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Speleology in Kazakhstan

Shakalov on 04 Jul, 2018
Hello everyone!   I pleased to invite you to the official site of Central Asian Karstic-Speleological commission ("Kaspeko")   There, we regularly publish reports about our expeditions, articles and reports on speleotopics, lecture course for instructors, photos etc. ...

New publications on hypogene speleogenesis

Klimchouk on 26 Mar, 2012
Dear Colleagues, This is to draw your attention to several recent publications added to KarstBase, relevant to hypogenic karst/speleogenesis: Corrosion of limestone tablets in sulfidic ground-water: measurements and speleogenetic implications Galdenzi,

The deepest terrestrial animal

Klimchouk on 23 Feb, 2012
A recent publication of Spanish researchers describes the biology of Krubera Cave, including the deepest terrestrial animal ever found: Jordana, Rafael; Baquero, Enrique; Reboleira, Sofía and Sendra, Alberto. ...

Caves - landscapes without light

akop on 05 Feb, 2012
Exhibition dedicated to caves is taking place in the Vienna Natural History Museum   The exhibition at the Natural History Museum presents the surprising variety of caves and cave formations such as stalactites and various crystals. ...

Did you know?

That aquifer stimulation is a type of development that is done in semiconsolidated and completely consolidated formations to alter the formation physically to improve its hydraulic properties [6].?

Checkout all 2699 terms in the KarstBase Glossary of Karst and Cave Terms

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Featured articles from Cave & Karst Science Journals
Chemistry and Karst, White, William B.
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Featured articles from other Geoscience Journals
Karst environment, Culver D.C.
Mushroom Speleothems: Stromatolites That Formed in the Absence of Phototrophs, Bontognali, Tomaso R.R.; D’Angeli Ilenia M.; Tisato, Nicola; Vasconcelos, Crisogono; Bernasconi, Stefano M.; Gonzales, Esteban R. G.; De Waele, Jo
Calculating flux to predict future cave radon concentrations, Rowberry, Matt; Marti, Xavi; Frontera, Carlos; Van De Wiel, Marco; Briestensky, Milos
Microbial mediation of complex subterranean mineral structures, Tirato, Nicola; Torriano, Stefano F.F;, Monteux, Sylvain; Sauro, Francesco; De Waele, Jo; Lavagna, Maria Luisa; D’Angeli, Ilenia Maria; Chailloux, Daniel; Renda, Michel; Eglinton, Timothy I.; Bontognali, Tomaso Renzo Rezio
Evidence of a plate-wide tectonic pressure pulse provided by extensometric monitoring in the Balkan Mountains (Bulgaria), Briestensky, Milos; Rowberry, Matt; Stemberk, Josef; Stefanov, Petar; Vozar, Jozef; Sebela, Stanka; Petro, Lubomir; Bella, Pavel; Gaal, Ludovit; Ormukov, Cholponbek;
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Your search for support (Keyword) returned 281 results for the whole karstbase:
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Origin of the sedimentary deposits of the Naracoorte Caves, South Australia, ,
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Forbes Ms, Bestland Ea,
The origin of the sediments located in the Naracoorte Caves (South Australia) was investigated via the analysis of strontium isotope ratios (87Sr/86Sr), elemental geochemistry, and mineralogy. Sedimentary deposits located in Robertson, Wet, Blanche and several other chambers in Victoria Cave are all variable mixes of fine sand and coarse silts, which display similar and consistent strontium isotope ratios (0.717-0.725). This suggests that over the 400[no-break space]ka time frame that these deposits span there has been minimal variation in the source of the clastic sediments. Increased strontium concentrations for these cave sediments correspond with increasing silt content, yet there is no correlation between 87Sr/86Sr ratios and silt content. This implies that the silt-sized component of the sediments is the main contributor of strontium to the cave sediments. Comparisons of 87Sr/86Sr with regional surficial deposits show a significant correlation between the cave sediments (avg: 0.7228; n = 27), the fine silt lunettes of the Bool Lagoon area (avg: 0.7224; n = 4), the sandy A horizons of the Coonawarra Red Brown Earths (RBEs; avg: 0.726; n = 5), and Holocene age podsolic sand deposits (0.723). These data suggest that there has been substantial flux from this group of deposits to the caves, as would be expected considering prevailing winds. This relationship is further supported by a strong correlation between many trace elements, including Ti, Zr, Ce, and Y; however, variations in clay mineralogy suggest that the fine silt-dominated lunettes and Padthaway RBEs were not significant contributors to the cave deposits. Hence, the detritus entering the caves was more than likely from areas proximal to the cave entrance and was dominated by medium grain-sized materials. Major regional deposits, including the coarser-grained, calcite-rich Bridgewater Formation sands, basalts from the lower SE, Padthaway Horst granites, Gambier limestone, and metamorphics from the Adelaide geosyncline show minimal correlation in 87Sr/86Sr ratios, elemental geochemistry, and mineralogy with the cave sediments, and are discounted as significant sources. In comparison, 87Sr/86Sr ratios for the Coorong silty sands (0.717-0.724), Lower Murray sands (0.727-0.730), and the medium size silt component of the Murray-Darling River system (0.71-0.72), compare favourably with the cave sediments. This relationship is further supported by similarities in elemental chemistry and mineralogy. Thus, much of the strontium-rich silt that is now located in the Naracoorte Cave sediments likely originated from the Murray-Darling basin. Over time, this material has been transported to the SE of South Australia, where it mixed with the medium sand component of the regressive dune ridge sequence, locally derived organic matter, limestone fragments, and fossil material to produce the unique deposits that we see evident in many of the chambers of the Naracoorte Cave system today

