bluuebunny/crossref_metadata_2025_split huggingface dataset:
Oxidative activity of poikilotherm mitochondria as a function of temperature
Authors: Newell R. C. 
Published: August 2009

In Newell & Northcroft (1967) evidence was presented which showed that the metabolism of certain intertidal invertebrates at rest does not vary greatly with temperature change. The following work was undertaken to determine whether temperature‐independent metabolism could be demonstrated in suspensions of mitochondria extracted from poikilotherm tissue and whether it could be inferred that there was any difference in the ability of poikilotherms from different habitats to adjust to short‐term temperature change.It was found that the rate of reaction/temperature curve of mitochondria isolated from the skate Raia had a flattened region below 10d̀C but above this the rate of oxidation of succinate and pyruvate increased regularly with temperature. The curve for intertidal forms had a gradual slope extending as high as 20d̀C in the mussel Mytilus edulis while in the terrestrial snail Helix aspersa the gradual slope reached 27.5d̀C after which the rate of oxidation of substrate increased sharply before declining towards higher temperatures. Finally, the curve for mitochondria isolated from the desert locust Schistocerca gregaria showed a gradual slope up to 35d̀C after which a sharp increase in the rate of oxidation of substrate occurred. Thus the extent of the gradual slope corresponds with the normal environmental temperature range to which the tissues of the poikilotherms are subjected and the general form of the R‐T curve is such that rapid fluctuations within the normal environmental temperature range have relatively little effect on the rate of mitochondrial activity.
The systematics of the genus Lates (Teleosti: Centropomidae) in Lake Albert, East Africa
Authors: Holden M. J. 
Published: August 2009

The systematics of thc genus Lares Cuvier, 1828 in Lake Albert were examined. It is concluded that the inshore form, originally described as Lates albertianus Worthington, 1929 and subsequently as L. niloticus albertianus should be considered as a synonym of L. niloticus (Linné, 1762) but that the offshore form, Lates macrophthalmus Worthington, 1929, warrants full systematic status. It had been relegated to subspecific status, L. niloticus macrophthalmus.The lectotype for L. macrophthalmus is selected and redescribed. A method by which the species could have evolved, based on suspected differences in partial pressures of oxygen at which the blood haemoglobins of the two species become saturated, and on desiccation of the lake in the Pleistocene period, is described.The diagnostic value of allometry in distinguishing between the two species on a morphological basis is discussed, as is the distribution of the two species in Lake Albert.The possible significance of interspecific differences in the shape of the caudal peduncle and caudal fin is considered.
Sisor rabdophorus—A study in adaptation and natural relationship: II. The interrelationship of the gas bladder, Weberian apparatus, and membranous labyrinth
Authors: Mahajan C. L. 
Published: August 2009

A detailed description of the gas bladder, the Weberian apparatus and the membranous labyrinth in Sisor rabdophorus is given. It has been shown that these structures show a number of specializations which can be correlated with the bottom‐living habits of the fish. Evidence has been brought forth to show that the Weberian mechanism continues to serve as an aid to hearing.It has been concluded that Günther's inclusion of Sisor in the group Hypostomatina along with certain loricariid and callichthyid genera is not a natural one and that Regan's (1911) and Berg's (1940) family Sisoridae is more indicative of natural relationships. That Sisor diverged early from the main stem of sisorid evolution, is further supported by this study.
Aspidomorphus, a genus of New Guinea snakes of the Family Elapidae, with notes on related genera
Authors: McDowell S. B. , Cogger H. G. 
Published: August 2009

