Gular Area Research Articles

Lubrication in the joints of insects (Arthropoda: Insecta)

AbstractFemoro‐tibial leg joint, head–prothorax joint (gular area) and occipital region of the head were examined using scanning electron microscopy in insects from the orders Blattodea and Coleoptera. Lubricating substances and corresponding pore openings were found in Argentinean Wood Roach Blaptica dubia and in the beetles from families Carabidae, Hydrophilidae, Silphidae, Scarabaeidae, Elateridae, Tenebrionidae and Curculionidae. Lubricant on the contacting surfaces were found on femoral and tibial counterparts of leg joints of different beetle species and cockroaches, in the gular region of the head in beetles, and in the occipital region of the head of the cockroach. Typical pore opening was on an average 1 µm in diameter (ranging from 0.5 µm to 10.0 µm). The amount of pore openings in a joint varies from a few pores to hundreds. The lubricant is found to be strongly variable in its appearance usually in the form of a single elongated filiform flow, as well as long or short drops, often forming accumulations or spreading over the surface. The supposed function of the lubricant in studied joints is discussed and assumed as friction and wear minimization. The presence of a high amount of the lubricant in leg joints of insects with intense leg locomotion is presumed.

A Noninvasive Electrophysiological Investigation of Tactile Sensitivity in Cyprinid Fish (Cyprinidae)

Tactile reception in cyprinid fish (silver crucian carp Carassius auratus gibelio and common carp Cyprinus carpio) was investigated by noninvasive recording of action potentials from the head skin in response to rhythmic tactile stimulation. Responses shaped as electric potentials following synchronously with changes in the pressure force on the skin were recorded using chloro-silver electrodes. It was shown that fish, like all terrestrial vertebrates, have phasic and tonic tactile receptors. Three main types of tactile responses were distinguished: (1) tonic responses as potential fluctuations repeating the dynamics of the tactile stimulus, (2) phasic responses as on-, off-, and on-off potentials, and (3) slow deflections from the resting potential. Compound responses comprising simultaneously different types of responses were also recorded. The response latency averaging 6.1 ms for tonic and 4.4 ms for phasic responses was clearly independent of the stimulus direction (switch-on, switch-off). The threshold level of tactile sensitivity in the perioral and gular head areas was 0.05–0.2 g/mm2. Tactile receptors on the silver crucian carp and common carp heads exhibited zonal distribution patterns, with sensory areas differing in their tactile sensitivity. Most sensitive areas were on the upper and lower lips, in the perilabial skin and the gular area on the ventral side of the head. Less sensitive areas were situated rostrally and ventrally to the eyeball. The areas situated dorsally and caudally to the eyeball proved to be insensitive to the applied tactile stimulation. In all sensory areas on the fish head, most intense responses were evoked by sliding tactile stimuli. The distribution specificity of tactile sensory areas meets their functional significance for fish feeding behavior.

A New Calotes Species from Sri Lanka with a Redescription of Calotes liolepis Boulenger, 1885

Abstract: Based on morphological evidence, we describe a new species of agamid lizard of the genus Calotes that is restricted to a single site on the northern face of the Knuckles massif (∼1000 m above sea level) of Sri Lanka. The genus Calotes consists of eight species in Sri Lanka, six of which appear to form an endemic radiation. The new species, Calotes manamendrai, most closely resembles Calotes liolepis Boulenger, 1885, which is widely distributed in mid-elevations in the central highlands, lowland rain forests, and a few isolated moist forests in the dry zone of Sri Lanka. Females of Calotes manamendrai sp. nov. differ from the females of Calotes liolepis in having nonenlarged pectoral scales; keeled dorsal scales on the body; smaller midgular scales than the rest of the throat scales; brown color, seven distinct stripes each side on gular area; black color shoulder pit; and upper arm with carinate ventral scales. Finally, we provide a complete redescription for Calotes liolepis based on the adult...

