scholarly journals AN ANTS'-NEST COCCID FROM NEW MEXICO

1898 ◽  
Vol 30 (2) ◽  
pp. 47-48 ◽  
Author(s):  
J. B. Tinsley

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.

2014 ◽  
Vol 88 (1) ◽  
pp. 68-91 ◽  
Author(s):  
Allison C. Daley ◽  
Gregory D. Edgecombe

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 All known specimens of A. canadensis, including previously unpublished material, were examined with the aim of providing a cohesive morphological description of this stem lineage arthropod.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.


2019 ◽  
Author(s):  
S.G. Seamone ◽  
D.A. Syme

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.


Author(s):  
O.P. Choudhary ◽  
P.C. Kalita ◽  
T.K. Rajkhowa ◽  
R.S. Arya ◽  
A. Kalita ◽  
...  

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.


2011 ◽  
Vol 20 (4) ◽  
pp. 342-346 ◽  
Author(s):  
Maria Clara Pamplona-Basilio ◽  
Helene Santos Barbosa ◽  
Simone Chinicz Cohen

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.


1962 ◽  
Vol 36 (1-2) ◽  
pp. 211-214
Author(s):  
S. Wahid

These trematodes were collected from the large intestine of a black-necked stork which had died in the Zoological Gardens, London. All the specimens present are damaged and there is only one piece showing the anterior part containing the head collar. It was not possible to determine the exact length of the specimens, but they are long and slender and measure at least 18 mm. in length. The body is almost uniform in width except in the regions of the ventral sucker and the testes where it is broader. The cuticle is thickly covered with spines in the anterior region of the body from the posterior border of the head collar to the posterior rim of the ventral sucker. On the dorsal surface the spines form a semicircle around the region of the ventral sucker and extend on either side of it. On the ventral surface very few spines are present on the sides of the sucker. The size of these spines varies a lot; in the anterior part they are very small, their size increasing towards the posterior region up to the end of the oesophagus from where it decreases again till the last row of spines which are very small.


1987 ◽  
Vol 232 (1268) ◽  
pp. 323-366 ◽  

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.


ZooKeys ◽  
2021 ◽  
Vol 1047 ◽  
pp. 27-60
Author(s):  
Tao Luo ◽  
Yali Wang ◽  
Siwei Wang ◽  
Xueli Lu ◽  
Weifeng Wang ◽  
...  

Herein, we describe Panophrys congjiangensissp. nov. obtained from the Yueliangshan Nature Reserve, Congjiang County, Guizhou Province, China. Phylogenetic analyses based on the mitochondrial genes 16S rRNA and COI indicated that this new species represented an independent lineage, closely related to P. leishanensis. The uncorrected genetic distances between the new species and its closest congener, P. leishanensis, were 3.0% for 16S rRNA and 8.4% for COI. The new species is distinguished from its congeners by a combination of the following morphological characteristics (1) medium body size (SVL 28.6–33.4 mm in males and 38.4–40.2 mm in females); (2) a small horn-like tubercle at the edge of each upper eyelid; (3) the tympanum distinctly visible (TD/ED ratio 0.47–0.66); (4) vomerine teeth absent; (5) the tongue not notched behind; (6) a narrow and unobvious lateral fringe on toes; (7) relative finger lengths II < I < V < III; (8) rudimentary webs on toes; (9) hindlimbs slender, heels overlapping when thighs are positioned at right angles to the body; (10) two metacarpal tubercles on the palm, with the inner metatarsal tubercle long and oval-shaped; (11) the tibiotarsal articulation reaching the nostril when the leg is adpressed and stretched forward; (12) dorsal skin rough with numerous orange–red granules, ventral surface smooth; (13) a single internal subgular vocal sac present in males; and (14) in breeding males, weak gray-black nuptial pads with black nuptial spines present on the dorsal surface of the bases of the first and second fingers. To date, the new species is only known from the type locality.