The Australian snakes that have been included in Aspidomorphus differ markedly from that genus, particularly in hemipenial morphology and in the absence of a muscular slip from the quadrate bone to the venom gland; the genus Aspidomorphus is therefore restricted to the New Guniea species. Aspidomorphus (as here restricted) is closely related to Demansia (in the restricted sense of Worrell, essentially D. psammophis, D. torquata, and D. olivacea), but the Australian species generally referred to Aspidomorphus seem to be related to Glyphodon. The genera Aspidomorphus, Demansia, Rhinhoplocephalus and Drepanodontis form a natural group. Aspidomorphus contains three species, each identifiable by hemipenial features as well as by details of colouration: A. muelleri (=A. mülleri mülleri and A. m. interruptus of Brongersma's revision); A. lineaticollis (=A. mülleri lineaticollis and A. m. lineatus of Brongersma); and A. schlegeli. The last species differs from the others in the form of the maxillary bone and the anterior mandibular dentition; it seems to be confined to northwestern New Guinea and adjacent islands, since specimens from the eastern end of New Guinea that had been referred to schlegeli are actually A. lineaticollis. In all three species some geographical variation can be demonstrated, at least in ventral count, but it is not considered necessary to use trinomials to indicate that geographical variation exists. Pseudonaja textilis is recorded from New Guinea for the first time. (McDowell.)Examination reveals Demansia ornaticeps is properly referred to Demansia. (Cogger.)
Observations on the fluorescence and function of spiders' eyes
Authors: Young* M. R. , Wanless* F. 
Published: August 2009

Preliminary observations on spiders' eyes showed that certain eyes fluoresce in ultraviolet light and others do not. The response of these eyes to ultraviolet and visible light has been investigated to discover the relationship, if any, of eye fluorescence with eye function.In the first part of this paper it is shown that of eight spiders from families with widely differing habits, vision and behaviour, five species reacted to light fluctuations and to differences in brightness of the primary colours blue, green and red. Three species did not respond to lightand only two, S. scenicus and E. falcata, indicated a preference for blue light. It was also found that the visual sensitivity of S. secenicus extended into the ultraviolet. The second part of the paper gives the results of examination in ultraviolet light of the eyes of 40 species from 11 families. Spiders with poor sight and a preference for shade generally showed a strong fluorescence of all eyes. The anterior median and lateral eyes of those species with good sight fluoresced only weakly or not at all, whereas the posterior median and lateral eyes ofthese spiders fluoresced brightly.Freshly cut frozen sections of the eyes of two selected species, S. scenicus with good sight and C. similis with poor sight, were examined with the fluorescence, phase and polarizing microscopes. The localization of the fluorescence in these eyes is described and a fluorescent substance, common to all the spiders, was found in the lens of the eyes of most species examined.Additional information on the structure of the cornea and lens was also revealed by phase and polarized light microscopy.The results suggest that spiders' eyes respond to light in different ways and the fluorescent substance present in the lens of the eyes is related to eye function.
Interspecific differences in photosensitivity between three closely related species of pigeons
Authors: Lofts B. , Murton R. K. , Westwood N. J. 
Published: August 2009

It is known from field observations that vernal gonad recrudescence begins in January for the Stock dove, a month later at the end of February for the Wood pigeon, while many town pigeons (Columba livia) have active gonads throughout the year.Photostimulation experiments demonstrate that spermatogenesis can be stimulated in the Stock dove by exposure to an artificial daylength regimeincreasing from 9.1 to 10.8 hours over 28 days. This photoperiod is the approximate equivalent of natural daylength changes occurring from late January onwards at 52° N. The same phototreatment, however, was not stimulatory for the testes of Wood pigeons, which required the equivalent of a March photoperiod. Natural daylength changes occurring in late November and December failed to evoke gametogenetic recovery in Stock dove controls.The gonads of feral pigeons in full breeding condition were unaffected when the subjects were transferred from full summer photoperiods to those found in midwinter and spermatogenesis was maintained in birds kept under winter daylengths for four months.The discussion mentions the problem of intraspecific geographical variation in photosensitivity. Scottish Wood pigeons begin their gonad recovery earlier and by March have considerably larger testes than birds in the south of England. Furthermore, they achieve this more advanced condition before the vernal equinox when daylengths are shorter in Scotland than in the south of England.
The functions and mechanisms of the protrusible upper jaws of some acanthopterygian fish
Authors: Alexander R. McN. 
Published: August 2009