Hargreaves does not evaluate nociception following a surgical laparotomy in Xenopus leavis frogs

The present study was performed to determine the effectiveness of the Hargreaves test for the evaluation of nociception in frogs, more precisely to determine if cutaneous thresholds to a radiant heat stimulus would increase with analgesics following an abdominal laparotomy performed under general anaesthesia. Non breeding female Xenopus leavis frogs (3 groups (non-anaesthetized, anaesthetized with tricaine methanesulfonate (MS222), with or without an abdominal laparotomy) were used to evaluate the effectiveness of the Hargreaves test. Cutaneous thresholds were evaluated at baseline and following anaesthetic recovery (over 8 h) at six different body locations. Increased reaction times were observed in the gular area only at 1 h post-recovery following a MS222 bath immersion in frogs with (p < 0.02) and without the abdominal laparotomy (p < 0.002). In conclusion, the Hargreaves test does not provide an adequate test to evaluate nociception induced by an abdominal laparotomy and consequently cannot be used to evaluate analgesics in X. leavis frogs.

Harttia absaberi, a new species of loricariid catfish (Siluriformes: Loricariidae: Loricariinae) from the upper rio Paraná basin, Brazil

A new species of Harttia, tribe Harttiini, is described from tributaries of upper portions of rio Paraná drainage. The new species, the smallest known species of the genus, attaining up to 74.0 mm of standard length, can be distinguished from its congeners by the combination of the following characters: abdomen completely covered by plates, a single preanal plate, plates of the gular area in broad contact with the canal plate. Harttia absaberi is the second species of the genus known from the upper portion of rio Paraná drainage.

A new species of Diporiphora from the Goneaway Tablelands of Western Queensland

Australia’s agamid genus Diporiphora is speciose and widespread, however, there remain significant taxonomicuncertainties within this group. Field collections across the range of Diporiphora continue to uncover undocumentedmorphological and ecological variation. A new morpho-type was collected from hard pebbly soils on Valetta Station,western Queensland, providing ample data for the description of a new species (Diporiphora ameliae sp. nov.). Weundertook a morphological study, integrated with a comprehensive genetic study to provide the phylogenetic placementand distinctiveness of the new species. Although superficially similar to Diporiphora winneckei, the new species ischaracterised by well developed ventral body patterns consisting of four longitudinal grey stripes on a cream backgroundand three distinctive dark V-shaped markings that converge anteriorly on the throat and gular area. Molecular data ispresented incorporating a ~1200 bp of the mtDNA protein-coding gene ND2 and five flanking tRNAs for 58 newsequences and 53 previously published sequences. Phylogenetic analyses of the molecular data strongly support the newspecies as an independent evolutionary lineage within Diporiphora. In addition, the molecular data also showed that thereis far greater diversity in Diporiphora winneckei sensu lato than was anticipated. Our results clearly indicate that there are at least three independent evolutionary lineages of D. winneckei-like dragons.

A strikingly polychromatic new species of Gonatodes (Squamata: Sphaerodactylidae) from northern Venezuela

We describe a new species of diurnal gecko, Gonatodes rozei sp. nov., from tropical and premontane humid forests ofnorth central Venezuela. The new species can be distinguished from other congeners by a combination of large size, sub-caudal pattern B (1’1’1’’), three or four lateral scale rows on the digits, males with blue iris, scalation of the gular area,and aspects of color pattern in males and females. The new species is strongly sexually dichromatic and up to four different color morphs are observed in males.

BILL IMPACTION IN A GROUP OF CAPTIVE CARIBBEAN FLAMINGOS (PHOENICOPTERUS RUBER RUBER)

Flamingos are filter feeders that only rarely ingest larger food items. Their bill anatomy is adapted to the suction, filtration, and ejection of a fluid medium. This case report documents a rare case of bill impaction in a group of Caribbean flamingos (Phoenicopterus ruber) that were kept in a mixed exhibit together with roseate spoonbills (Platalea ajaja) and scarlet ibis (Eudocimus ruber). The latter species received fatty minced meat as part of their diet, which was also accessible to the flamingos. Weakness and poor body condition of one flamingo were noted. On clinical examination, the animal was emaciated, hypoglycemic, and showed a severe impaction of the bill with a mixture of lard, mud, and sand. This mixture had compressed the tongue and eventually had most likely prevented further food intake. In five additional flamingos, a bulging of the gular area, similar to the extension of this area during the tongue-retraction stage of the feeding cycle, was noted and interpreted as a sign of tongue displacement by similar masses in their bills. All animals were caught and the masses removed. All animals resumed food intake immediately, and the emaciated animal rapidly improved in condition. Food presentation was changed so that the trays for the other species were no longer accessible to the flamingos, and no similar problems have been observed since that time.

