Eleven species of the freshwater isopod genus Lirceus occur in the Interior Highlands, a region of the south-central United States comprised of the Ozark and Ouachita physiographic provinces. As part of research on the morphology and molecular genetics of eastern North American asellid isopods, three new species of Lirceus were discovered in the Interior Highlands. Lirceus slayorum, n. sp., is described from Greathouse Spring, Washington County, Arkansas and occurs in caves and springs associated with the Ozark Springfield Plateau. Lirceus ozarkensis, n. sp., is described from Maxey Cave, Pulaski County, Missouri and was originally identified in 1949 by Hubricht and Mackin as a subspecies of Lirceus hoppinae. In actuality, L. ozarkensis is quite distinct from L. hoppinae, and occurs allopatrically in caves and springs of the southern Ozark Salem Plateau in southern Missouri. Lirceus robisoni, n. sp., is described from Abernathy Spring, Polk County, Arkansas and is found in only a few springs in a narrow area of the Ouachita Mountains in western Arkansas. Eight other species of Lirceus occur in the Interior Highlands, most of which are confined to springs and caves. New localities are presented and the ranges of the species are established. Illustrations of the genital pleopods demonstrate a common theme across the species of the Interior Highlands, with all possessing a sperm-transfer cannula arising adjacent to a variously papillate or dentate digitiform lateral process, and nestled under a dominant broadly rounded or subtriangular apex. Within this morphological template, some of the Ozark species, like Lirceus bidentatus, are among the most anatomically bizarre in North America.
{"title":"Freshwater isopods of the genus Lirceus from caves and springs of the Interior Highlands, USA, with description of three new species (Isopoda: Asellidae)","authors":"Julian Lewis, Salisa Lewis","doi":"10.4311/2022lsc0113","DOIUrl":"https://doi.org/10.4311/2022lsc0113","url":null,"abstract":"Eleven species of the freshwater isopod genus Lirceus occur in the Interior Highlands, a region of the south-central United States comprised of the Ozark and Ouachita physiographic provinces. As part of research on the morphology and molecular genetics of eastern North American asellid isopods, three new species of Lirceus were discovered in the Interior Highlands. Lirceus slayorum, n. sp., is described from Greathouse Spring, Washington County, Arkansas and occurs in caves and springs associated with the Ozark Springfield Plateau. Lirceus ozarkensis, n. sp., is described from Maxey Cave, Pulaski County, Missouri and was originally identified in 1949 by Hubricht and Mackin as a subspecies of Lirceus hoppinae. In actuality, L. ozarkensis is quite distinct from L. hoppinae, and occurs allopatrically in caves and springs of the southern Ozark Salem Plateau in southern Missouri. Lirceus robisoni, n. sp., is described from Abernathy Spring, Polk County, Arkansas and is found in only a few springs in a narrow area of the Ouachita Mountains in western Arkansas. Eight other species of Lirceus occur in the Interior Highlands, most of which are confined to springs and caves. New localities are presented and the ranges of the species are established. Illustrations of the genital pleopods demonstrate a common theme across the species of the Interior Highlands, with all possessing a sperm-transfer cannula arising adjacent to a variously papillate or dentate digitiform lateral process, and nestled under a dominant broadly rounded or subtriangular apex. Within this morphological template, some of the Ozark species, like Lirceus bidentatus, are among the most anatomically bizarre in North America.","PeriodicalId":50244,"journal":{"name":"Journal of Cave and Karst Studies","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2023-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139130817","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Christian Stenner, Lee Florea, A. Pflitsch, E. Cartaya, David Riggs
The twin summit craters of Mount Rainier, Washington, USA host the largest known glaciovolcanic caves in the world and at 4382 m, the highest elevation caves in the USA. The caves are formed in ice at the glacier-rock interface by volcanogenic gases and atmospheric advection. However, the way in which discrete caves are formed and evolve remains poorly understood. Surveys of the cave systems in 1970−1973 and 1997−1998 in both the West and East Craters documented cave passage morphology. Field expeditions from 2014−2017 comprehensively surveyed the Rainier summit caves and undertook thermal imaging and temperature monitoring. Significant changes had occurred. In the East Crater, documented cave length has nearly doubled since 1973 to 3593 m of passage spanning 144 m of depth, revealing a new subglacial lake, and now nearly circumnavigating the East Crater. Of the reported increase in length, some 600 m of the mapped passage is possibly newly formed. Across 47 years of observation, certain sections of the cave appear to be preserved in form and position through time, while others are more actively being lost or forming. Conserved passages are generally sub-horizontal, passages following the curvilinear crater contours, show low temperature variability, and are dependent on perennial fumarolic activity or distributed heat flux emanating from warm bedrock and sediment floors. Transient passages are smaller diameter dendritic passages following the slope of the ice-rock interface towards entrance zones and normal to the circum-crater passage. They also show higher variability in temperature and airflow and are subject to seasonal weather and mechanical collapse, which may contribute to transience. Additional research is required to confirm the mechanisms maintaining conserved passages and formation of transient passages.