Predicting travel times and transport characterization in karst conduits by analyzing tracer-breakthrough curves, ,
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Morales Tomas, De Valderrama Inigo, Uriarte Jesus A. , Antiguedad Inaki, Olazar Martin,
SummaryThis paper analyzes data obtained in 26 tracer tests carried out in 11 karstic connections following solutional conduits in karst aquifers in the Basque Country. These conduits are preferential drainage pathways in these aquifers and so they confer a marked anisotropy and high vulnerability to them. Consequently, their consideration in protection and management studies and projects is a priority.The connections studied cover a wide hydrogeological spectrum (a wide range of sizes, slopes, geomorphic and hydrologic types) and the tests have been carried out at different hydrodynamic states. It is noteworthy that they all follow a similar trend, which has allowed for the development of a statistical approximation for the treatment of the whole information.Relationships have been established involving velocity, solute time of arrival, attenuation of peak concentration and time of passage of tracer cloud. These relationships are a valuable tool for management and supporting decision-making and allow for making estimates in connections in which the information available was scarce. This information is especially useful, given that the complexity of transport in karst conduits gives way to important deviations between real data (empirical observations) and the data obtained by simple approaches based on the Fickian-type diffusion equation

Controversy over the great flood hypotheses in the Black Sea in light of geological, paleontological, and archaeological evidence, ,
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Yankohombach Valentina, Gilbert Allan S. , Dolukhanov Pavel,
Legends describing a Great Flood are found in the narratives of several world religions, and the biblical account of Noah's Flood is the surviving heir to several versions of the ancient Mesopotamian Flood Myth. Recently, the story of the biblical deluge was connected to the Black Sea, together with the suggestion that the story's pre-Mesopotamian origins might be found in the Pontic basin [Ryan, W.B.F., Pitman, III, W.C., 1998. Noah's Flood: The New Scientific Discoveries About the Event That Changed History. Simon and Schuster, New York]. Based on the significance of this flood epic in the Judeo-Christian tradition, popular interest surged following publication of the idea.Currently, two Great Flood scenarios have been proposed for the Black Sea: (1) an Early Holocene event caused by catastrophic Mediterranean inflow at 7.2 ky BP (initial hypothesis of [Ryan et al., 1997. An abrupt drowning of the Black Sea shelf. Marine Geology 138, 119-126]) or 8.4 ky BP (modified hypothesis of [Ryan et al., 2003. Catastrophic flooding of the Black Sea. Annual Review of Earth and Planetary Science 31, 525-554.); and (2) a Late Pleistocene event brought on by Caspian influx between 16 and 13 ky BP [Chepalyga, A.L., 2003. Late glacial Great Flood in the Black Sea and Caspian Sea. GSA Annual Meeting and Exposition, 2-5 November 2003, Seattle, USA, p. 