The external sensory morphology of the legs and hairplate system of female Trichogramma minutum Riley (Hymenoptera: Trichogrammatidae)

1987 ◽  
Vol 232 (1268) ◽  
pp. 323-366 ◽  
Keyword(s):  
Body Size ◽  
Neck Region ◽  
Dorsal Surface ◽  
Parasitoid Wasp ◽  
Ventral Surface ◽  
Distal Portion ◽  
The Body ◽  
Single Pair ◽  
Campaniform Sensilla ◽  
Trichogramma Minutum

This work continues a comprehensive description of the external sensory morphology of the parasitoid wasp Trichogramma minutum . All sensilla and associated structures identified by electron microscopy are described. In addition, this study also includes the hairplates associated with the antennae and neck region. The majority of sensilla appear to be mechanosensory, and are either trichoid or campaniform in structure. Large, socketed setae (10–50 μm long) are found on all leg segments, but vary considerably in body size and shape, depending upon location. On the tibial and tarsal segments of the pro- and metathoracic legs some of the larger hairs have been modified to form antennal and wing combs. On both the meso- and metathoracic legs a distal tibial seta is greatly enlarged and functions as a socketed spur. The sensilla that compose the hairplates are relatively short (1–3 μm) and differ in socket morphology from the longer setae located elsewhere on the body surface. Hairplates occur on the dorsal surface of the trochanter at the coxatrochanteral joint, on the distal portion of the coxae, around the neck on the dorsal and ventral surfaces of the episternum, and the opening of the postocciput. The most complex arrangement of hairplates surrounds the distal portion of the scape, and comprises four separate groups of hairs. Hairplates are also located on the dorsal and lateral surfaces of the proximal end of the pedicellus. Nine to eleven campaniform sensilla are located on the trochanter of each leg. The proximal subdivision of the femur is equipped with six sensilla grouped together on the ventral surface. Three to five campaniform sensilla are clustered on the dorsal surface of the distal end of the tibia of each leg, and a single pair of sensilla is located at the distal end of the first tarsomere. All the leg campaniform sensilla are elliptical, and 1.5–2.5 μm long. The number, position and morphology of the sensilla was consistent between individuals. The structure and function of these sensory structures are discussed in relation to their role in walking, proprioceptive control of posture, and gravity detection. The scaling of sensilla to body size and homologies with larger insects are also examined, and the possible role of these structures in the detection and measurement of host curvature is considered.

Morphology of Anomalocaris canadensis from the Burgess Shale

2014 ◽  
Vol 88 (1) ◽  
pp. 68-91 ◽  
Author(s):  
Allison C. Daley ◽  
Gregory D. Edgecombe
Keyword(s):  
Close Association ◽  
Dorsal Surface ◽  
Ventral Surface ◽  
The Body ◽  
Body Region ◽  
Morphological Description ◽  
Burgess Shale ◽  
Oral Cone ◽  
Stem Lineage ◽  
Posterior Body Region

Recent description of the oral cone of Anomalocaris canadensis from the Burgess Shale (Cambrian Series 3, Stage 5) highlighted significant differences from published accounts of this iconic species, and prompts a new evaluation of its morphology as a whole. All known specimens of A. canadensis, including previously unpublished material, were examined with the aim of providing a cohesive morphological description of this stem lineage arthropod. In contrast to previous descriptions, the dorsal surface of the head is shown to be covered by a small, oval carapace in close association with paired stalked eyes, and the ventral surface bears only the triradial oral cone, with no evidence of a hypostome or an anterior sclerite. The frontal appendages reveal new details of the arthrodial membranes and a narrower cross-section in dorsal view than previously reconstructed. The posterior body region reveals a complex suite of digestive, respiratory, and locomotory characters that include a differentiated foregut and hindgut, a midgut with paired glands, gill-like setal blades, and evidence of muscle bundles and struts that presumably supported the swimming movement of the body flaps. The tail fan includes a central blade in addition to the previously described three pairs of lateral blades. Some of these structures have not been identified in other anomalocaridids, making Anomalocaris critical for understanding the functional morphology of the group as a whole and corroborating its arthropod affinities.