{"title":"Morphodynamics of glaciovolcanic caves—Mount Rainier, Washington, USA","authors":"Christian Stenner, Lee Florea, A. Pflitsch, E. Cartaya, David Riggs","doi":"10.4311/2021ex0131","DOIUrl":"https://doi.org/10.4311/2021ex0131","url":null,"abstract":"The twin summit craters of Mount Rainier, Washington, USA host the largest known glaciovolcanic caves in the world and at 4382 m, the highest elevation caves in the USA. The caves are formed in ice at the glacier-rock interface by volcanogenic gases and atmospheric advection. However, the way in which discrete caves are formed and evolve remains poorly understood. Surveys of the cave systems in 1970−1973 and 1997−1998 in both the West and East Craters documented cave passage morphology. Field expeditions from 2014−2017 comprehensively surveyed the Rainier summit caves and undertook thermal imaging and temperature monitoring. Significant changes had occurred. In the East Crater, documented cave length has nearly doubled since 1973 to 3593 m of passage spanning 144 m of depth, revealing a new subglacial lake, and now nearly circumnavigating the East Crater. Of the reported increase in length, some 600 m of the mapped passage is possibly newly formed. Across 47 years of observation, certain sections of the cave appear to be preserved in form and position through time, while others are more actively being lost or forming. Conserved passages are generally sub-horizontal, passages following the curvilinear crater contours, show low temperature variability, and are dependent on perennial fumarolic activity or distributed heat flux emanating from warm bedrock and sediment floors. Transient passages are smaller diameter dendritic passages following the slope of the ice-rock interface towards entrance zones and normal to the circum-crater passage. They also show higher variability in temperature and airflow and are subject to seasonal weather and mechanical collapse, which may contribute to transience. Additional research is required to confirm the mechanisms maintaining conserved passages and formation of transient passages.","PeriodicalId":50244,"journal":{"name":"Journal of Cave and Karst Studies","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2023-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139129944","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The late Cretaceous Mancos Shale in western Colorado contains several vadose caves developed entirely within the shale. The largest of these, Rock Pigeon Cave, is over 300 m in length and contains a seasonal stream. The cave, and others like it, is hypothesized to develop as a result of the oxidation of disseminated pyrite in the shale by descending meteoric water with resulting sulfate ions reacting with the carbonate component of the shale to produce gypsum. The gypsum pries apart the shale, increasing its secondary porosity, and allows flowing water to remove shale particles via corrasion. As these particles are removed, they are transported down-gradient to an outlet, allowing continuous openings (cave passages) to develop. Extensive sulfate mineralization is observed within the cave and takes several forms: soft globular deposits on rocks at water level, a white to tan crust on shale surfaces, dry crusts on the passage floor following evaporation of pools, and needle and hair-like extrusions on passage walls. Powder X-ray diffraction (XRD) indicates that these deposits are a mixture of thenardite and blodite with lesser amounts of gypsum, hexahydrite, and konyaite. Na+, Mg2+, and SO4 2- ions in the entering stream are the source of the sulfate minerals at stream level and on the wetted slopes above. These come out of solution as the cave stream and pools evaporate with sulfates precipitating as saturation is reached. Fibrous, needle-like sulfates on walls above the wetted zone are a result of crystallization by evaporation: fluids containing sulfate ions are extruded and evaporate at the rock/air interface. Other minerals, e.g., deposits containing goethite and jarosite, are seen on passage walls as reaction products from oxidation of pyrite in the shale.
