A New Blind Cave Fish Population of Genus Astyanax: Geography, Morphology and Behavior

A new population of blind, cave dwelling tetra fish of the genus Astyanax was discovered in Granadas Cave, in the Balsas drainage, southern México. All blind Mexican tetras previously described are from Tampico and San Luis Potosí, northern México. The discovery of a new blind morph thus represents an independent colonization and convergent adaptation to the cave environment by this fish. Individuals of this population display variability of their troglomorphic features. Some individuals presented asymmetrical degeneration of the eyes, where one was normal, but the other somewhat reduced in size and complexity. Loss of pigmentation and eye reduction, although sometimes correlated, were not always linked; reduced eyes were found on pigmented fish and unpigmented fish often possessed normal eyes. Some individuals had reduced lens size or an absence of lens altogether. Retina is highly modified with photoreceptors sometimes absent. Eye reduction was correlated with a diminished size of the optic lobes and an increase of the prosencephalon. Modifications of the skull involve closing in of the circumorbital series of bones. Certain aspects of behavior are also modified.     

Hickmania Troglodytes, the Tasmanian Cave Spider, and its Potential Role in Cave Management

Cave faunas – which often contain a high representation of spiders – are subject to increasing pressure from the effects of epigean habitat degradation and recreational caving activities. Hickmania troglodytes is a prominent member of the Tasmanian cave fauna, a spider of phylogenetic, zoogeographic and ecological importance, but about which little has previously been known. Long-term monitoring has revealed many unusual life-cycle characteristics in this species, most of which occur over long periods of time and are dependent upon environmental stability. The species presents a potentially useful tool in the management and monitoring of cave fauna and karst, as it is large, conspicuous, numerous, ubiquitous, sedentary, functionally significant and potentially sensitive to various sources of disturbance. H. troglodytes may provide a visible and obvious measure of disturbance in and around cave entrances, and may also prove useful in detecting broader scale impacts affecting the entire cave. Many promising developments are being made in terms of cave management in Tasmania, but other issues are less well addressed and still need to be resolved. With further research, the use of indicator or sentinel species may prove to be well suited to the less complex and often sparsely populated subterranean environment, and may play an important role within larger management strategies for cave fauna and karst.     

Genetic Relatedness and Variability in Inbred and Wild Populations of the Solitary Ascidian Ciona intestinalis Revealed by Arbitrarily Primed Polymerase Chain Reaction

As the first step in the establishment of inbred Ciona intestinalis strains, the genetic backgrounds of several local populations were evaluated on the basis of comparing 313 random amplified polymorphic DNA (RAPD) loci. Cluster analyses of individuals indicated that this species has local genetic characteristics, although various genetic distances among the populations were relatively low. The bulked RAPD analyses revealed that populations from Torihama and from Onagawa were the most distantly related among the 7 populations examined, suggesting that these two populations are the best candidates for outbreeding. Successive inbreeding in the laboratory was achieved using the Onagawa population. Although the genetic similarity of the F₄ progeny became distinctly higher than that of natural populations, F₅ progeny did not survive, presumably owing to homozygous lethal alleles. Received October 15, 1999; accepted July 18, 2000.     

Mexican Fruit Fly Populations in the Semi-Arid Highlands of the Sierra Madre Oriental in Northeastern Mexico

The Mexican fruit fly, Anastrepha ludens Loew (Diptera: Tephritidae), is one of the most important pests of citrus in Mexico. We report the results of an analysis of A. ludens populations that inhabit the semi-arid highlands of the Sierra Madre Oriental in northeastern Mexico. This study aimed to provide information on population fluctuation of A. ludens and how it relates to climate variables, as well as insights into habitat and native parasitoids. Population peaked in the period July–November when ripe fruits of the wild host, Casimiroa pubescens Ramírez, were available. No adults were captured the rest of the year, suggesting that high populations depend on the availability of wild host fruit. No significant relationships between population fluctuation and climatic variables were observed, except for minimum temperature. Fruit samples of citron (Citrus medica L.), pomegranate (Punica granatum L.), and C. pubescens were collected to determine degree of infestation. Infestation levels (pupae/g) ranged between 0.0006 for citron, 0.0047 for pomegranate, and 0.0240 for C. pubescens. A native parasitoid of Tephritidae, Doryctobracon crawfordii (Viereck) (Braconidae), was identified. Parasitism percentage was calculated at 12.5% on C. pubescens fruits. No parasitoids were observed on citron or pomegranate fruit samples. These results contribute to knowledge on behavior of A. ludens native to temperate environments where no commercial hosts are available. Further research on host expansion of this pest in light of scenarios of global climate change is suggested.     

