COMPREHENSIVE ASSESSMENTS OF SPECIES? EXTINCTION RISKS HAVE DOCUMENTED THE EXTINCTION CRISIS1 AND UNDERPINNED STRATEGIES FOR REDUCING THOSE RISKS2. GLOBAL ASSESSMENTS REVEAL THAT, AMONG TETRAPODS, 40.7% OF AMPHIBIANS, 25.4% OF MAMMALS AND 13.6% OF BIRDS ARE THREATENED WITH EXTINCTION3. BECAUSE GLOBAL ASSESSMENTS HAVE BEEN LACKING, REPTILES HAVE BEEN OMITTED FROM CONSERVATION-PRIORITIZATION ANALYSES THAT ENCOMPASS OTHER TETRAPODS4,5,6,7. REPTILES ARE UNUSUALLY DIVERSE IN ARID REGIONS, SUGGESTING THAT THEY MAY HAVE DIFFERENT CONSERVATION NEEDS6. HERE WE PROVIDE A COMPREHENSIVE EXTINCTION-RISK ASSESSMENT OF REPTILES AND SHOW THAT AT LEAST 1,829 OUT OF 10,196?SPECIES (21.1%) ARE THREATENED?CONFIRMING A PREVIOUS EXTRAPOLATION8 AND REPRESENTING 15.6?BILLION YEARS OF PHYLOGENETIC DIVERSITY. REPTILES ARE THREATENED BY THE SAME MAJOR FACTORS THAT THREATEN OTHER TETRAPODS?AGRICULTURE, LOGGING, URBAN DEVELOPMENT AND INVASIVE SPECIES?ALTHOUGH THE THREAT POSED BY CLIMATE CHANGE REMAINS UNCERTAIN. REPTILES INHABITING FORESTS, WHERE THESE THREATS ARE STRONGEST, ARE MORE THREATENED THAN THOSE IN ARID HABITATS, CONTRARY TO OUR PREDICTION. BIRDS, MAMMALS AND AMPHIBIANS ARE UNEXPECTEDLY GOOD SURROGATES FOR THE CONSERVATION OF REPTILES, ALTHOUGH THREATENED REPTILES WITH THE SMALLEST RANGES TEND TO BE ISOLATED FROM OTHER THREATENED TETRAPODS. ALTHOUGH SOME REPTILES?INCLUDING MOST SPECIES OF CROCODILES AND TURTLES?REQUIRE URGENT, TARGETED ACTION TO PREVENT EXTINCTIONS, EFFORTS TO PROTECT OTHER TETRAPODS, SUCH AS HABITAT PRESERVATION AND CONTROL OF TRADE AND INVASIVE SPECIES, WILL PROBABLY ALSO BENEFIT MANY REPTILES.

CLIMATE CHANGE IS PROJECTED TO BE THE MOST EXTENSIVE HUMAN-INDUCED DISTURBANCE TO OCCUR ON NATURAL ECOSYSTEMS, INDUCING CHANGES IN DIFFERENT BIODIVERSITY FEATURES INCLUDING THE EVOLUTIONARY HISTORY OF A REGION THROUGH THE DECLINE AND LOSS OF ITS PHYLOGENETIC DIVERSITY. AMPHIBIANS, GIVEN THEIR ECTOTHERMIC LIFE CYCLE AND CRITICAL CONSERVATION STATUS, WOULD POTENTIALLY BE EXPOSED TO EXTINCTION PROCESSES UNDER CONDITIONS OF CLIMATE CHANGE, WITH THE CORRESPONDING LOSS OF EVOLUTIONARY HISTORY IN REGIONS OF HIGH BIODIVERSITY. THIS RESEARCH ADDRESSES THE EFFECTS OF CLIMATE CHANGE ON THE EVOLUTIONARY HISTORY OF AMPHIBIANS IN THE CHILEAN BIODIVERSITY HOTSPOT, BY ESTIMATING THE PD (PHYLOGENETIC DIVERSITY) AND PE (PHYLOGENETIC ENDEMISM) OF 27 SPECIES. USING DIFFERENT RCP (RCP 4.5 AND 8.5) AND TIME FRAMES (YEARS 2050 AND 2070), WE CREATE SPECIES DISTRIBUTION MODELS (SDM) TO EVALUATE THE SPECIES RANGE DYNAMICS AND THE PHYLODIVERSITY IN THE HOTSPOT. ALSO, GIVEN THAT PROTECTED AREAS (PA) ARE THE MAIN GLOBAL STRATEGY TO ENSURE THE CONSERVATION OF SPECIES AND THEIR FEATURES, WE EVALUATE THE CAPACITY OF PA TO CONSERVE THE EVOLUTIONARY HISTORY IN THE HOTSPOT. OUR RESULTS SHOW A SET OF MODELED SPECIES THAT WILL BECOME EXTINCT, OR WILL EXPERIMENT CHANGES IN THEIR DISTRIBUTIONAL RANGES, INDUCING A CLEAR DECLINE OF AMPHIBIAN EVOLUTIONARY HISTORY FOR THE NEXT 30 TO 50 YEARS, AND A WORRYING LOW CAPACITY OF THE PA TO CONTAIN CURRENT AND FUTURE PD AND PE. GIVEN THE CRITICAL AMPHIBIAN SCENARIO, OUR RESULTS HIGHLIGHT THE NEED FOR FURTHER RESEARCH TO IMPROVE THE DECISION-MAKING PROCESS IN THE HOTSPOT AREA ADDRESSING THE POTENTIAL AMPHIBIAN EXTINCTION RISK, THE LACK OF PROTECTION BY THE PA SYSTEM, AND THE LOSS OF EVOLUTIONARY HISTORY AS A KEY ASPECT OF BIODIVERSITY.