科罗拉多州西部白垩纪晚期的曼科斯页岩中有几个完全发育在页岩中的岩溶洞。其中最大的岩鸽洞长度超过 300 米，内有一条季节性溪流。据推测，该洞穴以及其他类似洞穴的形成，是由于流星水冲刷页岩中的黄铁矿，硫酸根离子与页岩中的碳酸盐成分发生反应，生成石膏。石膏将页岩撬开，增加了页岩的二次孔隙率，使流水可以通过腐蚀作用带走页岩颗粒。当这些颗粒被带走时，它们就会被向下输送到出口处，从而形成连续的开口（洞穴通道）。在洞穴内可以观察到广泛的硫酸盐矿化现象，有多种形式：水位处岩石上的软球状沉积物、页岩表面的白色至棕褐色结壳、水池蒸发后通道地面上的干燥结壳以及通道壁上的针状和毛发状挤压物。粉末 X 射线衍射（XRD）表明，这些沉积物是霞石和白云石的混合物，还有少量石膏、六水石和孔雀石。溪流中的 Na+、Mg2+ 和 SO4 2- 离子是溪流水平面和上方湿润斜坡上硫酸盐矿物的来源。随着洞穴溪流和水池的蒸发，这些矿物质从溶液中析出，当达到饱和状态时，硫酸盐沉淀。湿润区上方岩壁上的纤维状、针状硫酸盐是蒸发结晶的结果：含有硫酸根离子的流体被挤出并在岩石/空气界面蒸发。通道壁上的其他矿物，例如含有鹅卵石和箭石的沉积物，是页岩中黄铁矿氧化的反应产物。
{"title":"Rock Pigeon Cave, Colorado: development and mineralogy","authors":"Douglas Medville","doi":"10.4311/2023es0104","DOIUrl":"https://doi.org/10.4311/2023es0104","url":null,"abstract":"The late Cretaceous Mancos Shale in western Colorado contains several vadose caves developed entirely within the shale. The largest of these, Rock Pigeon Cave, is over 300 m in length and contains a seasonal stream. The cave, and others like it, is hypothesized to develop as a result of the oxidation of disseminated pyrite in the shale by descending meteoric water with resulting sulfate ions reacting with the carbonate component of the shale to produce gypsum. The gypsum pries apart the shale, increasing its secondary porosity, and allows flowing water to remove shale particles via corrasion. As these particles are removed, they are transported down-gradient to an outlet, allowing continuous openings (cave passages) to develop. Extensive sulfate mineralization is observed within the cave and takes several forms: soft globular deposits on rocks at water level, a white to tan crust on shale surfaces, dry crusts on the passage floor following evaporation of pools, and needle and hair-like extrusions on passage walls. Powder X-ray diffraction (XRD) indicates that these deposits are a mixture of thenardite and blodite with lesser amounts of gypsum, hexahydrite, and konyaite. Na+, Mg2+, and SO4 2- ions in the entering stream are the source of the sulfate minerals at stream level and on the wetted slopes above. These come out of solution as the cave stream and pools evaporate with sulfates precipitating as saturation is reached. Fibrous, needle-like sulfates on walls above the wetted zone are a result of crystallization by evaporation: fluids containing sulfate ions are extruded and evaporate at the rock/air interface. Other minerals, e.g., deposits containing goethite and jarosite, are seen on passage walls as reaction products from oxidation of pyrite in the shale.","PeriodicalId":50244,"journal":{"name":"Journal of Cave and Karst Studies","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2023-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139134074","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Iron oxide deposits in the form of crusts are examined in the field and in the laboratory with scanning electron microscopy. Samples came from two caves developed in different geological settings but assumed by previous studies to be of hydrothermal-hypogene origin. The relation of iron oxide crusts to cave wall and ceiling morphology created by the cave’s primary dissolution (speleogenesis), as well as to the formation of other speleothems, is investigated. Scanning electron microscope (SEM) elemental analysis showed a high iron content (20–78 % by weight) consistent with iron oxide minerals such as goethite, hematite, magnetite, etc. Three distinct types of iron oxide crusts were identified from the four samples that were analyzed: (1) high iron content crusts with some porosity formed on the host rock surface and discontinuities, (2) high iron content (but lower than type 1) crusts, including limestone clasts and pores originating from dissolved clasts, and (3) high iron content, significantly-porous crusts that are formed by a network of filaments that indicate microbial activity. The formation of these deposits in relation to other speleothems and to dissolution events is discussed.