460]. Both hypotheses claim that the massive inundations of the Black Sea basin and ensuing large-scale environmental changes had a profound impact on prehistoric human societies of the surrounding areas, and both propose that the event formed the basis for the biblical Great Flood legend.This paper attempts to determine whether the preponderance of existing evidence sustains support for these Great Floods in the evolution of the Black Sea. Based upon established geological and paleontological data, it finds that the Late Pleistocene inundation was intense and substantial whereas the Early Holocene sea-level rise was not. Between 16 and 13 ky BP, the Late Neoeuxinian lake (the Late Pleistocene water body in the Pontic basin pre-dating the Black Sea) increased rapidly from ~-14 to -50 m (below the present level of the Black Sea), then rose gradually to ~-20 m by about 11 ky BP. At 11-10 ky BP (the Younger Dryas), it dropped to ~-50 m. When the Black Sea re-connected with the Sea of Marmara at about 9.5 ky BP, inflowing Mediterranean water increased the Black Sea level very gradually up to ~-20 m, and in so doing, it raised the salinity of the basin and brought in the first wave of Mediterranean immigrants. These data indicate no major drawdown of the Black Sea after the Younger Dryas, and they do not provide evidence for any catastrophic flooding of the Black Sea in the Early Holocene.In addition, available archaeological and paleoenvironmental evidence from the Pontic region reveal no recognizable changes in population dynamics between 14 and 6 ky BP that could be linked to an inundation of large magnitude [Dolukhanov, P., Shilik, K., 2006. Environment, sea-level changes, and human migrations in the northern Pontic area during late Pleistocene and Holocene times. In: Yanko-Hombach, V., Gilbert, A.S., Panin, N., Dolukhanov, P.M. (Eds.), The Black Sea Flood Question: Changes in Coastline, Climate, and Human Settlement. Springer, Dordrecht, pp. 297-318; Stanko, V.N., 2006. Fluctuations in the level of the Black Sea and Mesolithic settlement of the northern Pontic area. In: Yanko-Hombach, V., Gilbert, A.S., Panin, N., Dolukhanov, P.M. (Eds.), The Black Sea Flood Question: Changes in Coastline, Climate, and Human Settlement. Springer, Dordrecht, pp. 371-385]. More specifically, Mesolithic and early Neolithic archaeological data in southeastern Europe and Ukraine give no indications of shifts in human subsistence or other behavior at the time of the proposed catastrophic flood in the Early Holocene [Anthony, D., 2006. Pontic-Caspian Mesolithic and Early Neolithic societies at the time of the Black Sea Flood: A small audience and small effects. In: Yanko-Hombach, V., Gilbert, A.S., Panin, N., Dolukhanov, P.M. (Eds.), The Black Sea Flood Question: Changes in Coastline, Climate, and Human Settlement. Springer, Dordrecht, pp. 345-370; Dergachev and Dolukhanov, 2006. The Neolithization of the North Pontic area and the Balkans in the context of the Black Sea Floods. In: Yanko-Hombach, V., Gilbert, A.S., Panin, N., Dolukhanov, P.M. (Eds.), The Black Sea Flood Question: Changes in Coastline, Climate, and Human Settlement. Springer, Dordrecht, pp. 489-514]