THE INTERPRETATION OF THERMAL-GRADIENT DATA DEPENDS ON THE BEHAVIORAL DRIVES REPORTED OR ASSUMED, AND ON THE UNDERLYING BEHAVIORAL MODELS EXPLAINING HOW SUCH DRIVES OPERATE. THE BEST-KNOWN EXAMPLE IS POSITIVE THERMOTAXIS, A THERMOREGULATORY BEHAVIORAL DRIVE FREQUENTLY LINKED TO A DUAL SET-POINT MODEL OF THERMOREGULATION AROUND A TARGET RANGE. THIS BEHAVIORAL DRIVE IS OFTEN ASSUMED AS DOMINANT AMONG ?ECTOTHERMS?, INCLUDING AMPHIBIANS. HOWEVER, WE ARGUE THAT, BECAUSE AMPHIBIANS ARE EXTREMELY DIVERSE, THEY MAY EXHIBIT ALTERNATIVE BEHAVIORAL DRIVES IN THERMAL GRADIENTS, AND TACKLE THIS IDEA FROM TWO PERSPECTIVES. FIRST, WE PROVIDE A HISTORICAL REVIEW OF ORIGINAL DEFINITIONS AND PROPOSED LIMITS FOR INFERENCE. SECOND, ALTHOUGH CAVEATS APPLY, WE PROPOSE THAT A CROSS-STUDY ANALYSIS OF DATA OF TEMPERATURE SETTINGS OF GRADIENTS AND THE TEMPERATURES SELECTED BY AMPHIBIANS WOULD CORROBORATE ALTERNATIVE BEHAVIORAL DRIVES, INCLUDING NEGATIVE THERMOTAXIS. THEREFORE, WE ANALYZED PUBLISHED DATA FOCUSING ON SUCH RELATIONSHIPS AND SHOW THAT GRADIENT TEMPERATURE SETTINGS INFLUENCE THE TEMPERATURES SELECTED BY AMPHIBIANS, WITH FURTHER EFFECTS OF PHYLOGENY AND ONTOGENY. WE CONCLUDE THAT THERMAL GRADIENT EXPERIMENTS ARE OUTSTANDING TOOLS TO INVESTIGATE BEHAVIORAL DRIVES, BUT NO GIVEN DRIVE CAN BE ASSUMED A PRIORI UNLESS ADDITIONAL INFORMATION ABOUT THERMOREGULATION IS AVAILABLE. BASED ON THE HISTORICAL DEBATE, WE PROPOSE USING SELECTED TEMPERATURES AND PREFERRED TEMPERATURES AS DIFFERENT CONCEPTS, THE FORMER MERELY OPERATIONAL AND THE SECOND EXPLICITLY LINKED TO POSITIVE THERMOTAXIS (AND THUS COMPATIBLE WITH DUAL SET-POINT THERMOREGULATION). UNDER THIS VIEW, THERMAL PREFERENCES WOULD STAND FOR A HYPOTHESIS OF A BEHAVIORAL DRIVE (POSITIVE THERMOTAXIS) REQUIRING FORMAL TESTING. THESE CONSIDERATIONS IMPACT THE SCOPE FOR INFERENCE BASED ON THERMAL GRADIENT EXPERIMENTS, PARTICULARLY ECOLOGICAL MODELING AND EMERGING DISEASE.

