeny of peristaltic crawling by the earthworm lumbricus terrestris

1999 ◽  
Vol 202 (6) ◽  
pp. 661-674 ◽  
Author(s):  
K.J. Quillin
Keyword(s):  
Body Mass ◽  
Body Wall ◽  
Deformable Body ◽  
Lumbricus Terrestris ◽  
The Body ◽  
Duty Factor ◽  
Body Segments ◽  
The Relationship ◽  
Dynamic Shape ◽  
Earthworm Lumbricus

This study examined the relationship between ontogenetic increase in body size and the kinematics of peristaltic locomotion by the earthworm Lumbricus terrestris, a soft-bodied organism supported by a hydrostatic skeleton. Whereas the motions of most vertebrates and arthropods are based primarily on the changes in the joint angles between rigid body segments, the motions of soft-bodied organisms with hydrostatic skeletons are based primarily on the changes in dimensions of the deformable body segments themselves. The overall kinematics of peristaltic crawling and the dynamic shape changes of individual earthworm segments were measured for individuals ranging in body mass (mb) by almost three orders of magnitude (0.012-8.5 g). Preferred crawling speed varied both within and among individuals: earthworms crawled faster primarily by taking longer strides, but also by taking more strides per unit time and by decreasing duty factor. On average, larger worms crawled at a greater absolute speed than smaller worms (U p2finity mb0.33) and did so by taking slightly longer strides (l p2finity mb0.41, where l is stride length) than expected by geometric similarity, using slightly lower stride frequencies (f p2finity mb-0.07) and the same duty factor (df p2finity mb-0.03). Circumferential and longitudinal body wall strains were generally independent of body mass, while strain rates changed little as a function of body mass. Given the extent of kinematic variation within and among earthworms, the crawling of earthworms of different sizes can be considered to show kinematic similarity when the kinematic variables are normalized by body length. Since the motions of peristaltic organisms are based primarily on changes in the dimensions of the deformable body wall, the scaling of the material properties of the body wall is probably an especially important determinant of the scaling of the kinematics of locomotion.

scholarly journals THE STRUCTURE OF THE SMOOTH MUSCLE FIBRES IN THE BODY WALL OF THE EARTHWORM

1957 ◽  
Vol 3 (1) ◽  
pp. 111-122 ◽  
Author(s):  
Jean Hanson
Keyword(s):  
Smooth Muscle ◽  
Phase Contrast ◽  
Body Wall ◽  
Longitudinal Muscle ◽  
Lumbricus Terrestris ◽  
Mirror Image ◽  
The Body ◽  
The Other ◽  
Muscle Fibres ◽  
Muscle Coat

1. The structure of the smooth muscle fibres in the longitudinal muscle coat of the body wall of Lumbricus terrestris has been investigated by phase contrast light microscopy and electron microscopy. 2. The muscle fibre is ribbon-shaped, and attached to each of its two surfaces is a set of myofibrils. These are also ribbon-shaped, and they lie with their surfaces perpendicular to the surfaces of the fibre, and their inner edges nearly meeting in the middle of the fibre. These fibrils are oriented at an angle to the fibre axis, and diminish greatly in width as they approach the edge of the fibre. The orientation of the set of fibrils belonging to one surface of the fibre is the mirror image of that of the set belonging to the other surface; thus, when both sets are in view in a fibre lying flat on one face, the fibre exhibits double oblique striation. A comparison of extended and contracted fibres indicates that as the fibre contracts, the angle made between fibre and fibril axes increases (e.g. from 5 to 30°) and so does the angle made between the two sets of fibrils (e.g. from 10 to 60°). 3. The myofibril, throughout its length, contains irregularly packed filaments, commonly 250 A in diameter, which are parallel to its long axis and remain straight in contracted muscles. Between them is material which probably consists of much finer filaments. Thus A and I bands are absent. 4. Bound to one face of each fibril, but not penetrating inside it, is a regularly spaced series of transverse stripes. They are of two kinds, alternating along the length of the fibril, and it is suggested that they are comparable to the Z and M lines of a cross-striated fibril. The spacing of these stripes is about 0.5 µ ("Z" to "Z") in extended muscles, and 0.25 µ in contracted muscles. A bridge extends from each stripe across to the stripeless surface of the next fibril.