Memoirs: The Development of the Serpiilid Pomatoeeros Triqueter L

1941 ◽  
Vol s2-82 (327) ◽  
pp. 467-540 ◽  
Author(s):  
F. SEGROVE
Keyword(s):  
Body Wall ◽  
Feeding Activity ◽  
Dorsal Surface ◽  
The Body ◽  
Single Pair ◽  
Feeding Apparatus ◽  
Food Material ◽  
Locomotor Apparatus ◽  
Adult Feeding ◽  
Branchial Crown

1. The larvae of Pomatoceros triqueter L. were obtained by artificial fertilization and reared through metamorphosis and for several months afterwards. Larval development took three weeks in summer, and about the same time in winter when the temperature was maintained at 65° F. 2. The eggs are small and give rise to typical trochosphere larvae with well-developed prototroch, metatroch, neurotroch, and feeding cilia, a spacious blastocoelic body-cavity and paired protonephridia. A head-vesicle and a conspicuous anal vesicle are also present. The right eye develops before the left. The larva is very active and grows rapidly at the expense of collected food material. 3. Three setigerous segments arise simultaneously; a fourth is added prior to metamorphosis. The lateral collar-folds develop in two capacious pockets which arise by invagination of the body-wall behind the metatroch, the ventral collar-fold by outgrowth of the ventral body-wall. The rudiments of the thoracic membrane appear above the lateral collar-folds. 4. Metamorphosis commences with the shrinkage of the locomotor apparatus, which leads to the exposure of the lateral collar-folds. The larva settles to the bottom and creeps about on its ventral surface by means of the neurotroch. The branchial crown arises as tripartite outgrowths on the sides of the head. The remaining tissues of the head, apart from the cerebral ganglion and eyes, are gradually resorbed. No tissue is thrown off. 5. The neurotroch gradually disappears and is replaced by cilia on the dorsal surface. The worm begins to secrete a calcareous tube. The resorption of the head is completed and the mouth assumes a terminal position surrounded by the branchial crown. 6. A fourth pair of filaments is added to the branchial crown. The dorsal pair of filaments develops into 'palps'. The third filament on the left side is modified as the operculum; the remaining filaments develop pinnules. 7. Further segments are added to the trunk. Those first added are of the thoracic type from the beginning. The eighth and succeeding setigers are of the abdominal type. The thoracic membrane gradually extends backwards to the posterior end of the thorax. 8. The thoracic nephridia arise as a single pair of cells which give rise to the dorsal unpaired duct by outgrowth. 9. The influence of the egg on the course of development is discussed. It is suggested: (a) that the small size of the egg is responsible for the active habits and protracted pelagic life of the larva; (b) that the mode of development of the collar is significant in that interference with the locomotor and feeding apparatus is thereby avoided; (c) that the general shrinkage which occurs at metamorphosis is related to a suspension of feeding activity in the period between the degeneration of the larval and the establishment of the adult feeding apparatus. 10. The development of Pomatoceros is compared with that of the Serpulid Psygmobranchus and the Sabeilid Branchiomma.

Studies on the growth and longevity of the yellow-bellied toad, Bombina variegata, in natural environments

1993 ◽  
Vol 14 (1) ◽  
pp. 35-44 ◽  
Author(s):  
Barbara Plytycz ◽  
Janusz Bigaj
Keyword(s):  
Body Size ◽  
Body Length ◽  
Cross Sections ◽  
Natural Environment ◽  
Early Life ◽  
Dorsal Surface ◽  
The Body ◽  
Natural Environments ◽  
Bombina Variegata ◽  
Different Parts