Breccia and Pennsylvanian cave filling in Mississippian Saint Louis Limestone, Putnam County, Indiana, 1961,
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Smith Ned Myron, Sunderman Jack Allen, Melhorn Wilton Newton,
A limestone breccia and several bodies of shale and sandstone in Mississippian St. Louis limestone were discovered in a quarry opened during the summer of 1959 in the SE1/4NW1/4 sec. 15, T.15N., R.4W., Putnam County. A small mass of sandy limestone conglomerate overlay part of the breccia. Nearly all these bodies have been removed in quarrying. The breccia and the shale-sandstone masses appear to have originated from 2 separate geologic processes which occurred at 2 different times. The origin of the breccia is in doubt because not enough critical evidence is available to prove conclusively and single origin. The authors believe, however, that the breccia probably is the product of a submarine rock slump during St. Louis time which was triggered by the tectonic activity that initiated early movements along the Mt. Carmel fault. Other possible origins, such as solution of evaporites accompanied by collapse of overlying rock or formation of caves in a karst terrain followed by roof collapse, are not supported by the evidence observed. The shale-sandstone bodies are believed to be rocks of Pennsylvanian age which were deposited in caverns developed during the Mississippian-Pennsylvanian erosion interval. The limestone conglomerate is probably of the same age as the shale-sandstone bodies

The meaning of Pleistocene birdfauna of Hungarian Middle Mountain caves., 1964,
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Farkas Tibor
In the present study, the fossil bird fauna of the caves of the Hungarian Middle Mountains is examined for evidence in support of the hypothesis that the Carpathian Basin may have served as a faunal refugee during the last Quaternary glacial period. As an introduction, the reasons for the refugee hypothesis, including paleobotanical and glacial theoretical aspects, are discussed. Since the first bird fossils of the cave fauna considered in this paper belong to the Wrm I-II, the faunistic conditions of the Riss glacial period are not discussed in detail, The known faunas up to the Wrm II are interstadial, which seems to serve only as indirect support for the refugee hypothesis. Paleobotanical evidence, both for and against the hypothesis, is also considered. In conclusion, the abundant cave faunas of all phases of the Wrm III are cited as being; at least at the present time; the most convincing argument for the refugee hypothesis. The heterogeneous composition of these faunas permits certain tentative conclusions regarding the faunas of Wurm I and II.

Ecology of Fonticola notadena de Beauchamp (Turbellaria, Triclade) in the La Balme cave (Isre, France); suvival in a dry period., 1964,
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Ginet Rene, Puglisi Rodolphe
During many months a year the acquatic Planaria (F. notadena) living in a small pool in the La Balme cave are subjected to a drought with the complete drying out of their biotope; they support in situ this lack of water and, living in a latent way inside the clayey matrix. Thanks to the great hygroscopy of the clay, enough humidity stays around the Planarians to enable them to survive. During this period the Planaria may undergo spontaneous divisions resulting in their asexual multiplication.

Algological studies in the cave of Matyas Mount, Budapest, Hungary., 1966,
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Hajdu Lajos.
Experiments were designed to test the ability of the aphotic speleoenvironment to support algal growth. The first series contained gelatin cultures of Scenedesmus placed in the cave at different localities in order to establish whether or not the microhabitats have any particular effect on the multiplication of the algae. No differences were found in the cultures after a three month incubation period in the cave, which could be traced to influences of microenvironmental conditions. Chlorella cultures in sterile Knop's solution showed measurable growth in the cave whereas if the cultures were installed into sterilized cave water or were shielded by lead against possible radiation effects, no appreciable growth occurred. The presence or absence of magnetic field did not noticeably influence algal development. The experiments seemed to indicate that the algae tested are able to utilize soma kind of radiation in the complete darkness of the cava since, in the absence of organic material, appreciable amounts of molecular hydrogen or symbiotic activity, with iron bacteria, considerable growth occurred in a simple, strictly inorganic medium, whereas the cave waters seam to be deficient in some kind of inorganic salt required for algal nutrition. An investigation of algae living in the cave led to the determination of ten different taxa, the majority of which were Cyanophytes. Besides them, however, the cave may contain a more diversified algal population.