1937 ◽  
Vol s2-79 (316) ◽  
pp. 507-557
Author(s):  
DATUS M. HAMMOND

1. The neuromotor system of Euplotes patella Ehrenberg was studied in different stages of the life-cycle, including the adult, and asexual and sexual reproduction. 2. In the adult the basal granules of all the cirri are arranged in straight primary and secondary rows. The fibrils from the bases of the cirri are in general parallel with either the primary or secondary rows of basal granules of the cirri to which they are attached. This is interpreted as an indication of the evolution of the organism from an ancestor with a simple neuromotor system in which the cilia were uniformly distributed over the surface of the body in longitudinal, slightly spiral rows. 3. The basal apparatus of a bristle consists of a basal granule at the bottom of a depression in the ectoplasm which is surrounded by a group of rodlets and ends at the surface in a ring connected with the polygonal system. The polygonal or silverline system is pellicular in position. 4. During asexual reproduction the entire set of cirri is resorbed and replaced by two new sets of cirri, one for each daughter. One frontal cirrus for the anterior daughter develops in the old peristomial field of the parent, while the corresponding cirrus for the posterior daughter develops in the new peristome. The right marginal cirri arise on the dorsal surface along the rows of bristles and later move to the ventral surface. The fibrils develop outward from the bases of the cirri. 5. During binary fission a new peristome arises in a depression in the ectoplasm independently of the old peristome. The old peristome remains in the anterior daughter without at the time undergoing any visible change in structure. 6. The multiplication of the bristles is limited to a zone on either side of the future plane of constriction. Multiplication occurs by a series of fissions of the basal granules in this area. Dedifferentiation of bristles was not seen. 7. The polygonal system is replaced over the entire surface of the body with the exception of the old peristomial field. The new system originates in many separate loci in connexion with the bristles on the dorsal surface, and with the rudiments (Anlagen) of the cirri and peristome on the ventral surface. 8. During conjugation there are two successive reorganizations of the neuromotor system, that of the ‘gamete’ (conjugant) and that of the zygote. 9. The first reorganization, that of the gamete, begins during the maturation divisions preparatory to fertilization. During this reorganization the posterior portion of the peristome is resorbed and the remaining anterior portion is later replaced. The eighteen cirri are replaced by a set containing only seventeen cirri. 10. The second reorganization, that of the zygote, occurs during the differentiation of the nuclei in the exconjugants. It involves the completion of the peristome by differentiation of the missing posterior portion, and the replacement of the set of seventeen cirri by a complete set of eighteen cirri. 11. These protoplasmic reorganizations, invariably associated with both asexual and sexual reproduction, involve a structural and presumably a physiological rejuvenation resulting in the possibility of an indefinitely continued existence of the individual in the Protozoa. It may be that sexual reproduction is not necessary to bring about this result, but further work on the relationship of endomixis to the problem is needed.


Author(s):  
E. Ford

Growth in length during the transition from larva to adolescent in the pilchard and sprat has been analysed, and simple straight-line equations deduced from observed data have been used to demonstrate how the different intervals along the dorsal and ventral surfaces of the body alter in length and proportion as development proceeds.In the herring, pilchard, and sprat at least one of the body-intervals remains for all practical purposes unaltered in length during the transition. In the herring there are two such intervals, namely, (1) the distance from the back of the brain along the dorsal surface to the insertion of the first dorsal fin-ray, and (2) the distance from the insertion of the pelvic fins along the ventral surface to the anus. In the pilchard and sprat one of the above two remains stationary, but the other increases in length; in the pilchard the fixed interval is the distance from the back of the brain to the first dorsal fin-ray, and in the sprat it is the distance from the pelvics to the anus.In the herring and pilchard the greater part of each unit of increase in the length of the body ventrally from the back of the head to the end of the caudal peduncle is added in front of the pelvic fins, whereas in the sprat this is added post-anally.


2012 ◽  
Vol 4 (1) ◽  
pp. 52-53
Author(s):  
Bhargavi Srinivasulu ◽  
C. Srinivasulu ◽  
G. Chethan Kumar

The blue sea slug Glaucus atlanticus Forster, 1777 (Gastropoda, Glaucidae) is a nudibranch that occurs in temperate and tropical oceans throughout the world. It is characterized by a silvery white dorsal surface and dark blue ventral surface. The body is elongate measuring up to 3 cm and is flattened. The head is small and blunt with a pair of small oral tentacles near the mouth. The cerata or papillae are wing-like and extend laterally from three distinct pairs of peduncles. The papillae are placed in a single row (uniseriate) and may be 84 in total. A similar looking glaucid nudibranch, Glaucus marginata (Bergh, 1860), is a bluish-brown nudibranch with bluish underside, and differs from Glaucus atlanticus in bearing four pairs of clusters of papillae that are arranged in more than one row (multiseriate) and may be 139 or more in number. The latter species has been included by some authorities under the genus Glaucilla Bergh, 1860. Presently, both species are listed under Glaucus Poli, 1795.


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