{"title":"Contribution to the Ostracoda (crustacea) Fauna of the karstic region of Texas with the description of a new species","authors":"Georgios Lazaridis, Lambrini Papadopoulou, Vasilios Melfos, Panagiotis Voudouris","doi":"10.4311/2022es0100","DOIUrl":"https://doi.org/10.4311/2022es0100","url":null,"abstract":"Iron oxide deposits in the form of crusts are examined in the field and in the laboratory with scanning electron microscopy. Samples came from two caves developed in different geological settings but assumed by previous studies to be of hydrothermal-hypogene origin. The relation of iron oxide crusts to cave wall and ceiling morphology created by the cave’s primary dissolution (speleogenesis), as well as to the formation of other speleothems, is investigated. Scanning electron microscope (SEM) elemental analysis showed a high iron content (20–78 % by weight) consistent with iron oxide minerals such as goethite, hematite, magnetite, etc. Three distinct types of iron oxide crusts were identified from the four samples that were analyzed: (1) high iron content crusts with some porosity formed on the host rock surface and discontinuities, (2) high iron content (but lower than type 1) crusts, including limestone clasts and pores originating from dissolved clasts, and (3) high iron content, significantly-porous crusts that are formed by a network of filaments that indicate microbial activity. The formation of these deposits in relation to other speleothems and to dissolution events is discussed.","PeriodicalId":50244,"journal":{"name":"Journal of Cave and Karst Studies","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136370286","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A total of 27 ostracod taxa were collected from 1995 to 2017 from 61 aquatic bodies in the karstic region of Texas (USA) and 1 in Mexico, including from caves, springs, spring-fed pools, and springs/drips in karstic rock-shelters. Among these taxa, Dolerocypris reyesi sp. nov. is a new species collected from a shallow pool connected to the springs above a rock-shelter. Three species (Penthesilenula aotearoa, P. incae, and Vestalenula marmonieri) are reported for the first time from North America. In addition, Typhlocypris cf. prespica and 4 taxa (Microdarwinula zimmeri, Cypridopsis cf. herpestica, Pseudocandona cf. parallela, P. cf. pratensis) are new records of ostracod fauna of the US and Texas, respectively. The phylogenetic results based on 31 taxa and 30 morphological characters revealed 4 subgroups belonging to 6 main clustering groups within the family Darwinulidae. Including the new species reported here, the total number of non-marine ostracods in Texas is increased to 115 species. The results indicate that the total number of species is far below the true diversity and richness of the state.
{"title":"Contribution to the Ostracoda (crustacea) Fauna of the karstic region of Texas with the description of a new species","authors":"Okan Külköylüoğlu, Alaettin Tuncer","doi":"10.4311/2021lsc0120","DOIUrl":"https://doi.org/10.4311/2021lsc0120","url":null,"abstract":"A total of 27 ostracod taxa were collected from 1995 to 2017 from 61 aquatic bodies in the karstic region of Texas (USA) and 1 in Mexico, including from caves, springs, spring-fed pools, and springs/drips in karstic rock-shelters. Among these taxa, Dolerocypris reyesi sp. nov. is a new species collected from a shallow pool connected to the springs above a rock-shelter. Three species (Penthesilenula aotearoa, P. incae, and Vestalenula marmonieri) are reported for the first time from North America. In addition, Typhlocypris cf. prespica and 4 taxa (Microdarwinula zimmeri, Cypridopsis cf. herpestica, Pseudocandona cf. parallela, P. cf. pratensis) are new records of ostracod fauna of the US and Texas, respectively. The phylogenetic results based on 31 taxa and 30 morphological characters revealed 4 subgroups belonging to 6 main clustering groups within the family Darwinulidae. Including the new species reported here, the total number of non-marine ostracods in Texas is increased to 115 species. The results indicate that the total number of species is far below the true diversity and richness of the state.","PeriodicalId":50244,"journal":{"name":"Journal of Cave and Karst Studies","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136370285","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Natasha Sekhon, Jay Banner, Dan Breecker, Darrel Tremaine
Stalagmites being prepared for paleoclimate analysis should typically be slabbed along the central growth axis. This is an important first step because it allows for the highest resolution of sampling with minimal over- or under-sampling of the growth layers. Further, stable isotope ratios and trace element concentrations along the central growth axis most closely record climate variability. Choosing how to slab to best expose the central growth axis for geochemical sampling is challenging based on external morphology alone. High-resolution X-ray computed tomography (XRCT) can provide the ability to discern the internal growth morphology of stalagmites non-destructively, inexpensively, and rapidly. These data can inform selection of optimal slabbing plane(s) and can help identify locations for preliminary U-series dating. We develop a conceptual screening model to assess rapidly the internal morphologies of uncut stalagmites. The specifics of screening the internal morphologies through XRCT scans include investigating the internal porosity of the sample, the number and size of voids and hiatuses, and the presence and absence of growth layers and growth axes. We demonstrate that XRCT scans capture the migration of center of growth in uncut stalagmites of both simple and complex internal morphologies. XRCT scanning facilitates the investigation of stalagmites with complex internal growth banding, opening up avenues to work on such samples when stalagmites with simpler internal morphologies are not available. Further, screening stalagmites for paleoclimate reconstructions using XRCT improves the sustainability of speleothem science by helping researchers select which stalagmites should be returned to caves without destructive slabbing, thereby minimizing impact on caves.