DETECTION OF BATRACHOCHYTRIUM DENDROBATIDIS IN ELEUTHERODACTYLUS FITZINGERI: EFFECTS OF SKIN SAMPLE LOCATION AND HISTOLOGIC STAIN

Batrachochytrium dendrobatidis is a fungal pathogen that has been implicated in amphibian declines worldwide. Histopathologic techniques have been used to diagnose the disease, but their sensitivity has not been determined. It is also unclear whether the probability of detection varies between skin samples derived from different body parts. We examined 24 Fitzinger's rainfrogs (Eleutherodactylus fitzingeri) with chytridiomycosis. This is a common frog species with a broad range and high abundance throughout most of Costa Rica. We sampled 12 different body parts from each animal, and alternated the staining between a routinely used stain (hematoxylin and eosin [H&E]), and a more fungus-specific stain (periodic acid-Schiff [PAS]). The pelvic patch and the innermost finger of the hand were consistently the best places to detect the disease, although significant differences were found only with the gular area, the abdomen, and toes four and five. We found more positive samples using PAS than using H and E in all body parts, although significant differences were detected only in samples derived from the pelvic patch. Using the best combination of factors (stain and body part) and animals with the lightest infections (to test the sensitivity of the technique), we calculated that at least 17 sections are needed in order to reach 95% confidence that a frog is or is not infected. We conclude that the choice of stain and body part can significantly alter estimates of prevalence of B. dendrobatidis.

Sex and population variation in ultraviolet reflectance of colour patches in Gallotia galloti (Fam. Lacertidae) from Tenerife (Canary Islands)

AbstractSex and population differences in the ultraviolet (UV) reflectance patterns of two phenotypically divergent lacertids from Tenerife, Gallotia galloti eisentrauti and G. g. galloti, are described. Adults in both populations have rows of lateral and ventro‐lateral blue patches on either side of the trunk that show a single peak of reflectance in the near UV. The lateral patches of males are more intensely reflective than those of females, but females have more chromatic and UV‐shifted lateral patches than males. Most G. g. eisentrauti and some G. g. galloti also have blue cheek patches on either side of the gular area. Male cheek patches have reflectance peaks in the near UV, whereas those of females peak in the visible part of the spectrum. The lateral patches of males from the two populations differ in hue but not in intensity, those of G. g. galloti being more UV‐shifted than those of G. g. eisentrauti. Female G. g. galloti have more intensely reflective lateral patches than female G. g. eisentrauti. Interindividual variation in peak wavelength and/or UV chroma is present in both sexes and populations. This is the first demonstration of sexual dichromatism in the UV reflectance of colour patches in a lacertid.

Host-parasite interactions between the piranha Pygocentrus nattereri (Characiformes: Characidae) and isopods and branchiurans (Crustacea) in the rio Araguaia basin, Brazil

In the tropics, studies on the ecology of host-parasite interactions are incipient and generally related to taxonomic aspects. The main objective of the present work was to analyze ecological aspects and identify the metazoan fauna of ectoparasites that infest the piranha, Pygocentrus nattereri. In May 2002, field samples were collected in the rio Araguaia basin, State of Goiás (Brazil). A total of 252 individuals of P. nattereri were caught with fishhooks and 32.14% were infested with ectoparasite crustaceans. The recorded ectoparasites were branchiurans, Argulus sp. and Dolops carvalhoi and the isopods Braga patagonica, Anphira branchialis and Asotana sp. The prevalence and mean intensity of branchiurans (16.6% and 1.5, respectively) and isopods (15.5% and 1.0, respectively) were similar. Isopods were observed in the gills of the host; branchiurans were more frequent where the skin was thinner, and facilitated attachment and feeding. The ventral area, the base of the pectoral fin and the gular area were the most infested areas. The correlations between the standard length of the host and the variables intensity and prevalence of crustaceans parasitism, were significant only for branchiurans (rs = 0.2397, p = 0.0001; chi2 = 7.97; C = 0.19). These results suggest that both feeding sites and body size probably play an important role in the distribution and abundance of ectoparasites.

