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.     

Morphometric analysis of interspecific and microgeographic variation of crayfish from a Mexican cave

Two undescribed species of Procambarus crayfish (Crustacea, Decapoda) inhabit the subterranean stream running in the recently explored Cueva de Los Camarones, Chiapas, Mexico. Individuals ranging from dark, robust, large-eyed forms with an epigean mien to pale, comparatively slender, microphthalmic ones resembling related troglobites were found, but only the extremes could be distinguished visually. Evolutionary relationships among individuals were investigated morphometrically by means of multivariate analysis'on 14 body dimensions. These analyses revealed a significant discontinuity between the two species, mainly determined by the shape of the rostrum, chelae and telson. The occurrence of a few aberrant phenotypes may indicate the existence of some gene flow between the two species.
Microgeographic variation was demonstrated within the less cavernicolous species. The characters involved were the same as those that discriminate between the two species. These results are compared with allozymic data presented in a parallel paper and the role of genie introgression and environmental induction are discussed.     

Postcranial variations in late Epigravettian and Neolithic human remains from Arene Candide cave (Liguria,Italy)

Late Epigravettian postcranial human remains from the Arene Candide cave (Finale Ligure, Savona, Italy) were compared with the Neolithic sample found in the upper levels of the same site. Data on length, diaphyseal circumference and diameter of clavicle, humerus, radius, femur and tibia were collected from male specimens having all these bones. The Epigravettian sample is characterized by significantly greater tibial length, robustness and platycnemia, significantly lower circumferences in the upper limb bones and the clavicle, and a high degree of asymmetry. Variations observed in lower limb bones are those expected on the basis of the different functional requirements of a hunting and gathering economy compared to a more sedentary, food producing economy. Differences in the upper limb bones and the clavicle are less explicable. However, considering that in spite of a more slender structure, the Epigravettian bones show evidence of vigorous use, variation in upper limb could result from qualitatively different involvements.     

中国喀斯特地区微生物群落结构和功能的研究进展

频繁的人类生产活动使植被遭到破坏,造成基岩裸露的石漠化现象,严重制约了喀斯特地区自然和社会经济的发展,随着生态修复工程的大力开展,微生物群落的结构和功能在生态修复中逐渐受到重视,因为微生物作为喀斯特生态系统的重要组成部分,不仅在物质循环过程中起着重要作用,也在喀斯特生态系统修复中占有十分重要的地位。所以微生物群落结构和功能的研究可以作为衡量生态系统稳定性的重要指标。就中国喀斯特地区的典型植被恢复的不同阶段、成土过程、不同的土地利用方式、矿山修复过程以及不同水域中的微生物群落结构及功能等方面的研究状况进行系统梳理,结合实例综合论述喀斯特地区生态修复过程中微生物作用的研究进展,以期为喀斯特地区生态修复提供参考。     

基于地表水与地下水分割校正的漓江流域水供给服务时空格局研究

喀斯特区域水循环过程与其他地区存在显著区别,其水供给服务也具有独特的空间分布特征。然而,目前针对喀斯特地区产水量的时空变化研究较少考虑喀斯特生态系统的特殊性,导致产水量的空间模拟结果存在一定偏差。根据喀斯特地貌形态和地下水补径排泄特征提出了一种产水量分割方法,并基于水量平衡原理建立了地表水与地下水分割校正概念模型。选取喀斯特山区典型区域漓江流域为研究区,通过上述方法校正了InVEST模型产水量模拟结果,从栅格、地貌分区和子流域3个尺度分析了漓江流域2000—2020年产水量校正前与校正后时空分布格局。研究结果表明：(1)漓江流域2000—2020年InVEST模型产水量呈现先减后增再减的趋势,水供给服务空间分布格局为北高南低。产水深度在岩溶区和非岩溶区几乎没有差异,但在岩溶区内部差异明显：裸露型岩溶区产水深度高于覆盖型和埋藏型,峰林平原产水深度高于峰丛洼地。子流域分区平均产水深度排序为漓江上游区>漓江中游区>恭城河区>荔浦河区>漓江下游区。(2)利用地表与地下水分割校正后,水供给服务空间分布格局为四周高于中部,西北部高于东南部。非岩溶区产水深度明显高于岩溶区,埋...     

云南省耿马佛洞地遗址发掘简报

佛洞地遗址位于云南省临沧市耿马傣族佤族自治县勐简乡勐简村大军赛村民小组燕子洞,坐落于一处东南开口的二叠纪灰岩穿洞,南临南汀河。2016～2017年,临沧市文物管理所在公路考古调勘期间发现该遗址;为进一步认识滇西地区旧石器时代晚期文化,2017～2018年对该遗址开展考古发掘工作。发掘区域位于洞内第四台面到第五台面间,共发掘20 m²,出土了包括石制品、动植物化石等在内的大量遗物。初步地层年代学分析显示,遗址时代为距今18400～14000年,共包含3期连续文化,文化遗物以石制品为主,总数达到9735件。佛洞地遗址作为一处热带-亚热带生境下的史前遗址,为我们构建旧石器时代晚期滇西地区文化序列、探讨特定自然生态背景下史前人类的文化适应提供了重要参考。     

中国洞穴盲虾一新种(十足目:匙指虾科)

本文记述采自广西桂林洞穴中的盲米虾属一新种,半盲米虾Ｔｙｐｈｌｏｃａｒｉｄｉｎａｓｅｍｉｔｙｐｈｌａｔａｓｐ．ｎｏｖ．,新种眼角膜色素未完全退化,额剑上下缘均具齿。     

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.     

A narrow hybrid zone between two crayfish species from a Mexican cave

In Northern Chiapas (Mexico), two newly discovered species of Procambarus crayfish inhabit a subterranean stream. These species can be morphologically distinguished only by comparing extreme phenotypes (dark, thick-eyed, surface dwelling-like individuals vs light, elongated, microphtalmic, cave dwelling-like individuals). Individuals with intermediate phenotypes co-occur with those exhibiting extreme phenotypes. Crayfish were assayed electrophoretically and individual patterns at 23 gene loci were obtained. Unusually high levels of heterozygosity in both species and a clear discrimination between the two gene pools were revealed. The relationships between individuals were investigated by means of multivariate analysis on individual multilocus genotype profiles. Results showed the occurrence of individuals genetically intermediate between the two major clusters, which shared allozymic variants with both species. Due to the occurrence of alternative alleles in the two gene pools, we could quantify patterns of introgression, which revealed asymmetric gene flow between the two species. Moreover, differential levels of introgression in subsamples within the surface-like species were found: most introgressed individuals came from the inner section of the cave, where the two species were greatly mixed. These results are also discussed in reference to the morphometric results from a companion paper. A possible evolutionary pathway, leading to the situation in this cave, and possibly in neighbouring cave systems, is outlined. The hypothesis of a past history of allopatric divergence from a common ancestor and a subsequent secondary contact between these two Procambarus species is supported by geological studies. Crayfish sympatry and competitive exclusion are also discussed.