{"title":"Using High-Resolution X-Ray Computed Tomography to Test the Preparation of Stalagmites for Paleo-Climate Reconstruction","authors":"Natasha Sekhon, Jay Banner, Dan Breecker, Darrel Tremaine","doi":"10.4311/2021es0122","DOIUrl":"https://doi.org/10.4311/2021es0122","url":null,"abstract":"Stalagmites being prepared for paleoclimate analysis should typically be slabbed along the central growth axis. This is an important first step because it allows for the highest resolution of sampling with minimal over- or under-sampling of the growth layers. Further, stable isotope ratios and trace element concentrations along the central growth axis most closely record climate variability. Choosing how to slab to best expose the central growth axis for geochemical sampling is challenging based on external morphology alone. High-resolution X-ray computed tomography (XRCT) can provide the ability to discern the internal growth morphology of stalagmites non-destructively, inexpensively, and rapidly. These data can inform selection of optimal slabbing plane(s) and can help identify locations for preliminary U-series dating. We develop a conceptual screening model to assess rapidly the internal morphologies of uncut stalagmites. The specifics of screening the internal morphologies through XRCT scans include investigating the internal porosity of the sample, the number and size of voids and hiatuses, and the presence and absence of growth layers and growth axes. We demonstrate that XRCT scans capture the migration of center of growth in uncut stalagmites of both simple and complex internal morphologies. XRCT scanning facilitates the investigation of stalagmites with complex internal growth banding, opening up avenues to work on such samples when stalagmites with simpler internal morphologies are not available. Further, screening stalagmites for paleoclimate reconstructions using XRCT improves the sustainability of speleothem science by helping researchers select which stalagmites should be returned to caves without destructive slabbing, thereby minimizing impact on caves.","PeriodicalId":50244,"journal":{"name":"Journal of Cave and Karst Studies","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135950618","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Many microorganisms secrete secondary metabolites with antibiotic properties; however, there is debate whether the secretions evolved as a means to gain a competitive edge or as a chemical signal to coordinate community growth. The objective of this research was to investigate if select antibiotics acted as a weapon or as a chemical signal by exposing communities of aquatic cave bacteria to increasing concentrations of antibiotics. Water samples were collected from six cave locations where actinobacterial mats appeared to be plentiful. Bacterial growth was measured using colony counts on 10 % tryptic soy agar augmented with increasing concentrations of erythromycin, tetracycline, kanamycin, gentamicin, or quaternary ammonia compounds (QAC). Colony counts generally decreased as the gentamicin, kanamycin and QAC dose increased. In contrast, the colony numbers increased on agar plates supplemented with 0.01 mg L−1, 0.10 mg L−1 and 1.00 mg L−1 erythromycin or tetracycline. A 10.00 mg L−1 dose of each antibiotic treatment reduced bacteria colonies by 98 % or more. Community-level physiological capabilities were evaluated using Ecolog plates inoculated with cave water dosed with either 0.00 mg L−1 or 0.10 mg L−1 of erythromycin. Incubation with the antibiotic almost doubled the number of food substrates used in the first 24 hours. There was a significant increase in the use of acetyl glucosamine, arginine, and putrescine when bacteria were exposed to 0.10 mg L−1 erythromycin triggered by the antibiotic acting as a chemical messenger. Principal component analysis confirmed a shift in substrate preferences when erythromycin was added. A conceptual ecological model is proposed based on the response of aquatic cave bacteria to sublethal antibiotics.
