scholarly journals GRAVITY AND LIGHT INFLUENCE THE COUNTERSHADING REFLEXES OF THE CUTTLEFISH SEPIA OFFICINALIS

1994 ◽  
Vol 191 (1) ◽  
pp. 247-256
Author(s):  
G Ferguson ◽  
J Messenger ◽  
B Budelmann
Keyword(s):  
Anterior Part ◽  
Posterior Part ◽  
Angular Acceleration ◽  
Ventral Surface ◽  
The Body ◽  
Gravity Receptor ◽  
Bilateral Destruction ◽  
The Brain ◽  
Ventral Edge ◽  
Angle Of Rotation

Rotation (roll or pitch) of a cuttlefish away from its normal orientation produces countershading reflexes (CSRs) that consist of chromatophore expansion on the ventral body surface. When rotation is in the roll plane, the CSR has two components on each side of the body. The first (component A) consists of a unilateral expansion of chromatophores on the uppermost latero-ventral edge of the mantle, the underside of the upper fin and the uppermost side of the head; it occurs when the angle of rotation is less than 90°. Further rotation (from approximately 90° to approximately 180°) adds the second component (component B): a unilateral expansion of the chromatophores on the upper half of the ventral surface of the mantle, funnel, head and arms. When rotation is in the pitch plane, chromatophores expand on the posterior part of the ventral mantle and fins when the head is down; when the head is up, chromatophores expand on the ventral surface of the arms, head and funnel and on the anterior part of the ventral mantle and fins. The pitch CSR is always bilateral. Destruction of the gravity or the angular acceleration receptor systems of the statocysts demonstrates that it is the gravity receptor systems that drive the CSRs. Unilateral destruction of the gravity receptor systems shows that the pitch CSR is driven bilaterally, whereas the roll CSR is driven unilaterally. Components A and B of the roll CSR are driven by input from the ipsilateral statocyst, but component A is additionally driven by light. Brain lesions provide evidence that the pathways for the CSRs run through the lateral basal lobes in the supraoesophageal part of the brain.

scholarly journals The anatomy of symmetrical double monstrosities in the trout

1901 ◽  
Vol 68 (442-450) ◽  
pp. 129-134 ◽  
Keyword(s):  
Anterior Part ◽  
Posterior Part ◽  
Yolk Sac ◽  
The Body ◽  
Special Adaptation ◽  
Structural Details ◽  
Complete Series

This paper contains the results of an investigation into the anatomy of a series of trout embryos exhibiting different degrees of symmetrical duplicity, and gives an account of the structural details which attend the fusion, disappearance, or special adaptation of parts in the region of transition from the double to the single condition. Some general questions suggested by these results are also discussed. The monstrosities examined were four months old counting from the time of fertilisation, and they form a fairly complete series ranging from specimens in which the duplicity does not affect more than the anterior part of the head to specimens in which there is union by the posterior part of the body or by the yolk-sac only.

Acrostichus puri n. sp. (Nematoda: Diplogastridae), a phoretic associate of Augochlora pura mosieri Cockerell (Hymenoptera: Halictidae)

Nematology ◽  
2010 ◽  
Vol 12 (1) ◽  
pp. 49-64 ◽  
Author(s):  
Yongsan Zeng ◽  
W. Kelley Thomas ◽  
Natsumi Kanzaki ◽  
Barbara Center ◽  
Robin Giblin-Davis ◽  
...  
Keyword(s):  
New Species ◽  
Anterior Part ◽  
Posterior Part ◽  
The Body ◽  
Sweat Bee ◽  
Molecular Sequence ◽  
Female Tail ◽  
Triangular Flap ◽  
Mating Tests