A new species of saw‐scaled viper of the Echis coloratus complex (Ophidia: Viperidae) from Oman, Eastern Arabia

A study of 353 museum specimens of the Echis coloratus complex from its entire range of distribution revealed an undescribed species in the United Arab Emirates and northern Oman. The results of UPGMA clustering and principal coordinate analysis of 138 male and 142 female specimens yielded for both sexes two major clusters, one with specimens from the UAE and northern Oman and one from southern and western Arabia, the Levant and Egypt. The new species has a longer tail with higher subcaudal counts; the lower prenasal scale is often missing and the upper prenasal is frequently fused with the nasal; the subnasal is often missing or fused with the nasal. The gular scales between the chin‐shield and the preventrals are round or only slightly elongate, not elongate as in Echis coloratus, and their number is higher. Other differences in characters of the gular area indicate a different scale structure of the ventral surface of the head. The new species is allopatric or parapatric with E. coloratus, but sympatric with Echis carinatus sochureki.

Sound radiation and postglottal filtering in frogs

This work presents a comparison across selected species of several aspects of the mechanism of sound radiation in frogs. Measurements of the magnitude of the transfer function of the radiating structures show that the structures radiating the bulk of the energy present in the call vary depending on the species. Bullfrogs (Rana catesbeiana) radiate most of the energy (89% sound level) in their calls through their eardrums. Additionally, the transfer function of the eardrums displays peaks coincident with those observed in the mating and release call of this species. The vocal sac and gular area contribute energy only in the lower band (150–400 Hz). The ears are responsible for radiating additional frequency bands to the ones radiated through the vocal sacs. In Rana pipiens, the ears also broadcast a significant portion of the energy present in the call (63% sound level), but the frequencies of the aural emissions are a subset of those frequencies radiated through the vocal sacs. Finally, the barking treefrog (Hyla gratiosa) appears to use two different structures to radiate his call. The low-frequency band is preferentially radiated through the lungs while the high-frequency components are radiated through the vocal sac.

Patterns of Panting and Gular Flutter in Cormorants, Pelicans, Owls, and Doves

Most birds pant when subjected to heat stress, but some supplement evaporation from the respiratory tract by fluttering the gular area. Gular flutter occurs in at least the following taxa: cormorants, pelicans, boobies, anhingas, frigate-birds, herons, owls, doves, roadrunners, colies, and many gallinaceous species. The mechanics of gular flutter have been examined only in the Poor-will, Phalaenoptilus nuttallii (Lasiewski and Bartholomew 1966), but data on rates of gular flutter are available for a number of species, including the Common Nighthawk, Chordeiles minor (Lasiewski and Dawson 1964), Domestic Pigeon (Columba livia (Calder and Schmidt-Nielsen 1966), Bobwhite (Colinus virginianus), Gambel's and California Quail (Lophortyx gambelii and L. californicus), Painted Quail, Excalfactoria chinensis, Screech Owl, Otus asio, and Mourning Dove, Zenaidura macroura (Lasiewski et al. 1966b). The ability of birds that employ gular flutter to dissipate all of their metabolic heat through evaporation has been demonstrated in the Poor-will (Bartholomew et al. 1962), Common Nighthawk (Lasiewski and Dawson 1964), Domestic Pigeon (Calder and Schmidt-Nielsen 1966), Inca Dove, Scardafella inca (MacMillen and Trost 1967), and the Painted Quail (Lasiewski et al. 1966a). In caprimulgids the rate of flutter is independent of heat load and appears to be determined by the resonant properties of the gular area, just as the panting rate of dogs is determined by the resonant properties of the thoraco-abdominal region (Crawford 1962). The present study was undertaken to examine aspects of gular flutter and breathing in several birds of widely differing morphology and behavior. Through the cooperation of the staff of the San Diego Zoological Gardens, we were able to make measurements on a Double-crested Cormorant (Phalacrocorax auritus), a Brown Pelican (Pelecanus occidentalis), a Homed Owl (Bubo virginianus), and a Barn Owl (Tyto alba). Mourning doves (Zenaidura macroura) and a Horned Owl were studied on the Los Angeles Campus of the University of California.