{"title":"Stimulation of Aquatic Bacteria from Mammoth Cave, Kentucky, by Sublethal Concentrations of Antibiotics","authors":"Thomas Byl","doi":"10.4311/2022mb0106","DOIUrl":"https://doi.org/10.4311/2022mb0106","url":null,"abstract":"Many microorganisms secrete secondary metabolites with antibiotic properties; however, there is debate whether the secretions evolved as a means to gain a competitive edge or as a chemical signal to coordinate community growth. The objective of this research was to investigate if select antibiotics acted as a weapon or as a chemical signal by exposing communities of aquatic cave bacteria to increasing concentrations of antibiotics. Water samples were collected from six cave locations where actinobacterial mats appeared to be plentiful. Bacterial growth was measured using colony counts on 10 % tryptic soy agar augmented with increasing concentrations of erythromycin, tetracycline, kanamycin, gentamicin, or quaternary ammonia compounds (QAC). Colony counts generally decreased as the gentamicin, kanamycin and QAC dose increased. In contrast, the colony numbers increased on agar plates supplemented with 0.01 mg L−1, 0.10 mg L−1 and 1.00 mg L−1 erythromycin or tetracycline. A 10.00 mg L−1 dose of each antibiotic treatment reduced bacteria colonies by 98 % or more. Community-level physiological capabilities were evaluated using Ecolog plates inoculated with cave water dosed with either 0.00 mg L−1 or 0.10 mg L−1 of erythromycin. Incubation with the antibiotic almost doubled the number of food substrates used in the first 24 hours. There was a significant increase in the use of acetyl glucosamine, arginine, and putrescine when bacteria were exposed to 0.10 mg L−1 erythromycin triggered by the antibiotic acting as a chemical messenger. Principal component analysis confirmed a shift in substrate preferences when erythromycin was added. A conceptual ecological model is proposed based on the response of aquatic cave bacteria to sublethal antibiotics.","PeriodicalId":50244,"journal":{"name":"Journal of Cave and Karst Studies","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135950619","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Rising temperatures and diminishing groundwater availability due to the current climate crisis are predicted to expose cave faunas in eastern North America to unprecedented environmental conditions that could prove detrimental to their unique ecosystems. Organisms that inhabit relatively stable environments like caves are known to develop narrow physiological tolerances. Cave habitats with their organisms are simple ecosystems whose homogeneity offers an ideal system for testing the ability of a highly specialized fauna to tolerate abiotic changes. We tested the capability of a cave-specialized beetle in the eastern United States, Darlingtonea kentuckensis Valentine, to withstand future climatic shifts in its environment. We exposed individuals to a range of relative humidities and temperatures for 10 days. The data strongly suggest that there is a temperature threshold for the survival of D. kentuckensis, but it is a higher thermal tolerance than would be expected in an environment that has not fluctuated in recent evolutionary time and suggests remnant physiological characteristics of ancestral epigean carabids. Decreasing the relative humidity in the environment resulted in a much more dramatic decline in survival, indicating highly evolved specialization for constant high-humidity environments. The narrow humidity threshold in which troglobionts can survive may be a much more apparent limiting factor than temperature in adapting to climatic shifts within a cave environment.
{"title":"Consequences of the global climate crisis on the cave beetle Darlingtonea Kentuckensis Valentine based on thermal tolerance and dehydration resistance","authors":"A. S. Apostolopoulos, T. K. Philips","doi":"10.4311/2021lsc0132","DOIUrl":"https://doi.org/10.4311/2021lsc0132","url":null,"abstract":"Rising temperatures and diminishing groundwater availability due to the current climate crisis are predicted to expose cave faunas in eastern North America to unprecedented environmental conditions that could prove detrimental to their unique ecosystems. Organisms that inhabit relatively stable environments like caves are known to develop narrow physiological tolerances. Cave habitats with their organisms are simple ecosystems whose homogeneity offers an ideal system for testing the ability of a highly specialized fauna to tolerate abiotic changes. We tested the capability of a cave-specialized beetle in the eastern United States, Darlingtonea kentuckensis Valentine, to withstand future climatic shifts in its environment. We exposed individuals to a range of relative humidities and temperatures for 10 days. The data strongly suggest that there is a temperature threshold for the survival of D. kentuckensis, but it is a higher thermal tolerance than would be expected in an environment that has not fluctuated in recent evolutionary time and suggests remnant physiological characteristics of ancestral epigean carabids. Decreasing the relative humidity in the environment resulted in a much more dramatic decline in survival, indicating highly evolved specialization for constant high-humidity environments. The narrow humidity threshold in which troglobionts can survive may be a much more apparent limiting factor than temperature in adapting to climatic shifts within a cave environment.","PeriodicalId":50244,"journal":{"name":"Journal of Cave and Karst Studies","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2022-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79305328","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Saint Anthony Cave is an important cultural, religious, and historic site; it was home of Saint Anthony, one of the earliest Christian monks (ca. 251–356 AD). The cave is located in a tectonically-complex karst area developed in partially dolomitic, sandy limestones of latest Paleocene age. Saint Anthony Cave had been described as a phreatic cave in previous research, but the cave lacked a detailed map and its speleogenesis was unclear. New data show the cave is a multi-phased uplifted cave formed primarily under phreatic conditions, with later modification by rising water levels. Deep sources of dissolutionally aggressive solutions likely have been