AbstractAcrostichus puri n. sp., isolated from the body of a sweat bee, Augochlora pura mosieri, is described and figured. The new species is morphologically, molecularly and biologically very similar to A. halicti, i.e., these two species share a very complicated gubernaculum structure, distally hooked spicules with a triangular flap-like rostrum, stomatal polymorphism and synchronised associations with halcitid bees. The new species can be distinguished from A. halicti by its spicule morphology, distinctive squared manubrium and sharply bent (= ca 90° or L-shaped) distal tip vs an indistinctive rounded manubrium and a strongly recurved (= ca 180° or U-shaped) distal tip; gubernaculum with narrower, longer, anterior part and more complex posterior part than A. halicti, and tail of both sexes, with a long and filiform spike on the male or female tail vs a short spike (male) or conical tail (female). These two species also differ from each other by significant molecular sequence differences in SSU (2.0%), D2/D3 LSU (4.5%) and mtCOI (9.2%), and are reproductively incompatible in mating tests.

Course of the Peripheral Gustatory Nerves

1977 ◽  
Vol 86 (2) ◽  
pp. 251-258 ◽  
Author(s):  
Heinz Rollin
Keyword(s):  
Facial Nerve ◽  
Medulla Oblongata ◽  
Trigeminal Nerve ◽  
Soft Palate ◽  
Cranial Nerve ◽  
Anterior Part ◽  
Posterior Part ◽  
Greater Superficial Petrosal Nerve ◽  
The Brain

The multiple variations of the course of the gustatory nerves still considered possible are discussed. Recent investigations lead to the conclusion that there is only one path for the gustatory fibers for each gustatory area: 1) from the anterior part of the tongue via the tympanic cord and facial nerve to the medulla oblongata; 2) for the posterior part of the tongue in the IX cranial nerve; and 3) from the soft palate via the greater superficial petrosal nerve to the facial nerve. The trigeminal nerve carries no gustatory fibers to the brain.

scholarly journals Histological and Morphometrical Study of the Filiform Papillae in the Domestic Rabbit (Oryctolagus cuniculus)

2021 ◽  
Vol 78 (1) ◽  
pp. 63
Author(s):  
Mircea CIPOU ◽  
Cristian MARTONOS ◽  
Adrian Florin GAL ◽  
Vasile RUS ◽  
Ion VLASIUC ◽  
...  
Keyword(s):  
Anterior Part ◽  
Posterior Part ◽  
Dorsal Surface ◽  
Maximum Level ◽  
Body Part ◽  
The Body ◽  
Domestic Rabbit ◽  
Mixed Breed ◽  
Filiform Papillae ◽  
Morphometrical Study

The domestic rabbit is often preferred as an experimental model in diverse research and especially those regarding pathologies of the oral cavity, both in human and veterinary medicine. From five domestic mixed breed rabbits, fragments were harvested from the three regions of the tongue: apex, body and root, for histological investigations. The samples were processed by embedding in paraffin, sectioned at a thickness of 5 µm and stained with Goldner’s trichrome method. The histological examination highlighted the presence of the filiform papillae on the entire dorsal surface of the tongue, with morphological particular carachteristics for each portion. The dimension of the filiform papillae of the rabbit’s tongue differs both regarding the length as well as the thickness and density. The shortest filiform papillae were found on the tip of the tongue, then the length increases progressively, reaching the maximum level on the middle portion and decreases in the last portion. The density also differs, in in the three compartments examined, being the highest in the anterior part and the lowest in the posterior part. The thickness of the filiform papillae is inversely proportional to their density. The thickness of the papillae is smaller where the density is higher and highest where the density is lowest. The upper surface of the filiform papillae is variably keratinized depending on the lingual segment. The papillae with the highest level of keratinization are arranged in the body part of the tongue, and those at the tip and root are slightly lower.

scholarly journals The Function of the Anal Gills of the Mosquito Larva

1933 ◽  
Vol 10 (1) ◽  
pp. 16-26 ◽  
Author(s):  
V. B. WIGGLESWORTH
Keyword(s):  
Carbon Dioxide ◽  
Body Surface ◽  
Mosquito Larva ◽  
Anterior Part ◽  
Pure Water ◽  
Posterior Part ◽  
The Body ◽  
Glycerol Water ◽  
Hypertonic Solutions ◽  
Spontaneous Aggregation