Evaporative water loss in birds—II. A modified method for determination by direct weighing

1. 1. A direct weighing method of determining avian evaporative water loss under conditions of controlled temperature and humidity was developed. 2. 2. Ambient water vapor pressure and evaporative water loss are inversely related in Excalfactoria chinensis at 32,25 and 15°C. 3. 3. Evaporative water loss at a given temperature in E. chinesis is proportional to the water lossa vapor pressure gradient between the environment and evaporative surfaces. 4. 4. Maximum rates of gular flutter in a variety of species are roughly inversely related to the size of the gular area. 5. 5. Panting and gular fluttering may occur at rates determined by the resonant characteristics of thoratic cavity and gular region, respectively, or at apparent nonresonant frequencies.

Observations on Laying, Development, and Hatching of the Eggs of Batrachoseps wrighti

N April 1, 1948, an adult female Batrachoseps (=Plethopsis) wrighti, heavily laden with eggs, was obtained at the type locality, 8.7 miles southeast of Sandy, Clackamas County, Oregon. Since the eggs of this salamander were unknown, she was brought into the laboratory in the hope that oviposition could be observed. She was placed in a gallon glass container with a metal screw lid. A single paper towel, wetted with distilled water, was put into the bottom of the jar. The container with the salamander was kept in a dark room where the temperature was maintained continuously at approximately 12? C. Thermal data on field animals suggested that this temperature might be commonly experienced under natural conditions. After nearly one month in captivity, the salamander still retained her eggs. Dispairing of obtaining them without stimulation, I employed the pituitary implantation technique described by Noble and Richards (1930) and thereby oviposition was initiated. Implantation was done as follows. On May 25, 1948, at 3:40 P.M., I implanted a single whole pituitary gland freshly removed from an adult male Hyla regilla. The salamander was anesthetized in chlorotone (1 part saturated solution to 3 parts water), whereupon a small incision was made in the skin of the gular area. The Hyla pituitary was removed with forceps and was transferred directly to the site of the incision. A dissecting needle was used to force the gland into place beneath the the skin. By the time the salamander recovered from the chlorotone, several hours later, coagulation of blood and lymph at the site of the operation prevented displacement of the implant. About 42 hours later, a second Hyla pituitary was implanted. On June 1, 1948, at 9:00 A.M. the first egg was laid. Laying was completed June 2 at around 9:00 P.M., approximately 36 hours after the beginning of oviposition. Eleven eggs were deposited. Their chronology was as follows: June 1-3 eggs laid at approximately 21/2 hour intervals, around 9:00 A.M., 11:30 A.M., and 2:00 P.M.; June 2-8:40 A.M., 7 eggs present with the 8th emerging; 1:30 P.M., 9th egg emerging; 7:15 P.M., 10 eggs; 9:00 P.M., 11 eggs. The brief description of the eggs (Stebbins and Lowe, 1949), may now be supplemented [see Fig. 1, (1)]. The most striking characteristic of the eggs is their size. After some hours on the wet paper towel of the container, the jelly layers had swelled enormously, measuring, to their outer surfaces, 9 to 10 mm. The female salamander, only about 5 mm. in greatest width, seemed incredibly small to have deposited such large eggs (see Fig. 2, A). When laid, the jelly layers were thin and the vitellus was elastic, permitting its passage, with some temporary distortion, through the cloacal aperture. The vitellus, or egg proper, was unpigmented, between Cream Color and Pale Ochraceous-Buff.1 It rotated with the animal pole uppermost when the egg

THE MORPHOLOGY OF THE HEAD-CAPSULE OF SOME COLEOPTEROUS LARVAE

A comparative study of the external morphology of 46 species of the more common coleopterous larvae. The antennae and ocelli exhibit wide variation. From the fronto-dorsal aspect, the generalized structure of the head is shown, with which may be compared the modifications which occur and which lead to the disappearance of all the sutures separating the different areas found in this region. From the postero-ventral aspect, the heads are divided into two distinct groups, those that possess a gular area and those that do not. Here again, the specialization is compared with the generalized condition. Where a gula occurs, its development is first traced through the series, and then its gradual suppression, due to specialization, is illustrated. The disappearance of sutures causes the head-capsule to become very compact and heavily sclerotized, and this condition is found to be more general and complete in the campodeiform type of larvae.