Further Remarks on the Big Hole, Near Braidwood, New South Wales, 1967,
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Jennings, J. N.

The new data from the Big Hole and its vicinity give some further support to the view maintained previously as to its origin, though an approach through water chemistry proved non-committal. Difficulties attaching to an origin by true phreatic solution of underlying limestone through circulations of groundwater of meteoric provenance remain however. Nevertheless, the possibility, not considered previously, that the Big Hole is due to hydrothermal solution in the manner of many collapse structures associated with uranium ore bodies in southwestern U.S.A. finds no support in the regional geology of the Shoalhaven valley, though it could produce features of the right dimensions. Previous lack of a complete parallel to the Big Hole has been removed by reference to the furnas of southern Brazil where a similar origin to the one proposed here is also inferred.

Cave Development during a Catastrophic Storm in the Great Valley of Virginia, 1971,
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Doehring Do, Vierbuchen Rc,
Observations made before aind after a catastrophic storml support the conclutsion that caves receivinig storm recharge may be significantly developed in the vadose zone by the processes of niass transfer. These processes are greatly accelerated during times of major floods. Evidence indicates that in ancient times floods of similar magnitude have occurred

Caves of Kitava and Tuma, Trobriand Islands, 1971,
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Ollier C. D. , Holdsworth D. K. , Heers G.

The Trobriand group of coral islands is situated a hundred miles off the north-east coast of Papua and north of the D 'Entr'ecasteaux Islands. In previous papers we have described caves on Kiriwina (the main island), Vakuta and Kitava (see References). We now describe caves of Kaileuna and Tuma (see Figures l and 2). In August 1970, we spent one week of intensive search for caves on these two islands, making our headquarters in the copra store in the village of Kadawaga. Kaileuna island is six miles long and almost four miles wide, and supports a population of 1,079 (1969 Census). It is separated from the large island of Kiriwina by a channel two miles wide between Mamamada Point and Boll Point, though the main village of Kadawaga on the west coast of Kaileuna is 18 miles from Losuia and 14 miles from Kaibola. The island is generally swampy in the centre with a rim of uplifted coral around the edge. We were assured that the correct name of the island is Laileula, but since Kaileuna is used on all previous maps it is retained here. However, we prefer Kadawaga to the Kudawaga or Kaduwaga that appear on some maps. The inhabitants are of mixed Melanesian-Polynesian Stock, who are almost totally self-supporting, being in the main farmers and fishermen. The yam (taitu) constitutes the staple crop and the harvest is still gathered in with ceremonies unchanged for centuries. There is great competition among families for the quantity and quality of the crop, which is displayed firstly in garden arbours (kalimonio), later in the village outside the houses; traditionally styled yam huts (bwaima) are then constructed to display the harvest until the next season. The transfer of yams from the garden to the village is occasion for a long procession of gatherers to parade through the village blowing conch shells and chanting traditional airs (sawili) to attract the attention of villagers to the harvesting party, After storage of the harvest, a period of dancing and feasting (milamala) continues for a month or more, Traditional clothing is the rule, Women and girls wear fibre skirts (doba), most of the men, especially the older ones, wear a pubic leaf (vivia) made from the sepal of the betel nut palm flower (Areca catechu Linn.). Tuma, the northernmost of the main islands in the Trobriand group, is six miles long and less than a mile wide. It is a low ridge of coral with swamps in the centre and along much of the western side. The island has been uninhabited since 1963 when the last few residents abandoned it and moved to Kiriwina, but it is still visited from time to time by other islanders who collect copra and fish. Tuma is believed by all Trobriand Islanders to be inhabited now by the spirits of the dead. It is also generally believed that Tuma is the original home of the TrobIiand ancestors; these ancestors are also said to have emerged at Labai Cave on Kiriwina Island, and from many other places of emergence or 'bwala". Lack of consistency in the legends does not appear to concern the Trobrianders very much. The cave maps in this paper are sketches based mainly on estimated dimensions, with a few actual measurements and compass bearings. Bwabwatu was surveyed more accurately, using a 100 ft steel reinforced tape and prismatic compass throughout.