The anal gills of the mosquito larva (Aedes argenteus) are the only region of the body that is freely permeable to water. In hypertonic solutions of sugar or glycerol, water is extracted from the gills and the larva shrinks. In pure water this is absorbed by the gills and later excreted by the Malpighian tubes. The absorption of water appears to be effected mainly by osmosis. Larvae can mature without the gills, but they seem to grow more slowly, and show almost no parenteral absorption of water. Normally the larva swallows very little fluid. The fluid in the gut is probably secreted in the posterior part of the mid-gut and reabsorbed in the anterior part and in the caeca. Some of the water excreted by the Malpighian tubes is reabsorbed in the rectum. As judged by the spontaneous aggregation of the flagellate Polytoma, oxygen is absorbed by submerged larvae all over the body surface, but most actively at the base of the gills. Carbon dioxide is given off equally all over the body surface. It is concluded that the anal gills are primarily water-absorbing organs, and are only incidentally concerned in respiration.

scholarly journals Topographic and anatomical features of the sulci structure of the brain's occipital lobe medial surface

2019 ◽  
Vol 84 (3) ◽  
pp. 9-15
Author(s):  
O.O. Trach ◽  
D.M. Shyian ◽  
А.О. Tereshchenko ◽  
I.V. Ladna
Keyword(s):  
Anterior Part ◽  
Posterior Part ◽  
Occipital Lobe ◽  
Anatomical Structures ◽  
Anatomical Features ◽  
Medial Surface ◽  
Distal Process ◽  
Common Area ◽  
The Brain ◽  
Proximal Process

The complex of macromicroscopic methods has revealed the features of the sulci structure of the brain’s occipital lobe medial surface. Macromicroscopic, morphometric, topographic and anatomical, statistical and mathematical analysis were used. The sulci of the medial surface of the brain's occipital lobe are classified into permanent, typical and non-permanent. The complex of anatomical structures of the medial surface of the brain's occipital lobe includes the parietooccipital sulcus, calcarine sulcus, cuneus, calcarine spur, additional sulci. The parietooccipital and calcarine sulci are divided into segments: posterior (distal process), anterior (proximal process), common (common area). The parietooccipital sulcus is connected to the anterior end of the calcarine sulcus at 98,5 %. The length of the parietooccipital sulcus is min 16,0 mm and max 58 mm, M=35,8 mm, depth is min 9,0 mm and max 43,0 mm, M=24,3 mm. It was found that in 35 % of cases, the posterior end of the calcarine sulcus does not reach the apex (angle) of the occipital lobe of the brain by min 2,0 mm and max 14,0 mm, M=7,8 mm. In 43 % the posterior end of the calcarine sulcus bifurcates. The distance between the posterior end of the calcarine sulcus and the upper end of the parietooccipital sulcus is min 18,0 mm and max 64,0 mm, M=39,8 mm. The length of the calcarine sulcus is min 37 mm and max 79 mm, M=54 mm. The depth of the anterior part of the calcarine sulcus is min 8,0 mm and max 36,0 mm, M=20,7 mm; the depth of the posterior part is min 5,0 mm and max 22,0 mm, M=12,8 mm.

scholarly journals Memoirs: Nephridia and Body-cavity of some Decapod Crustacea

1893 ◽  
Vol s2-34 (136) ◽  
pp. 403-426
Author(s):  
EDGAR J. ALLEN
Keyword(s):  
Nerve Cord ◽  
Anterior Part ◽  
Posterior Part ◽  
Body Cavity ◽  
The Body ◽  
Shell Gland ◽  
Central Cavity ◽  
Typical Structure ◽  
Pericardial Cavity ◽  
Dorsal Sac