AbstractYellow-bellied toads were studied in their natural environment in a mountain locality in southeastern Poland. 608 specimens were captured, marked by yellow skin autografts placed in different parts of their dorsal surface according to body length, and released. Some of them were recaptured and measured from one to nine years later to estimate their growth and longevity. Yellow-bellied toads grew rapidly in early life; thereafter their growth was very limited. Body size was not an accurate age indicator of an individual of this species. The body length 51-55 mm was maximal in this locality. Yellow-bellied toads were long-lived in nature, some individuals surviving for much more than ten years, and perhaps even more than 20 years. The skeletochronological technique (counting the growth lines in phalangeal cross-sections of the clipped toes of some marked individuals) underestimated the actual age of these animals.

scholarly journals The ocellate river stingray (Potamotrygon motoro) exploits vortices of sediment to bury into the substrate

2019 ◽  
Author(s):  
S.G. Seamone ◽  
D.A. Syme
Keyword(s):  
Particle Image ◽  
Dorsal Surface ◽  
Ventral Surface ◽  
The Body ◽  
Effective Control ◽  
Posterior Portion ◽  
Dorsal Midline ◽  
Pectoral Fins ◽  
Image Velocimetry ◽  
Sediment Flow

ABSTRACTParticle image velocimetry and video analysis were employed to discern and describe the mechanism used by the stingray Potamotrygon motoro to bury into the substrate. P. motoro repeatedly and rapidly pumped the body up and down while folding the posterior portion of the pectoral fins up and over, drawing water in and suspending sediment beneath the pectoral disc. As the fins folded up and over, vortices of fluidized sediment travelled along the ventral surface of the fins toward the fin tips, and were then directed onto the dorsal surface of the fins and towards the dorsal midline of the fish, where they dissipated and the sediment settled over the dorsal surface of the ray. As displacement and speed of the body pumping and finbeat motions increased, the speed of the sediment translating across the dorsal surface increased, and accordingly, sediment coverage of the dorsal surface increased. Mean sediment coverage was 82.5% ± 3.0 S.E.M, and appeared to be selectively controlled, whereby the pectoral fins tended to bury more than the body, head and tail, and the body more than the head and the tail. In the most vigorous burying events, vortices of sediment shed from each fin collided at the midline and annihilated, reorienting the sediment flow and sending jets of sediment towards the head and the tail, covering these locations with sediment. Hence, this study demonstrates that the mechanism of burying employed by P. motoro permits effective control of sediment vortices and flows to modulate the extent of burying.

scholarly journals AN ANTS'-NEST COCCID FROM NEW MEXICO

1898 ◽  
Vol 30 (2) ◽  
pp. 47-48 ◽  
Author(s):  
J. B. Tinsley
Keyword(s):  
New Mexico ◽  
Dorsal Surface ◽  
Ventral Surface ◽  
The Body ◽  
Naked Eye ◽  
Average Size

Adult ♀.—Length, 5 mm.; width, 3 mm.; many are smaller than this, but this seems to be the average size of the adult containing eggs. Colour yellowish-gray, although they appear light gray, from the mealy secretion which covers the body.Shape, ellipsoidal, dorsal surface quite convex, ventral surface flat, extremities rather pointed. segmentation quite distinct to naked eye. Extremely short lateral appendages, little projections just visible; caudal appendages a little longer.

scholarly journals Correlations Between Body Angles and Substrate Curvature in the Parasitoid Wasp Trichogramma Minutum: A Possible Mechanism of Host Radius Measurement

1986 ◽  
Vol 125 (1) ◽  
pp. 271-285 ◽  
Author(s):  
J. M. Schmidt ◽  
J. J.B. Smith
Keyword(s):  
Parasitoid Wasp ◽  
Surface Curvature ◽  
The Body ◽  
Host Recognition ◽  
Host Acceptance ◽  
Body Parts ◽  
Trichogramma Minutum ◽  
Curvature Detection ◽  
Curvature Measurements ◽  
Different Diameters