involved. Speleogenesis likely began in Oligocene time associated with the Gulf of Suez Rift evolution and has been erosionally dissected. New, detailed mapping using ArcGIS shows the cave has an area of 22.13 m2 with a length and depth of 17.10 m and 5.33 m, respectively. The cave consists of a northwest–southeast oriented, steeply inclined, fracture controlled, upper-level entrance passage connected to an east–west oriented, fracture controlled, lower-level room with a vertical drop of 2.46 m. Dissolution pockets, cupola-like features, ceiling bell holes, notches, and corrosion tables are present in the cave. Subaerial and subaqueous speleothems moderately decorated the cave with likely Egyptian calcite alabaster. Based on field investigation, regional volcanic and tectonic history, paleoclimates, and other background information, we identify four distinct speleogenetic phases: First, during the late Oligocene, volcanic and extensional tectonic activities fractured the rocks, generated deep-seated acids, and enhanced the rising deep thermal water. Dissolution by other mechanisms such as carbonic/sulfuric acid and mixing dissolution were prevalent. In the early Miocene (Burdigalian), the cave was uplifted. Second, in the late Miocene (about 7.5 Ma), subaerial speleothems were being deposited in the cave under humid climate conditions. Third, post-Miocene, the cave enlarged and modified at and above the water level by likely warm, sulfuric water. Fourth, water levels dropped and speleothems were deposited again during later humid climate conditions.
{"title":"Saint Anthony Cave: Morphology, genesis, and age of one of the oldest religious shrines, Southern Galala Plateau, Eastern Desert, Egypt","authors":"W. Fahim","doi":"10.4311/2021ex0130","DOIUrl":"https://doi.org/10.4311/2021ex0130","url":null,"abstract":"Saint Anthony Cave is an important cultural, religious, and historic site; it was home of Saint Anthony, one of the earliest Christian monks (ca. 251–356 AD). The cave is located in a tectonically-complex karst area developed in partially dolomitic, sandy limestones of latest Paleocene age. Saint Anthony Cave had been described as a phreatic cave in previous research, but the cave lacked a detailed map and its speleogenesis was unclear. New data show the cave is a multi-phased uplifted cave formed primarily under phreatic conditions, with later modification by rising water levels. Deep sources of dissolutionally aggressive solutions likely have been involved. Speleogenesis likely began in Oligocene time associated with the Gulf of Suez Rift evolution and has been erosionally dissected. New, detailed mapping using ArcGIS shows the cave has an area of 22.13 m2 with a length and depth of 17.10 m and 5.33 m, respectively. The cave consists of a northwest–southeast oriented, steeply inclined, fracture controlled, upper-level entrance passage connected to an east–west oriented, fracture controlled, lower-level room with a vertical drop of 2.46 m. Dissolution pockets, cupola-like features, ceiling bell holes, notches, and corrosion tables are present in the cave. Subaerial and subaqueous speleothems moderately decorated the cave with likely Egyptian calcite alabaster. Based on field investigation, regional volcanic and tectonic history, paleoclimates, and other background information, we identify four distinct speleogenetic phases: First, during the late Oligocene, volcanic and extensional tectonic activities fractured the rocks, generated deep-seated acids, and enhanced the rising deep thermal water. Dissolution by other mechanisms such as carbonic/sulfuric acid and mixing dissolution were prevalent. In the early Miocene (Burdigalian), the cave was uplifted. Second, in the late Miocene (about 7.5 Ma), subaerial speleothems were being deposited in the cave under humid climate conditions. Third, post-Miocene, the cave enlarged and modified at and above the water level by likely warm, sulfuric water. Fourth, water levels dropped and speleothems were deposited again during later humid climate conditions.","PeriodicalId":50244,"journal":{"name":"Journal of Cave and Karst Studies","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2022-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90923668","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Joshua B. Mouser, David Ashley, Douglas Zentner, Shannon Brewer
Cave crayfishes are important members of groundwater communities, but many cave crayfishes are threatened or endangered. Unfortunately, we lack basic life history and ecological data that are needed for developing conservation plans for most cave crayfishes, especially the role of seasonal and annual fluctuations in structuring populations. Therefore, we determined the seasonal life history and habitat use of Cambarus setosus in Smallin Civil War Cave, Christian County, Missouri, United States. We conducted visual crayfish surveys over a 400 m section of the cave from 2006 to 2019. We used multinomial logit, multiple linear regression, and logistic regression models to estimate crayfish substrate, water depth, and water velocity use, respectively. All models included sex, carapace length, season, distance into the cave, and interactions between all variables and sex as predictor terms. We also used t-tests to assess morphometric differences between male and female crayfish. Six mark-recapture events (2010 to 2019) were used to estimate population sizes using a nil-recapture model. We attempted to age eight individuals using gastric mill bands, but annual bands were not discernable. We found reproductively active males during all seasons. We captured one ovigerous female during the spring, though ovigerous females were observed during show cave tours during spring, summer, and autumn. Male C. setosus were more likely to use homogenous and heterogeneous rock substrates and shallower and calmer water when compared to females; however, these relationships varied based on distance into the cave and season. Females sampled were significantly larger than males, and males regenerated chelae more often. Minimum population size estimates ranged from 9 to 159 individuals and indicated the population was relatively stable. Our data provide both a baseline population estimate for comparison with future studies and valuable trait information that is often lacking but useful for developing conservation efforts.