The Laterosensory Canal System in Epigean and Subterranean Ituglanis (Siluriformes: Trichomycteridae), With Comments About Troglomorphism and the Phylogeny of the Genus

The laterosensory system is a mechanosensory modality involved in many aspects of fish biology and behavior. Laterosensory perception may be crucial for individual survival, especially in habitats where other sensory modalities are generally useless, such as the permanently aphotic subterranean environment. In the present study, we describe the laterosensory canal system of epigean and subterranean species of the genus Ituglanis (Siluriformes: Trichomycteridae). With seven independent colonizations of the subterranean environment in a limited geographical range coupled with a high diversity of epigean forms, the genus is an excellent model for the study of morphological specialization to hypogean life. The comparison between epigean and subterranean species reveals a trend toward reduction of the laterosensory canal system in the subterranean species, coupled with higher intraspecific variability and asymmetry. This trend is mirrored in other subterranean fishes and in species living in different confined spaces, like the interstitial environment. Therefore, we propose that the reduction of the laterosensory canal system should be regarded as a troglomorphic (= cave‐related) character for subterranean fishes. We also comment about the patterns of the laterosensory canal system in trichomycterids and use the diversity of this system among species of Ituglanis to infer phylogenetic relationships within the genus. J. Morphol. 278:4–28, 2017. ©© 2016 Wiley Periodicals,Inc.     

The cell types in the adenohypophysis of the Blind Mexican Cave Fish,Anoptichthys jordani (Hubbs and Innes)

Summary Staining sagittal sections of the pituitary of the Blind Mexican Cave Fish, Anoptichthys jordani, with a number of methods including Herlant's tetrachrome, Herlant's Alcian Blue (AB)-periodic acid Schiff (PAS)-orange G, Gabe's aldehyde fuchsin and lead hematoxylin according to Mac Conaill, made it possible to distinguish seven tinctorial cell types in the adenohypophysis: in the pro-adenohypophysis erythrosin-positive acidophils, and lead hematoxylin-positive amphiphils, lining branches of the neural lobe; in the meso-adenohypophysis orange G-positive acidophils, large, weakly AB- and AF-positive, strongly PAS- positive basophils, and smaller strongly AB- and AF-positive basophils; in the metaadenohypophysis lead hematoxylin-positive and -negative cells. These cell types are compared with those in other teleosts.This work was supported by a grant from the Netherlands Organization for the Advancement of Pure Research (Z. W. O.).The author gratefully acknowledges the constant interest and helpful suggestions of Prof. Dr. P. G. W. J. van Oordt. Thanks are also due to Mr. H. van Kooten for making the photographs.     

河南织机洞旧石器遗址的洞穴堆积和沉积环境分析

MIS3阶段晚期是末次冰期中一个气候比较温暖的间冰阶,当时人类活动相当活跃,在世界各地这一时期的人类文化遗址不仅数量多,而且文化面貌也发生明显的变化。织机洞遗址是一处以旧石器时代中晚期为主的洞穴遗址,洞穴中堆积地层可以划分为四层:下部含丰富的打制石器称下文化层,属旧石器中晚期;中部不含石器;上部含少量打制石器称中文化层,属旧石器晚期;顶部含有裴李岗和秦汉时期的文化遗存称上文化层,属全新世时期。根据光释光年代测定,文化遗存最为丰富的下文化层,年龄为距今3·5—5万年,相当于MIS3阶段的中晚期,正处于"旧石器晚期革命"的前夕。孢粉分析结果表明,下文化层所处的MIS3阶段气候比较温暖湿润,为暖温带草原-疏树草原环境,良好的气候环境有利于当时古代人类的生存与繁衍。     

Convergent evolution of the cavefish Astyanax (Characidae, Teleostei): genetic evidence from reduced eye-size and pigmentation

