中国贵州省穴居盲鳅一新种(鲤形目,爬鳅科)

记述了采集于贵州省荔波县佳荣镇水井湾溶洞(25°28’N,108°06’E)适应洞穴环境的鳅类1新种:佳荣盲高原鳅Triplophysa jiarongensis sp.nov.。新种与之前记录的7种分布于西江水系的高原鳅(阿庐高原鳅、个旧盲高原鳅、长须盲高原鳅、巨头高原鳅、邱北盲高原鳅、石林盲高原鳅和天峨高原鳅)同属典型洞穴鱼类,都具有一系列与洞穴环境有关的适应性特征。新种与本属其它种类的区别主要为:胸鳍长,后伸达腹鳍起点;尾鳍微凹形;体表色素退化,光滑裸露无鳞;背鳍截形,起点位于腹鳍起点略后方;腹鳍后伸盖过泄殖孔;臀鳍截形;尾柄上下缘存在脂状鳍褶;背鳍分支鳍条8;臀鳍分支鳍条6;胸鳍分支鳍条11;脊椎骨总数4+34;眼完全退化,外观无痕迹;鳔前室被骨质鳔囊包裹,后室发达膨大呈游离膜质鳔。此外还介绍了其栖息地概况和部分生态学信息。     

Quantitative Lipidomics and Spatial MS-Imaging Uncovered Neurological and Systemic Lipid Metabolic Pathways Underlying Troglomorphic Adaptations in Cave-Dwelling Fish

Sinocyclocheilus represents a rare, freshwater teleost genus endemic to China that comprises the river-dwelling surface fish and the cave-dwelling cavefish. Using a combinatorial approach of quantitative lipidomics and mass-spectrometry imaging (MSI), we demonstrated that neural compartmentalization of lipid distribution and lipid metabolism is associated with the evolution of troglomorphic traits in Sinocyclocheilus. Attenuated docosahexaenoic acid (DHA) biosynthesis via the Δ4 desaturase pathway led to reductions in DHA-phospholipids in cavefish cerebellum. Instead, cavefish accumulates arachidonic acid-phospholipids that may disfavor retinotectal arbor growth. Importantly, MSI of sulfatides coupled with immunostaining of myelin basic protein and transmission electron microscopy images of hindbrain axons revealed demyelination in cavefish raphe serotonergic neurons. Demyelination in cavefish parallels the loss of neuroplasticity governing social behavior such as aggressive dominance. Outside the brain, quantitative lipidomics and qRT-PCR revealed systemic reductions in membrane esterified DHAs in the liver, attributed to suppression of genes along the Sprecher pathway (elovl2, elovl5, and acox1). Development of fatty livers was observed in cavefish; likely mediated by an impeded mobilization of storage lipids, as evident in the diminished expressions of pnpla2, lipea, lipeb, dagla, and mgll; and suppressed β-oxidation of fatty acyls via both mitochondria and peroxisomes as reflected in the reduced expressions of cpt1ab, hadhaa, cpt2, decr1, and acox1. These neurological and systemic metabolic adaptations serve to reduce energy expenditure, forming the basis of recessive evolution that eliminates nonessential morphological and behavioral traits and giving cavefish a selective advantage to thrive in caves where proper resource allocation becomes a major determinant of survival.     

广西盲鱼一新种及其系统关系分析(鲤形目:鲤科:鲃亚科)

经鉴定,采自广西天峨县溶洞的盲鱼为金线鲃属一新种,依形态特征命名为叉背金线Ｓｉｎｏｃｙｌｏｃｈｅｉｌｕｓ　ｆｕｒｃｏｄｏｒｓａｌｉｓ　ｓｐ． ｎｏｖ．,根据主要特征分析认为：新种适应洞穴环境相关性状特化程度大致与鸭嘴金线鲃相当;新种及其若干近似种的物种形成,是营半穴居生活的类似长须金线鲃的祖先适应辐射的结果。     

Blind cavefish retain functional connectivity in the tectum despite loss of retinal input

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