洞穴小龙虾是地下水群落的重要成员，但许多洞穴小龙虾受到威胁或濒临灭绝。不幸的是，我们缺乏为大多数洞穴小龙虾制定保护计划所需的基本生活史和生态数据，特别是季节性和年度波动在结构种群中的作用。因此，我们在美国密苏里州克里斯蒂安县的斯莫林内战洞穴(Smallin Civil War Cave)测定了Cambarus setosus的季节性生活史和栖息地利用。从2006年到2019年，我们对洞穴400米长的区域进行了视觉小龙虾调查。我们分别使用多项logit、多元线性回归和逻辑回归模型来估计小龙虾的基质、水深和水速度的利用。所有的模型都包括性别、甲壳长度、季节、进入洞穴的距离，以及所有变量和性别之间的相互作用。我们还使用t检验来评估雄性和雌性小龙虾之间的形态计量差异。6个标记-再捕获事件(2010年至2019年)用于使用零再捕获模型估计种群规模。我们尝试使用胃磨带对8个个体进行年龄测定，但年际带无法识别。我们发现一年四季都有繁殖活跃的雄性。我们在春季捕获了一只羽绒服的雌性，尽管在春季，夏季和秋季的洞穴参观中观察到了羽绒服的雌性。与雌性相比，雄性固固螺更倾向于使用均质和非均质岩石基质和更浅、更平静的水;然而，这些关系根据进入洞穴的距离和季节而变化。雌虫明显大于雄虫，且雄虫再生螯体的频率更高。最小种群规模估计在9 ~ 159只之间，表明种群相对稳定。我们的数据提供了与未来研究比较的基线种群估计和有价值的性状信息，这些信息通常缺乏，但对发展保护工作有用。
{"title":"Seasonal context of Bristly Cave Crayfish Cambarus setosus habitat use and life history","authors":"Joshua B. Mouser, David Ashley, Douglas Zentner, Shannon Brewer","doi":"10.4311/2021lsc0110","DOIUrl":"https://doi.org/10.4311/2021lsc0110","url":null,"abstract":"Cave crayfishes are important members of groundwater communities, but many cave crayfishes are threatened or endangered. Unfortunately, we lack basic life history and ecological data that are needed for developing conservation plans for most cave crayfishes, especially the role of seasonal and annual fluctuations in structuring populations. Therefore, we determined the seasonal life history and habitat use of Cambarus setosus in Smallin Civil War Cave, Christian County, Missouri, United States. We conducted visual crayfish surveys over a 400 m section of the cave from 2006 to 2019. We used multinomial logit, multiple linear regression, and logistic regression models to estimate crayfish substrate, water depth, and water velocity use, respectively. All models included sex, carapace length, season, distance into the cave, and interactions between all variables and sex as predictor terms. We also used t-tests to assess morphometric differences between male and female crayfish. Six mark-recapture events (2010 to 2019) were used to estimate population sizes using a nil-recapture model. We attempted to age eight individuals using gastric mill bands, but annual bands were not discernable. We found reproductively active males during all seasons. We captured one ovigerous female during the spring, though ovigerous females were observed during show cave tours during spring, summer, and autumn. Male C. setosus were more likely to use homogenous and heterogeneous rock substrates and shallower and calmer water when compared to females; however, these relationships varied based on distance into the cave and season. Females sampled were significantly larger than males, and males regenerated chelae more often. Minimum population size estimates ranged from 9 to 159 individuals and indicated the population was relatively stable. Our data provide both a baseline population estimate for comparison with future studies and valuable trait information that is often lacking but useful for developing conservation efforts.","PeriodicalId":50244,"journal":{"name":"Journal of Cave and Karst Studies","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2022-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78207454","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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