The Action of Drugs, Especially Acetylcholine, on the Annelid Body Wall (Lumbricus, Arenicola)

1939 ◽  
Vol 16 (3) ◽  
pp. 251-257
Author(s):  
K. S. WU
Keyword(s):  
Skeletal Muscle ◽  
Spontaneous Activity ◽  
Body Wall ◽  
Lumbricus Terrestris ◽  
The Body ◽  
Arenicola Marina ◽  
Earthworm Gut ◽  
Mammalian Intestine ◽  
Earthworm Lumbricus ◽  
Vertebrate Skeletal Muscle

1. The actions of certain drugs (acetylcholine, eserine, atropine, nicotine, adrenaline) on strips of the body wall of the earthworm (Lumbricus terrestris) and lugworm (Arenicola marina) are described. 2. The body wall of the earthworm and lugworm resembles the dorsum of the leech, and also vertebrate skeletal muscle, in the following points: relatively insensitive to acetylcholine alone, sensitivity to acetylcholine greatly increased by eserine, response to acetylcholine abolished by nicotine. In these points, the muscles mentioned contrast with the earthworm gut and the mammalian intestine, which are: very sensitive to acetylcholine alone, sensitivity not greatly increased by eserine, response to acetylcholine abolished by atropine. 3. The various types of body wall strip differ among themselves as regards spontaneous activity, response to eserine alone, and response to adrenaline.

Locomotion and Coelomic Pressure in Lumbricus Terrestris L

1969 ◽  
Vol 51 (1) ◽  
pp. 47-58
Author(s):  
M. K. SEYMOUR
Keyword(s):  
Internal Pressure ◽  
Body Wall ◽  
Circular Muscle ◽  
Lumbricus Terrestris ◽  
The Body ◽  
Initial Penetration ◽  
Cine Film ◽  
Body Wall Muscles ◽  
Longitudinal Muscles ◽  
Do So

1. Crawling movement and burrowing of Lumbricus terrestris (L.) have been studied by continuous recording of internal pressure, direct observation and analysis of cine film. Frequency of locomotory waves is from 5 to 20 per min. Timing of protrusion of setae and of backward slip of points d'appui in locomotion have been observed and recorded. 2. In normal locomotion elongation of segments by contraction of the circular muscles gives rise to a discrete pressure pulse; shortening, by contraction of the longitudinal muscles, may or may not do so, depending on the position of the segment in the worm and the relative extent of contraction of the longitudinal and circular muscles. 3. Consideration of crawling and burrowing pressure records emphasizes the importance of (a) the circular muscles in extension of the head end in crawling and in initial penetration of the soil, and (b) the longitudinal muscles during burrowing, in dilating the burrow and drawing in more posterior segments 4. Mean pressures at circular and longitudinal muscle contraction are 12 and 7 cm. H2O respectively. The highest pressure recorded was 75 cm. H2O and accompanied violent squirming with evident contraction of all the body wall muscles. Resting pressures, shown in the absence of organized movement, are low (mean 0.26 cm. H2O). In both resting and crawling negative pressures sometimes occur and these are considered in relation to the inherent stiffness of the body wall and to the septate condition. 5. Tension in the longitudinal and circular muscle layers of a worm developing 75 cm. H2O internal pressure are calculated to be 265 and 1323 g./cm2. respectively, demonstrating in this example that, relative to the circulars, the longitudinal muscles are understressed by a factor of 5. Mean locomotory L.M. and C.M. peak values yield tension values of only 25 and 212 g./cm. respectively, and these are clearly well within the worm's capacity.

Stretch-sensitive neural units in the body wall of the earthworm, Lumbricus terrestris L

1976 ◽  
Vol 65 (1) ◽  
pp. 39-50
Author(s):  
C. D. Drewes ◽  
C. R. Fourtner
Keyword(s):  
Body Wall ◽  
Lumbricus Terrestris ◽  
Spike Frequency ◽  
The Body ◽  
Frequency Sensitivity ◽  
Segmental Nerve ◽  
Longitudinal Stretch ◽  
Sensory Neural ◽  
Earthworm Lumbricus

1. Sensory neural units responding to sinusoidal stretching of the body wall were studied in the earthworm, Lumbricus terrestris L. 2. A phasic stretch-sensitive unit found in segmental nerve I responded optimally to stretching at frequencies of 4-6/min. 3. The number of spikes per stretch and the spike frequency in the unit were directly related to the amplitude of the applied stretch within a range of 0-2-0-7 mm stretch/segment. 4. The ranges of amplitude and frequency sensitivity for the unit in isolated preparations corresponded closely to stretch parameters seen during peristaltic locomotion in intact animals. 5. Stretch-sensitive responses in segmental nerve II-III were more variable; some units responded to longitudinal stretch while others responded to relaxation.