The parasitoid wasps of the genus Trichogramma use the surface curvature of their insect egg hosts to set an upper limit to the number of progeny allocated to the host, as well as the duration of their host examination. In addition, host recognition and host acceptance are in part mediated by surface curvature. In this paper, the relationships between the positions of body parts of the wasp and surface curvature are examined in order to determine a possible mechanism for curvature detection by the wasp. Wasps of different sizes were photographed in profile while examining glass bead models of different diameters. The positions of selected body parts were analysed using a digitizer and microcomputer. The height of the wasp above the model surface did not change with surface curvature. Furthermore, the angle of the head relative to the thorax was also constant over the range of models used. Only the scapal-head angle and flagellar-head angle changed significantly with surface curvature. A curvature detecting mechanism is proposed in which the wasp uses the scapal-head angle to measure the curvature of the surface. The body of the wasp is maintained at a preferred height and angle to the substrate, serving as a fixed platform from which curvature measurements are made. Additional features of this mechanism, as well as its correlation with morphological and behavioural findings, are discussed.

Sensory Regulation of Wing Twisting in Locusts

1966 ◽  
Vol 44 (1) ◽  
pp. 1-16
Author(s):  
ERIK GETTRUP
Keyword(s):  
Hind Wing ◽  
Ventral Surface ◽  
The Body ◽  
Flight Period ◽  
Campaniform Sensilla ◽  
Motor Patterns ◽  
Body Angle ◽  
Central Processing ◽  
Sensory Regulation ◽  
Three Body

1. The campaniform sensilla of the wings are necessary for the regulation of wing twisting in locusts. Control of forewing twisting during periods of constant lift depends upon the hind-wing sensilla being intact, whereas the forewing sensilla are essential for stability about the three body axes. 2. The campaniform sensilla are located on the ventral surface of the wings. Two groups are present on the subcosta of the forewing and one on the subcosta of the hind-wing. A few single sensilla occur on the costa. The cuticular parts of sensilla from distal and proximal forewing groups differ with respect to the lengths of their ovally shaped cuticular parts. The sensilla are orientated with the cupolas parallel to the long axis of the wing, except for those of the proximal forewing group, which are arranged in a fan. 3. During steady-state flights activity from campaniform units was high during the downstroke and low during the first part of the upstroke. Significant changes in the response were found to occur when the body angle was changed. 4. The effect of a 15° change in body angle on the motor output to the basalar and subalar muscles is described. At the start of a flight these motor patterns are rather unstable, units falling in and out. Stability is gained within 10 sec. 5. A distinct part of the response from the campaniform units in the hindwings can be abolished by the application of an anodic block. The duration of the blocking pulse equalled one-sixth of the flight period. The effect on regulation of forewing twisting varied according to the part of the response which is removed. Regulation could be abolished almost completely when the anodic block was introduced during the first part of the hindwing downstroke. When the anodic block is removed, twist regulation builds up again and is completed within 100-150 wing-beats. 6. Free flights including both intact and deafferentated animals made possible an evaluation of the importance of the different groups in stability reactions. It was shown that control of angular movement is accomplished by the forewing groups only, especially the proximal ones. 7. The integrative processes within the pterothoracic ganglia are discussed. During the constant-lift reaction, the slow, intersegmental reflex for control of forewing twisting seems to depend on central processing and memorizing of measurements of total lift. The sensory input from the hindwings is phasic and patterned, but it is still undecided whether it is the phase or the pattern which is the essential parameter.