Observations at the Blue Waterholes, March 1965 - April 1969, and Limestone Solution on Cooleman Plain, N.S.W., 1972,
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Jennings, J. N.

After brief descriptions of the geomorphology of the Cooleman Plain karst and in particular of the Blue Waterholes, the methods adopted to analyse the functioning of these major risings are detailed. The discharge regime of Cave Creek below them is oceanic pluvial in type perturbed by drought and snow. There is much annual variation both in seasonal incidence and total amount, with catchment efficiency correspondingly variable. Suspended sediment concentration is even more erratic and monthly determinations are inadequate for calculating corrasional denudation rates. Mean concentrations of suspended solids are about 1/18th of solute load. Total dissolved salts have a strong inverse relationship with discharge, and mean values are high compared with those for other catchments in eastern Australia but none of these determinations are from limestone catchments. Sodium, potassium, and chlorine contents are low compared with the same catchments but silica is relatively high. The ratio of alkaline earths to alkalis indicate that Cave Creek carries carbonate waters and there is an inverse regression of the ratio on discharge. There is inverse correlation of total hardness on discharge likewise due to concentration of surface waters by evaporation in dry periods, together with reduced underground solution rate at times of large, rapid flow. The spring waters remain aggressive. Close regressions of hardness on specific conductivity now permit the latter to be determined in the place of the former. Much evidence converges to indicate that all the springs at the Blue Waterholes are fed from the same conduit. The intermittent flow which comes down the North Branch on the surface to the Blue Waterholes differs significantly in many characters from the spring waters. Rates of Ca + M carbonate equivalent removal vary directly with discharge since hardness varies much less than does water volume. These gross rates have to be adjusted for (a) atmospheric salts entering the karst directly, (b) peripheral solute inputs from the non-karst two-thirds of the catchment and (c) subjacent karst solution before they can be taken as a measure of exposed karst denudation. The methods for achieving this are set out. The total corrections amount to about one third of the total hardness, though the correction for subjacent karst on its own lies within the experimental error of the investigation. The residual rate of limestone removal from the exposed karst also shows a winter/spring high rate and a summer/autumn low rate but the seasonal incidence and annual total varied very much from year to year. In comparison with results from karsts in broadly similar climate, the seasonal rhythm conforms and so does the high proportion (78%) of the solution taking place at or close to the surface. This reduces the importance of the impounded condition of this small karst but supports the use of karst denudation rate as a measure of surface lowering. Cave passage solution may however be more important in impounded karst than its absolute contribution might suggest, by promoting rapid development of underground circulation. The mean value of limestone removal is low for the climatic type and this is probably due to high evapotranspirational loss as well as to the process of eliminating atmospheric, peripheral non-karst and subjacent karst contributions. The difficulties of applying modern solution removal rate to the historical geomorphology of this karst are made evident; at the same time even crude extrapolations are shown to isolate problems valuably.

The Migration of Cave Arthropods Across The Nullarbor Plain, Southern Australia, 1972,
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Richards, Aola, M.

The Nullarbor Plain is a low plateau of Tertiary limestone covering an area of 194,175 km2 in southern Australia. It has a semi-arid climate and supports a stunted vegetation. Ninety-five species of arthropods have been recorded from 47 Nullarbor caves, and many of these species are widely distributed across the Plain. Two possible explanations for their distribution are discussed. Subterranean migration may occur through the widespread zone of small interconnecting cavities in the Nullarbor Limestone, but this has not yet been confirmed. While cave arthropods are confined to the cool, moist cave environment during the day, they have been observed at night in cave entrances, in dolines and on the surface of the Plain. Cave "breathing", similarity in cave and epigean climate at night, strong winds, occasional heavy rain and numerous animal burrows all contribute towards favourable conditions for surface migration.