1. The green gland of Palæmonetes (and Palæmon) at the time of hatching of the larva has not developed a lumen, although the external opening can be detected. When the larva leaves the egg the lumen commences to open, and the gland consists of an end-sac and a U-shaped tube, of which the distal portion gives rise to the bladder. The bladder then enlarges greatly, growing at first inwards towards the middle ventral line, then upwards, within the oesophageal nerve-ring and anterior to the oesophagus, to the middle dorsal line, where it meets its fellow of the opposite side. The two bladders grow backwards over the stomach and beneath the dorsal sac, subsequently fusing together in the middle line to form the unpaired nephro-peritoneal sac. 2. The shell-glands are the functional excretory organs at the time of hatching and during the latter part of the embryonal period. They open at the bases of the second maxillæ, and each consists of an end-sac and a Y-shaped renal tube, which have the typical structure of a crustacean nephridium. 3. A dorsal sac, which is completely enclosed by an epithelial lining, persists in adults of Palsem on, Palæmonetes, and Crangon. This sac, which does not contain blood, lies upon the nephro-peritoneal sac and the front end of the ovary, being much enlarged at its posterior end. The cephalic aorta (ophthalmic artery) lies within the dorsal sac. 4. At its anterior end the dorsal sac is surrounded by a mass of tissue which appears to be producing blood-corpuscles. 5. The dorsal sac is formed as a hollowing out in masses of mesoderm-cells, which lie on either side of the cephalic aorta. Two lateral cavities are thus formed, which increase in size and unite below the aorta. Taking into account this mode of development, a comparison with Peripatus shows that the dorsal sac is homologous with the dorsal portions of the mesoblastic somites of that animal, and must therefore be regarded as a true cœlom. 6. The body-cavity of these Crustaceans varies in different regions. (a) In the anterior part of the thorax it consists of a true cœlom (the dorsal sac and nephridia) and a hæmocœle. The hæmocœle consists of (1) a central cavity, in which the stomach and intestine, the liver and the nerve-cord lie; (2) two lateral cavities, which contain the end-sac and proximal end of the tube of the shell-gland, and which communicate with the central cavity and with the cavities of the legs; and (3) these leg-cavities, which, in the second maxillæ, contain the tube of the shell-gland. (b) In the posterior part of the thorax the body-cavity is entirely a hæmocœle. It consists of (1) the pericardial cavity, in which lies (2) the heart, and which is separated by the pericardial septum from (3) the central cavity of the body, which contains the genital organs, liver, intestine, and nerve-cord; (4) the lateral cavities, which communicate with the central cavity and with (5) the cavities of the legs. (c) In the abdomen the body-cavity is entirely a hæmocœle. It consists of a dorsal and a ventral sinus, which communicate with one another by lateral sinuses.

A new species of patch-nosed snake (Colubridae: Salvadora Baird and Girard, 1853) from Oaxaca, Mexico

Zootaxa ◽  
2019 ◽  
Vol 4564 (2) ◽  
pp. 588
Author(s):  
CARLOS ALBERTO HERNÁNDEZ-JIMÉNEZ ◽  
OSCAR FLORES-VILLELA ◽  
JONATHAN ATWOOD CAMPBELL
Keyword(s):  
New Species ◽  
Anterior Part ◽  
Posterior Part ◽  
The Body ◽  
Taxonomic Descriptions ◽  
A New Species

A new species of snake of the genus Salvadora from Oaxaca, Mexico, is described. This taxon was confused with S. intermedia in previous taxonomic descriptions. It is characterized by lacking a pale vertebral stripe and by having incomplete dorsolateral stripes that do not reach the posterior part of the body, which is typical of congeners; by having both dorsolateral stripes separated each other by five to six scale rows on anterior part of body; and other scalation characters as well as the number maxillary teeth. The importance of this snake and its conservation is discussed. 