Gross morphological studies on the sternum of crested serpent eagle (Spilornis cheela)

2019 ◽  
Author(s):  
O.P. Choudhary ◽  
P.C. Kalita ◽  
T.K. Rajkhowa ◽  
R.S. Arya ◽  
A. Kalita ◽  
...  
Keyword(s):  
Morphological Characteristics ◽  
Dorsal Surface ◽  
Ventral Surface ◽  
The Body ◽  
Median Line ◽  
Lateral Border ◽  
Lateral Process ◽  
Morphological Studies ◽  
Quadrilateral Plate ◽  
Flat Bone

The present study was designed to elucidate the morphological characteristics of sternum of crested serpent eagle. The sternum was a thin, flat bone with a body, rostrum and keel. The body was quadrilateral plate with concave dorsal and convex ventral surfaces and four borders. Numerous pneumatic foramina were present on the dorsal surface. The ventral surface presented a large, boat shaped keel along its median line. The cranial border was convex and thick and two pneumatic foramina were present behind the cranial border on the ventral surface of sternum. The facets for coracoid bones were located just below the cranial border. The lateral border on either side presented six articular facets for sternal ribs. The triangular pointed cranio-lateral process was observed at the junction of cranial and lateral border on either side. The caudal border was convex and caudo-lateral processes were absent. Two distinct oval foramina were seen near the caudal border. The rostrum or sternal spine was smaller and located just below the cranial border of the body of the sternum. The sternum presented a well-developed triangular keel located along the midline of the ventral surface of the body of sternum.

scholarly journals Scanning electron microscopy on Gotocotyla acanthura (Monogenea, Gotocotylidae) from Pomatomus saltatrix (Ostheichthyes, Pomatomidae) in Brazil

2011 ◽  
Vol 20 (4) ◽  
pp. 342-346 ◽  
Author(s):  
Maria Clara Pamplona-Basilio ◽  
Helene Santos Barbosa ◽  
Simone Chinicz Cohen
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Genital Atrium ◽  
Posterior Extremity ◽  
Dorsal Surface ◽  
Ventral Surface ◽  
The Body ◽  
Pomatomus Saltatrix ◽  
Muscular Structure ◽  
Scanning Electron

Gotocotyla acanthura (Parona & Perugia, 1896) Meserve, 1938 collected from the gills of Pomatomus saltatrix from the coast of the state of Rio de Janeiro state was analyzed using scanning electron microscopy (SEM). The study demonstrated the presence of a buccal cavity, a genital atrium on the ventral surface and a muscular structure on the dorsal surface at the level of the body constriction. An elongated haptor with 80 to 120 pedunculated clamps symmetrically distributed in two rows, with rib-like thickenings and a curved lappet bearing a pair of hooks at the posterior extremity of the body were also observed. The cirrus could be seen protruding from the genital atrium, armed with pectinate spines along its length and presenting up to eight pointed spines around the genital atrium.

Observations on the behaviour of Thalassema thalassemum (echiura: echiuridae)

1994 ◽  
Vol 74 (4) ◽  
pp. 963-966
Author(s):  
L.A. Nickell ◽  
R.J.A. Atkinson
Keyword(s):  
Significant Contribution ◽  
Dorsal Surface ◽  
Ventral Surface ◽  
Distal Portion ◽  
Sediment Surface ◽  
Ciliary Movement ◽  
Faecal Pellets ◽  
Particle Collection ◽  
Closed Tube ◽  
Sediment Particles

The echiuran worm Thalassema thalassemum (Echiura: Echiuridae), is a deposit-feeder which uses its proboscis to collect sediment particles for ingestion. The proboscis is highly extensible and is used with dorsal surface downwards to skim particles from the sediment surface. Alternatively, the distal portion of the proboscis is arched over and the ventral surface of the tip is held against the sediment surface where ciliary movement facilitates particle collection. These methods are used in combination and collected material is moved back along the proboscis, the edges of which are rolled to form a closed tube. Burrows appear to be U-shaped with one predominantly inhalant and one exhalant opening. Faecal pellets are periodically ejected forming small mounds around exhalant openings and mean rates of 1·83 and 2·80 g dry wt d−1 were measured suggesting that, in sufficient densities, this species could make a significant contribution to macrofaunal bioturbation.

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