More than 20 populations of the cave-dwelling characid Astyanax occur within a restricted karst area in Mexico. The fish possess reduced eyes without lenses and visual cells. It is still an open question as to whether this condition evolved convergently after multiple entries of the surface ancestor into the different caves or whether a single cave ancestor, already characterized by reduced eyes, spread secondarily within them. In the crosses between specific populations, specimens appear that deviate considerably from those of the parents. They possess larger and better-developed eyes with histologically intact lenses and visual cells; they thus have the structural potential for vision. This indicates that in different cave populations, different mutations in the eye gene system have occurred. In cases where these non-functional rudimentary genes are recombined in hybrid specimens, gene expression may be restored. This is the result of separate evolution of several Astyanax cave populations.  © 2003 The Linnean Society of London, Biological Journal of the Linnean Society, 2003, 80 , 545−554.     

The Occurrence of Fungi in the Recently Discovered Jarkowicka Cave in the Karkonosze Mts. (Poland)

Our study is one of the very few cases of speleomycological research in recently discovered caves. The aim of this research was to assess the population size of fungal colonies and their species composition in the Jarkowicka cave, discovered in 2012. The air samples were taken from one location outside the cave and from two locations inside of it. Mycological evaluation of the rocks inside the cave was performed usingswab sampling procedure. In the Jarkowicka cave we found 22 species of fungi, including 13 isolated from air at the entrance and from the walls, and 8 species from air inside the cave. Cladosporium spp. were the fungi most frequently isolated from internal atmosphere of the Jarkowicka cave, and from the external air. On the other hand, the fungi most frequently isolated from the rocks were Mucor spp. We found several species not yet described as cave inhabitants: Hypocrea pachybasioides, Cladosporium uredinicola, and Embellisia abundans. Our study may provide a basis for comparison to other similar studies conducted in frequently visited caves by tourists.     

The sensory basis of rheotaxis in the blind Mexican cave fish, Astyanax fasciatus

The sensory basis of rheotaxis (orientation to currents) was investigated in the blind Mexican cave fish, Astyanax fasciatus. An unconditioned rheotactic response to uniform velocity flows was exhibited, with a threshold of less than 3 cm s⁻¹. Disabling the entire lateral line or the superficial neuromast receptor class increased the rheotactic threshold to greater than 9 cm s⁻¹. A pharmacological block of the lateral line canal system alone had no effect. These results demonstrate that the superficial lateral line system controls rheotaxis at low current velocities. The effect of pairing an odor stimulant with the water current dropped the rheotactic threshold to less than 0.4 cm s⁻¹. This study provides a clear behavioral role for the superficial neuromasts where none previously existed, and also establishes a link between the mechanosensory lateral line and olfactory systems in the olfactory search behavior of the cave fish. Accepted: 9 January 1999     

Molecular Phylogenetic Analysis of Archaea and Bacteria in Wind Cave,South Dakota

The diversity of bacteria and archaea was characterized from sediments collected from Wind Cave located in Wind Cave National Park in the Black Hills of South Dakota. Wind Cave is a limestone dissolution cave with strata that started forming over 300 million years ago, making it one of the oldest in the world. Previous work suggested that the cave was largely a detritus based system ultimately dependent upon allochthonous energy and carbon from photosynthesis of the overlying vegetation, and algae growing near lights along the tour routes. In this work, we used a molecular phylogenetic approach to characterize the microbial structure and infer a corresponding ecosystem function where appropriate. Four bacterial divisions and subdivisions were found in the culture collection, which represented 14 phylotypes, whereas 12 divisions and subdivisions were identified in the clonal analysis comprising 49 phylotypes. The predominant groups were the γ-Proteobacteria and Acidobacteria. Although a few of the clones resembled sequences from other cave and subterranean systems, no cave-specific bacterial community was evident in this work. Archaeal phylotypes (20 Crenarchaeota and 2 Euryarchaeota) were detected, with a large proportion of the Crenarchaeota resembling sequences from a South African gold mine. One archaeal cluster in particular appears to be specific to the subterranean environment. Most of the microbial sequences were not related to known chemolithoautotrophs, therefore we conclude that this particular community is likely detritus based where allochthonous energy and carbon are transported into the cave by infiltrating waters.     