The evolution of the Eastern North American Isopods of the Genus Asellus (Crustacea: Asellidae)., 1973,
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Fleming Laurence E.
This paper is the second in the three part series dealing with the evolution of the North American isopods of the genus Asellus. The generic status of Asellus is discussed with emphasis placed on the newly proposed genera of Henry and Magniez (1968). Use is made of comparative anatomical and where feasible statistical methods during this investigation. The first, shorter portion of the study deals with the presentation of evidence supporting the viewpoint that if 'Pseudobaicalasellus" is to be considered a valid genus then it must include the members of the Cannulus Group of Steeves (1965). The second portion of the study is concerned with the determination of the generic status of the eastern North American isopods. From the data presented it is felt that it is inadvisable to elevate species; groups of Asellus to the rank of genera. A generic diagnosis of the genus Asellus is presented. A list of North American species of the genus Asellus as well as a key to North American species of Asellus is included. The reduction to synonymy of certain nominal species of the genus Asellus is also given.

The natural populations of Stenasellus virei Dollfus (trgoglobic Crustacea Asellota)., 1973,
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Magniez Guy
Many cavernicolous and phreatic localities are known for the species Stenasellus virei. Some of these, which harbor a rather abundant population have been studied for several years. The endemic populations from permanent waters of some fossil karstic systems seem to have an abnormal composition. They include especially large individuals (juvenile stages being rare). They differ from the phreatic populations, which exhibit a normal distribution in size groups with a normal percentage of juveniles. These differences in the structure of populations may result from physical differences between the habitat in free waters of caves and in phreatic water, and from differences between the associations of species that these two types of hypogean habitat may support.

Ecological and evolutive aspects of the communities of temperate and tropical caves: observations on the biological cycles of some species of Ptomaphagus (Coleoptera Catopidae)., 1973,
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Sbordoni Marina Cobolli, Sbordoni Valerio
Differences between tropical and temperate cave communities are an important topic in the actual biospeleological thinking. Among the most striking differences is the paucity of terrestrial troglobites in tropical caves. This fact may depend on the higher energy input into tropical caves which lessens the selection pressures for energy-economizing troglobite adaptations. Consequently evolutionary rates would be slowed in tropical caves and, in a date group, troglobites would appear later in such caves than in temperate ones with lower energy input. In order to investigate this point the authors studied the degree of adaptation to the cave environment in two species of Mexican Ptomaphagus which, being phylogenetically related, probably descend from the same epigean ancestor. Among these species the first one, P. troglomexicanus Peck, lives in a typical temperate cave (i.e. cold, high altitude cave, with scarce food supply) in the Sierra de Guatemala (Tamaulipas), the other one, P. spelaeus (Bilimek), populates tropical caves (i.e. warm, lowland cave, with rich food supply) in the State of Guerrero. In addition a comparison is made with P. pius Seidlitz, an epigean species from southern Europe. The results show a striking difference between P. troglomexicanus on a side and the other two species. Differences chiefly concern morphological features such as relative antenna length, structural complexity (i.e. the number of sensilla) of the antenna chemioreceptor organs in the 70, 90, 100 segments, degree of reduction of eye, wing and pigmentation and physiological ones such as the length of the life cycle. The possible causes of these differences are discussed. According to the authors these differences appear due to the different selection pressures acting in the two types of caves. In addition a comparison between the "tropical cave" species, P. spelaeus, with the epigean one, P. pius, does not point out the differences that one could expect by the diverse ecology of these species. These observations support the idea that evolutionary rates in cavernicoles are strongly affected by the ecology of the cave, mainly depending on the degree of energy input, and are poorly consistent with the hypothesis that mutations affecting degenerative processes are selectively neutral.

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