Photographs of Pterophyllum and Gasterosteus feeding indicate that they suck food into their mouths by expansion of the buccal and opercular cavities. The premaxillae are protruded as the mouth opens, and remain protruded as it closes. The mechanisms whereby these movements can be performed, by these and by more generalized acanthopterygians, are described. It is shown that the palatines of generalized acanthopterygians are so arranged as to prevent retraction of the premaxillae when the mouth is closed with the buccal cavity expanded.It is estimated, from rough measurements on a few species, that a teleost cannot suck into its mouth food that is further from its mouth opening than about one‐quarter of the length of its head. It is shown that protrusion of the premaxillae can be useful in getting the mouth opening close to food that is to be sucked in, expecially when it is to be taken from the bottom. The possible advantages of closing the mouth with the premaxillae protruded are discussed.The origin of the acanthopterygian protrusile mechanism is discussed.
Trend‐surface analysis of transformation grids
Authors: Sneath P. H. A. 
Published: August 2009

Computer methods are described for trend‐surface analysis of D'Arcy Thompson transformation grids, illustrated by data on skulls and jaws of hominoids.In comparing two diagrams the following steps are required. First, corresponding points on each diagram are marked, and their co‐ordinates are recorded. Second, the diagrams are scaled and fitted to give the best possible fit; this gives measures of size and shape difference. Third, the displacements of each point relative to its partner on the other diagram are subjected to trend‐surface analysis. The displacements are analysed in terms of linear, quadratic, cubic and higher order trends. Fourth, the differences based on the trends alone can now be estimated.The results on the illustrative examples are discussed, together with the difficulties in applying such methods. The nature of taxonomic (phenetic) affinity is also discussed, with suggestionsfor measuring different components of this concept.The techniques show promise for a wide variety of taxonomic and morphological applications.
Seasonal fluctuations in the protozoan parasites of the centipedes Lithobius variegatusand Lithobius forficatus in a Yorkshire woodland
Authors: Lewis J. G. E. 
Published: August 2009

The seasonal variation in percentage parasitization and in the average number of individuals of Echinomera spp. in Lithobius forficatus and L. variegatus is described and discussed. It is suggested that infection by Echinomera hispida may account for the low numbers of L.forficatus in damp woodlands.Coccidia occur only in L. variegatusand the incidence of metazoan parasites is very low.
Carotenoids and carotenoid metabolism in Carcinus maenas (Crustacea: Decapoda)
Authors: Gilchrist Barbara M. , Lee* W. L. 
Published: August 2009

The carotenoid pigments of the hepatopancreas, ovaries and epidermis of Carcinus maenas were investigated. The following pigments were identified: β‐carotene, δ‐carotene, echinenone, isocryptoxanthin, canthaxanthin, lutein, zeaxanthin, flavoxanthin and astacene.The relative abundance of these pigments in the three tissues and the presence of possible hydroxy and keto intermediates suggest the metabolism of astaxanthin from β‐carotene. The metabolic pathway in Carcinus is discussed in relation to recent studies on other invertebrates.
Oxidative activity of poikilotherm mitochondria as a function of temperature
Authors: Newell R. C. 
Published: August 2009

In Newell & Northcroft (1967) evidence was presented which showed that the metabolism of certain intertidal invertebrates at rest does not vary greatly with temperature change. The following work was undertaken to determine whether temperature‐independent metabolism could be demonstrated in suspensions of mitochondria extracted from poikilotherm tissue and whether it could be inferred that there was any difference in the ability of poikilotherms from different habitats to adjust toshort‐term temperature change.It was found that the rate of reaction/temperature curve of mitochondria isolated from the skate Raia had a flattened region below 10°C but above this the rate of oxidation of succinate and pyruvate increased regularly with temperature. The curve for intertidal forms had a gradual slope extending as high as 20°C in the mussel Mytilus edulis while in the terrestrial snail Helix aspersa the gradual slope reached 27.5°C after which the rate of oxidation of substrate increased sharply before declining towards higher temperatures. Finally, the curve for mitochondria isolated from the desert locust Schistocerca gregaria showed a gradual slope up to 35°C after which a sharp increase in the rate of oxidation of substrate occurred. Thus the extent of the gradual slope corresponds with the normal environmental temperature range to which the tissues of the poikilotherms are subjected and the general form of the R‐T curve is such that rapid fluctuations within the normal environmental temperature range have relatively little effect on the rate of mitochondrial activity.
“Necking” behaviour in the giraffe
Authors: Coe Malcolm J. 
Published: August 2009