Colonization and turnover of Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis in otitis-prone children

Recurrent otitis media are frequently intractable during childhood. It is unclear whether recurrent otitis media is caused by etiological bacteria colonization or by new infections. Streptococcus pneumoniae, Haemophilus influenzae and Moraxella catarrhalis were isolated from the nasopharynx of 7 otitisprone and 2 non-prone children with recurrent otitis media. Plural bacterial species and strains were found in all children while affected by otitis media. The same strain was repeatedly isolated from all otitisprone children even after administration of antibiotics but was not from the non-prone children. Antibiotic susceptibility did not differ significantly among the same repeatedly isolated strains. This pilot study suggests that the etiological bacteria tend to colonize and is hard to eliminate in otitis-prone children.     

广西布兵盆地么会洞发现的巨猿牙齿化石

对广西布兵盆地么会洞发现的哺乳动物化石的研究显示,该地点的部分高等灵长类牙齿化石中,16枚可归入巨猿步氏种(Gigantopithecus blacki),其形态特征与中国、越南和印度北部发现的巨猿化石相似。在尺寸大小上与重庆巫山和广西柳城巨猿洞的相近,暗示么会洞巨猿的时代与之接近,且共生的哺乳动物群也非常相似,指示它们之间相近的生物地层年龄。古地磁分析结果显示其时代在奥都威正极性世。     

洛南花石浪龙牙洞1995年出土石制品的拼合研究

本文是对洛南花石浪龙牙洞遗址洞内部分1995年发掘出土的18608件石制品的拼合研究结果。在纳入研究的18499件标本中(不含石料、石锤、石砧和烧石等标本108件)共获得94个拼合组,涉及212件石制品,拼合率约1．15％。分析结果显示拼合研究不但可以帮助我们更深刻地理解龙牙洞遗址石制品的平面及垂直分布规律,还是准确地判断遗址埋藏过程的有效手段。拼合研究在恢复早期人类石器制作技术上具有独到的优势,石核—石片拼合组合以及石片之间的拼合关系可以更清楚地显示早期人类所采用的剥片技术,但以拼合石制品在洞穴中的分布距离判断具体的剥片方法有局限性。     

Populations and production of bacteria in the plankton of two shallow lakes

The troglobitic amphipod crustacean Crangonyx antennatus populates two distinct habitats in southern Appalachian caves, mud-bottom pools and gravel-bottom streams. An investigation was conducted to determine if stream populations possess behavioral adaptations to lotic conditions. Observations on the thigmotactic behavior of C. antennatus were made seasonally in six Lee Co., Virginia caves, three containing pool habitats and three with stream habitats. Stream-dwelling amphipods were found to exhibit more cryptic behavior than those inhabiting pools under natural conditions and when disturbed. Artificial stream experiments indicate that stream-dwelling C. antennatus are better adapted behaviorally to lotic conditions than pool-dwelling amphipods.     

Comparative ultrastructural investigations of the pineal organ of the blind cave fish,Anoptichthys jordani,and its ancestor,the eyed river fish,Astyanax mexicanus

A comparative ultrastructural study has been made of the pineal organ in specimens of two closely related populations of the characid fish, Astyanaz mexicanus. The specimens of one population are living in the river, under natural light conditions. The specimens of the other population, originally described as Anoptichthys jordani, are living in a completely dark cave. In specimens of both populations the pineal organ consists of a spindle shaped end-vesicle, connected to the diencephalic roof by a slender stalk. The pineal tissue is compact and consists predominantly of glia-like supporting cells and sensory cells resembling the photoreceptor cells of the lateral vertebrate eye. Phagocytotic microglia-like cells can be found in close contact with the outer segments of the sensory cells. Nerve cells are located in the neighbourhood of neuropil formations, in which synaptic contacts are established between sensory cells and nerve cells. From these nerve cells fibers are emerging, forming the pineal tract that runs down the pineal stalk towards the diencephalon. On the basis of the ultrastructure described by other authors it is concluded that the pineal organ in specimens of the river population of Astyanax mexicanus resembles the pineal organ of other fish species. In specimens of the river population, reared under normal light-dark conditions for 3, 9 or 18 months, conspicuous morphological changes have not been detected in the presumably light-sensitive outer segments of the sensory cells or in other parts of the pineal tissue. In specimens of the cave populations, reared under identical conditions, an age-dependent, gradual regression of the regular outer segment organization of the pineal sensory cells takes place. In other parts of the pineal tissue, only small morphological changes can be observed. In specimens of the cave population, reared in constant darkness, the regression of the pineal outer segment organization begins earlier and is obvious. It is postulated that the gradual age-dependent regression of the regular organization of the outer segments in the pineal organ of cave specimens of Astyanax mexicanus is genetically determined and indicates a regressive evolution of the pineal light sensitivity. The expression of the regressive traits is dependent on the environmental light conditions.     