Mediolateral somitic origin of ribs and dermis determined by quail-chick chimeras

Development ◽  
2000 ◽  
Vol 127 (21) ◽  
pp. 4611-4617 ◽  
Author(s):  
I. Olivera-Martinez ◽  
M. Coltey ◽  
D. Dhouailly ◽  
O. Pourquie
Keyword(s):  
Skeletal Muscles ◽  
Body Wall ◽  
Primitive Streak ◽  
Axial Skeleton ◽  
Lateral Compartment ◽  
The Body ◽  
The Other ◽  
Lateral Part ◽  
Respective Contribution ◽  
Epaxial Muscles

Somites are transient mesodermal structures giving rise to all skeletal muscles of the body, the axial skeleton and the dermis of the back. Somites arise from successive segmentation of the presomitic mesoderm (PSM). They appear first as epithelial spheres that rapidly differentiate into a ventral mesenchyme, the sclerotome, and a dorsal epithelial dermomyotome. The sclerotome gives rise to vertebrae and ribs while the dermomyotome is the source of all skeletal muscles and the dorsal dermis. Quail-chick fate mapping and diI-labeling experiments have demonstrated that the epithelial somite can be further subdivided into a medial and a lateral moiety. These two subdomains are derived from different regions of the primitive streak and give rise to different sets of muscles. The lateral somitic cells migrate to form the musculature of the limbs and body wall, known as the hypaxial muscles, while the medial somite gives rise to the vertebrae and the associated epaxial muscles. The respective contribution of the medial and lateral somitic compartments to the other somitic derivatives, namely the dermis and the ribs has not been addressed and therefore remains unknown. We have created quail-chick chimeras of either the medial or lateral part of the PSM to examine the origin of the dorsal dermis and the ribs. We demonstrate that the whole dorsal dermis and the proximal ribs exclusively originates from the medial somitic compartment, whereas the distal ribs derive from the lateral compartment.

A new genus and species of Sclerodactylidae (Echinodermata: Holothuroidea: Sclerothyoninae) from the Pacific coast of Panama, and assignment of Neopentamera anexigua to Sclerothyoninae

Zootaxa ◽  
2018 ◽  
Vol 4429 (1) ◽  
pp. 157
Author(s):  
LUCIANA MARTINS ◽  
MARCOS TAVARES
Keyword(s):  
Body Wall ◽  
New Genus ◽  
Pacific Coast ◽  
The Body ◽  
The Other ◽  
Monotypic Genus ◽  
New Genus And Species ◽  
The Pacific ◽  
Calcareous Ring

Paulayellus gustavi, a new sclerodactylid genus and species, is described from the Pacific coast of Panama. The new genus and species is assigned to the subfamily Sclerothyoninae based on a suite of characters, which include the radial and interradial plates of the calcareous ring united at the base only. Paulayellus gen. nov. differs from the other Sclerothyoninae genera in having posterior processesof radial plates undivided. Additionally, differs from Sclerothyone, Thandarum and Neopentamera in having knobbed buttons, plates and cups in the body wall (whereas the body wall is furnished only with tables and plates in Sclerothyone, Temparena and Thandarum, and only with knobbed buttons and plates in Neopentamera). The new genus is, so far, monotypic. The also monotypic genus Neopentamera proved to have the radial and the interradial plates of the calcareous ring united at the base only, as typically found in the Sclerothyoninae, and is therefore transferred to that subfamily. The discovery of a new genus in the Sclerothyoninae and the transfer of Neopentamera required the amendation of the diagnosis for the subfamily. A key to the Sclerothyoninae is given. 

Memoirs: On the Reproductive Processes of Earthworms: Part I. The Process of Copulation and Exchange of Sperms in Eutyphoeus waltoni Mich

1927 ◽  
Vol s2-71 (283) ◽  
pp. 479-502
Author(s):  
KARM NARAYAN BAHL
Keyword(s):  
Nutrient Medium ◽  
Seminal Fluid ◽  
The Other ◽  
Spermathecal Duct ◽  
Prostatic Fluid ◽  
Reproductive Processes ◽  
First Time ◽  
Male Genital

1. The method of exchange of the seminal fluid in Eutyphoeus is very simple and direct as compared with the elaborate process in Lumbricus. No intermediate structures like the clitellum and temporary seminal grooves take part in the process in Eutyphoeus. 2. During sexual congress, the co-operating worms become attached to one another in a head-to-tail position in such a way that the spermathecal apertures (7/8) of one are apposed to the penial segment (seventeenth) of the other and vice versa. 3. The male ‘genital pits’ are everted to form ‘genital cups’ and the penis is protruded. The genital cups produce a suction on the area of skin surrounding the spermathecal pores of the co-operating worm, and thus cause the formation of spermathecal papillae. In this way a ‘peg and socket’ joint is formed at four places in a copulating pair and, at each joint, the attachment is intimate, the genital cup closely embracing the spermathecal papilla and the penis penetrating the spermathecal duct. 4. There is a further attachment between the ventral surfaces of the two worms by means of permanent copulating papillae and temporary integumentary outgrowths. 5. The function of the penis as an intromittent organ in Eutyphoeus has been elucidated for the first time and a distinction has been made between ‘functional’ and ‘reserve’ penial setae. 6. The exchange of sperms is mutual. The penes inject both spermatic and prostatic fluids into the spermathecae. The sperms are invariably found in the diverticula and not in the ampulla, which probably contains a secretion of its own epithelium. There is some evidence to believe that the prostatic fluid serves a nutrient medium for the sperms in the seminal chambers of the diverticula.

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