Previous references to “necking” behaviour, and the main features of the study area are briefly outlined.“Necking” behaviour in giraffe takes place only in all male herds. When the animals are in a head to head posture the intensity is either high or low, but when animals take up a head to tail posture the actions are always of high intensity and appear to have greater sexual significance.The significance of “necking” is discussed, and it is suggested that these ritualized actions form an important sexuo‐social bonding mechanism whereby a hierarchy is created amongst the males,and movement between strictly bachelor and mixed herds helps to maintain contact between the sexesin this polygamous mammal.
Distribution of the plerocercoid of Ligula intestinalis
Authors: Orr T. S. C. 
Published: August 2009

The geographical distribution of the cestode Ligula intestinalis (Linnaeus 1758) is described with reference to the species of freshwater fish infected. Recent references indicate that the larval stage of this cestode is commonly reported from the Northern Hemisphere but less commonly from the Southern Hemisphere.Cyprinid fish are infected in the Northern Hemisphere in the New and Old World, and where cyprinid fish are scarce, fish occupying a similar ecological position are infected. However, the infection of Yellow perch in North America and the absence of infected European perch may suggest that the form in the Yellow perch if not morphologically, may be physiologically, distinct.In the Southern Hemisphere cyprinids have been reported as infected in Rhodesia and galaxids as infected in Australia. The infection of galaxids, some of which enter the sea to breed may indicate a possible method of distribution. It is suggested that transplantation of the larval cestode from the body cavity of one fish to another may yield more definite information as regards specificity.The infection of fish, other than those listed, is reviewed with reference to those fish known to occur in habitats where fish infected with Ligula intestinalis also exist.
On the age and growth of the freshwater eel (Anguilla anguilla)
Authors: Sinha V. R. P. , Jones J. W. 
Published: August 2009

The growth of over a 1000 eels from three different watersheds was investigated. Because of the difficulties of sexing eels we were only able to compare the size of females with that of eels with lobulate organs (some of the latter are potential females). Generally female eels grow faster than the others. There was little difference in the growth of eels with lobulate organs even though there was a great difference in the eel population density in the three localities. But, in any one locality there was a large range of growth. It is suggested that the competition for food is most acute amongst the smaller size groups. As they grow, eels tend to become cannibalistic and find small eels and elvers an easy source of food.The growth of some continental eels has been related to temperature but this is not confirmed by experimental work. Nevertheless eels eat little or nothing at low temperature as is shown by the large percentage of eels with empty stomachs in our samples.
On the food of the freshwater eels and their feeding relationship with the salmonids
Authors: Sinha V. R. P. , Jones J. W. 
Published: August 2009

Following the results of the cursory investigations made by Jones & Evans (1960,1962) into the predatory habits of eels we decided to enlarge on this work. Consequently we looked at the stomach contents of about 5000 eels. In addition and at the same time two Welsh streams carrying salmonids were selected and sampled specifically to try to determine the relationship in the feeding habits of eels and salmonids.The food of eels consisted mainly of trichopteran and dipteran larvae and plecopteran and ephemeropteran nymphs, though at times Gastropoda, Annelida, Crustacea and fish were common in the stomachs. Fish was not an important dietary item but, when eaten, the fish most commonly taken were elvers and eels.In the River Dwyfach the salmonids ate more or less the same type of food as the eels, but the trout ate more surface food than the young salmon.The similarity in feeding between the eels and salmonids resulted in apparent competition during the warmer months. In winter when the eels ate little the competition was thus almost negligible. Even though we speak of competition for the food available in the summer months we feel that before this can be accepted as fact we must know the relative abundance of each food organism eaten at this time.
The African elephant, Loxodonta africana: a field method for the estimation of age
Authors: Sikes Sylvia K. 
Published: August 2009