The Effect of Splitting part of the Brain or Removal of the Median Inferior Frontal Lobe on Touch Learning in Octopus

1969 ◽  
Vol 50 (2) ◽  
pp. 515-526
Author(s):  
M. J. WELLS ◽  
J. Z. YOUNG
Keyword(s):  
Frontal Lobe ◽  
Anterior Part ◽  
Posterior Part ◽  
Tactile Discrimination ◽  
Learning Mechanism ◽  
Marked Preference ◽  
Smooth Objects ◽  
The Brain ◽  
Correct Discrimination ◽  
Good Transfer

1. Octopuses with the whole supraoesophageal lobe divided in the mid-line show a lesser preference for smooth objects than normals. 2. Learning of a simple successive tactile discrimination can proceed as fast in such a half-brain as in a whole brain. 3. Animals in which the anterior part of the supraoesophageal lobe alone was split also learned approximately as fast as normals. When tested on the untrained side they showed at most slight signs of ‘transfer’. The unsplit vertical lobe system apparently mediates little transfer, either of learning to take or not to take an object. 4. Animals with the posterior part of the supraoesophageal lobe alone split learned less well than normals or those with anterior splits, the deficit being due to the large number of takes of the negative object. Tests on the untrained side showed that good transfer of the capacity for positive and negative learned response occurred through the intact inferior frontal commissures. 5. Animals without the median inferior frontal lobe showed a marked preference for rough objects. Of six trained with smooth positive only two showed increasingly correct discrimination. Four out of seven animals trained with rough positive showed an increasingly correct performance as a result of training. The performance of the others got worse as training proceeded. It is not clear whether this learning deficit is due to the excessive rough preference or to the absence of some part of the learning mechanism owing to removal of the median inferior frontal lobe. 6. Tests on the untrained side of animals without median inferior frontal show no capacity to discriminate. This shows that the median inferior frontal is vital to lateral transfer and confirms that learning cannot readily be transferred through the vertical lobe system.

Fasciola gigantica: surface topography of the adult tegument

2001 ◽  
Vol 75 (1) ◽  
pp. 43-50 ◽  
Author(s):  
T. Dangprasert ◽  
W. Khawsuk ◽  
A. Meepool ◽  
C. Wanichanon ◽  
V. Viyanant ◽  
...  
Keyword(s):  
Anterior Part ◽  
Ventral Side ◽  
Ventral Surface ◽  
Dorsal Side ◽  
Fasciola Gigantica ◽  
The Body ◽  
Lateral Aspect ◽  
Tegumental Surface ◽  
Type 3

Adult Fasciola gigantica are leaf-shaped with tapered anterior and posterior ends and measure about 35 mm in length and 15 mm in width across the mid section. Under the scanning electron microscope its surface appears rough due to the presence of numerous spines and surface foldings. Both oral and ventral suckers have thick rims covered with transverse folds and appear spineless. On the anterior part of the ventral surface of the body, the spines are small and closely-spaced. Each spine has a serrated edge with 16 to 20 sharp points, and measures about 20 μm in width and 30 μm in height. In the mid-region the spines increase in size (up to 54 μm in width and 58 μm in height) and number, especially towards the lateral aspect of the body. Towards the posterior end the spines progressively decrease in both size and number. The tegumental surface between the spines appears highly corrugated with transverse folds alternating with grooves. At higher magnifications the surface of each fold is further increased with a meshwork of small ridges separated by variable-sized pits or slits. There are three types of sensory papillae on the surface. Types 1 and 2 are bulbous, measuring 4–6 μm in diameter at the base with nipple-like tips, and the type 2 also have short cilia. Type 3 papillae are also bulbous and of similar size but with a smooth surface. These sensory papillae usually occur in clusters, each having between 2 and 15 units depending on the region of the body. Clusters of papillae on the lateral aspect (usually types 1 and 2) and around the suckers (type 3) tend to be more numerous and larger in size. The dorsal side of the body exhibits similar surface features, but the spines and papillae appear less numerous and are smaller. Corrugation and invaginations of the surface are also less extensive than on the ventral side of the body.

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