Random Amplified Polymorphic DNA Diversity among Surface and Subterranean Populations of Asellus aquaticus (Crustacea: Isopoda)

The ecological and evolutionary processes leading to isolation and adaptation of cave animals compared to their surface ancestors are not yet unequivocally understood. In this study the genetic relations of four cave and three surface population of the freshwater crustacean Asellus aquaticus in the Karst region of SW Slovenia and NE Italy were assessed using RAPDs as genetic markers. The results suggest that specialized populations from two caves invaded their subterranean habitat independently, and that their morphological similarity is a result of convergent evolution. Another, less specialized cave population seems to originate from a later colonization of a cave system already inhabited by a more specialized population, but the two populations do not interbreed. This series of temporally and spatially independent invasions has generated a diversity hotspot of non-interbreeding populations of a ubiquitous freshwatercrustacean, which is uniform over most of its range. Genetic variability estimated by the percentage of polymorphic RAPD fragments was similar (86–91%) in most cave and surface populations. Substantially lower values (as low as 49%) were found in two cave populations affected by heavy pollution. Two a priori groupings of populations, traditional subspecies and hydrologically connected groups, were rejected as not significant by means of nested analysis of molecular variance (AMOVA). On the other hand, groupings revealed by UPGMA clustering displayed a significant component of among-group variance. An analysis of gene flow between populations using estimated migration rates confirmed these findings.     

Sensory System Affects Orientational Strategy in a Short-Range Spatial Task in Blind and Eyed Morphs of the Fish, Astyanax fasciatus

In the concerted effort to discover the mechanisms that animals use to orient through space, little attention has been given to the role of the sensory system on shaping orientational strategy. This study tests whether animals with different sensory systems use different mechanisms to orient. The characin fish Astyanax fasciatus (Cuvier, 1819) exists in two morphs in the same species – a number of populations of blind cave fish that rely on their lateral line to gain fine-scale information from their surroundings, and eyed surface populations that can also use visual cues. Both forms of the species were trained to orient to a goal signalled by landmarks and by egocentrically based cues (turn left or right) in a T-maze. When these cues were placed in conflict by switching the landmark position, only the eyed fish used the landmarks to orient, reflecting a difference in the way that the two sensory systems of these animals operate. Our results have implications for the evolution of the mechanisms of orientation, suggesting that these mechanisms may be constrained by the sensory cues that are available and hence the type of information that animals are able to glean from their surroundings.     

Genetic diversity and dispersal of the moss Sarconeurum glaciale on Ross Island, East Antarctica

The extent of genetic variation and dispersal mechanisms were investigated over short distances of 1–100 m, and up to 3 km, by the random amplified polymorphic DNA (RAPD) technique, for the moss Sarconeurum glaciale , at three locations on Ross Island, Antarctica. At Arrival Heights, genetic variation occurred within single colonies, and the relationships between clumps indicated that they were dispersed down small, meltwater drainage channels by water. The genetic similarities between the colonies from Arrival Heights and others from Scott Base and Crater Hill, a few km away, together with the prevailing wind direction and absence of this moss in the intervening snow-covered area, suggested longer-distance dispersal by wind. Overall, the Ross Island samples appeared to form a single, polymorphic population that was distinct from another population at Canada Glacier, 110 km distant. Somatic mutation, rather than immigration of genetically different propagules from elsewhere, appeared to be the most probable cause of genetic variability in these haploid, vegetatively reproducing Antarctic moss populations. Initiation of recolonization of S. glaciale across a dirt track at Arrival Heights was also investigated by RAPDs, to investigate how regrowth of mosses in disturbed areas occurred in the extreme environment of Antarctica.