A new field method, now termed the “FM technique”, for age estimation in wild African elephants was outlined in a previous paper (Sikes, 1966a). In this technique, the stage reached in the molar progression which occurs throughout the life of any elephant, is related to a fixed point, namely the foramen mentale, in the lower jaw. The stage reached in any individual elephant of either sex may thus be described as its “molar age” by the “FM formula” (a descriptive, non‐mathematical formula). Up to the age of 30 years, molar age may be converted with reasonable accuracy to year age. Above this point, however, any such conversion must be regarded as arbitrary and of doubtful value until such time as adequate additional data from older African elephants of known age become available.The molars are briefly described, and the molar progression in the species outlined. A hypothesis is offered as a possible explanation of the mechanism of the progression. The field procedure for using the FM technique is explained, and its advantage over previous methods discussed. A comprehensive Age Reference Chart for field use is given, covering the whole potential life span of the African elephant.
Mobility and crystalline form of the lime in the cuticle of the shore crab, Carcinus maenas
Authors: Digby Peter S. B. 
Published: August 2009

Calcification of biological tissues is usually attributed to the operation of a template mechanism or to enzymes. An electrochemical mechanism has been proposed by the author to account for calcification in the shore crab, Carcinus maenas L. and elsewhere. In the crab, study of cuticle structure suggested that calcification may arise as precipitation of lime by an alkaline reaction resulting from diffusion processes, largely outward diffusion of salt. The mechanism is probably that salt diffusion produces a potential which results in a flow of hydrogen or hydroxyl ions through the liquid phase of the cuticle (membrane hydrolysis) or of electrons through semiconducting materials in the solid phase (producing electrode action at the two surfaces). The latter, electrochemical action, in which an alkaline reaction arises by cathodic action at the outer surface and acid by anodic at the inner, appears the more likely, although the conduction mechanism may be complex.Further evidence concerning the dependence of calcification on diffusion is now presented. The lime of the normal plaques in crab cuticle is shown to be mobile. Thus decrease of salinity on the outer side of the cuticle, which increases the normal salinity gradient across it, causes enhanced precipitation at or on the outer surface while increase of salinity on the outer side, which reduces or reverses the salinity gradient across it, causes reduced precipitation or solution at the surface and re‐deposition further in. These changes occur in similar ways in both non‐living preparations of cuticle and in living crabs and are attributed to changes in the positions of acid and alkaline layers by the direction of salt diffusion. Crabs kept out of water do not calcify. Lime precipitation in the cuticle is thus mainly controlled not by the nucleating properties of a specific organic template or by enzymes more or less fixed in position, but by salt diffusion. Further, crystalline deposits of lime very similar to those in the crab have been produced by precipitation of mixtures of the appropriate salts in a foreign material, cellophane. Inclusion of iron and magnesium is necessary to produce spherulites like those of the crab and even more similar forms can be produced in thin films of magnesium hydroxide gel. It is therefore not necessary to postulate any specific organic nucleating action for the production of such deposits in crab cuticle.
On the affinities of three fossil ocypodid crabs and their relevance to the time and place of origin of the genus Macrophthalmus (Crustacea: Brachyura)
Authors: Barnes R. S. K. 
Published: August 2009

All the species of Macrophthalmus described from fossil material belong to the still extant subgenus Venitus. M. vindobonensis and M. aquensis, the two earliest known species of the genus, are closely related to the extant M. latreillei, while M. guamensis is conspecific with M. leptophthalmus.Doubt is cast on Remy's (1952) theory of the late Tertiary migration of Macrophthalmus from the Mediterranean, its suggested place of origin, to the Indo‐West Pacific, its present distributional range. Instead it is proposed that Macrophthalmus arose in the Indo‐West Pacific during the late Eocene‐Oligocene, and extended its range into the Mediterranean during the early‐middle Miocene. The Mediterranean species became isolated during the late Miocene by a land bridge, and probably became extinct following the elevation of their brackish habitat during the late Miocene‐Pliocene.