COMPARATIVE PHYLOGEOGRAPHY DESCRIBES THE PATTERNS OF EVOLUTIONARY DIVERGENCE AND WHETHER OR NOT THEY ARE CONGRUENT, IN CO-DISTRIBUTED POPULATIONS OF DIFFERENT TAXA. IF THE POPULATIONS OF THESE TAXA HAVE BEEN CO-DISTRIBUTED FOR A PROLONGED TIME, AND IF THE TIMES BETWEEN PROCESSES OF PERTURBATION OR VICARIANCE HAVE BEEN MORE OR LESS STABLE, IT IS EXPECTED THAT PATTERNS OF DIVERGENCE WILL BE CONGRUENT IN CLOSELY RELATED SPECIES, FOR EXAMPLE BECAUSE OF SIMILAR BIOLOGICAL AND DEMOGRAPHIC CHARACTERISTICS. LIOLAEMUS PICTUS AND L. CYANOGASTER ARE WIDELY CO-DISTRIBUTED LIZARD SPECIES IN SOUTHERN CHILE, OCCURRING IN A REGION WITH A COMPLEX TOPOLOGY. WE ANALYZED THE PHYLOGEOGRAPHIC STRUCTURE OF THE TWO LIZARD SPECIES USING CYTOCHROME B DNA SEQUENCES TO ESTIMATE THEIR GENETIC STRUCTURE IN RESPONSE TO HISTORICAL EVENTS. OUR RESULTS SUGGEST AN EVOLUTIONARY PATTERN OF GENETIC DIVERSITY FOR EACH SPECIES THAT IS CONSISTENT WITH THE GEOMORPHOLOGICAL HISTORY OF THE REGION, SUGGESTING A COMPLEX PHYLOGEOGRAPHIC HISTORY IN LIOLAEMUS SPECIES. ALSO, THE HIGH LEVELS OF DIVERGENCE AMONG HAPLOTYPES IN SEVERAL POPULATIONS SUGGEST THE POSSIBILITY THAT THEIR ORIGIN MIGHT PREDATE THE MIDDLE PLEISTOCENE IN BOTH SPECIES. FINALLY, OUR RESULTS ARE CONSISTENT WITH OUR HYPOTHESIS THAT TWO SPECIES HAVE RESPONDED TO HISTORICAL EVENTS IN PARALLEL, WHERE HISTORICAL PROCESS HAVE BEEN SUFFICIENT TO INFLUENCE THEIR PHYLOGEOGRAPHICAL STRUCTURE (0.80 CONGRUENCY BETWEEN TOPOLOGIES).

IN THIS WORK, WE UPDATE AND INCREASE KNOWLEDGE ON THE SEVERITY AND EXTENT OF THREATS AFFECTING 57 POPULATIONS OF 46 AMPHIBIAN SPECIES FROM CHILE AND ARGENTINA IN SOUTHERN SOUTH AMERICA. WE ANALYZED THE INTRINSIC CONSERVATION PROBLEMS THAT DIRECTLY IMPACT THESE POPULATIONS. WE SHARED A QUESTIONNAIRE AMONG SPECIALISTS ON THREATS AFFECTING TARGET AMPHIBIAN POPULATIONS WITH INFORMATION ON I) RANGE, II) HISTORICAL OCCURRENCE AND ABUNDANCE, III) POPULATION TRENDS, IV) LOCAL EXTINCTIONS, V) THREATS, AND VI) ONGOING AND NECESSARY CONSERVATION/RESEARCH. WE ASSESSED ASSOCIATION PATTERNS BETWEEN REPORTED THREATS AND POPULATION TRENDS USING MULTIPLE CORRESPONDENCE ANALYSIS. SINCE 2010, 25 OF 57 POPULATIONS HAVE DECLINED, WHILE 16 EXPERIENCED LOCAL EXTINCTIONS. THESE POPULATIONS WERE AFFECTED BY 81% OF THE THREAT CATEGORIES ANALYZED, WITH THOSE RELATED TO AGRICULTURAL ACTIVITIES AND/OR HABITAT MODIFICATIONS BEING THE MOST FREQUENTLY REPORTED. INVASIVE SPECIES, EMERGING DISEASES, AND ACTIVITIES RELATED TO GRAZING, RANCHING, OR FARMING WERE THE THREATS MOST ASSOCIATED WITH POPULATION DECLINES. LOW CONNECTIVITY WAS THE MOST FREQUENT INTRINSIC CONSERVATION PROBLEM AFFECTING 68% OF THE TARGET POPULATIONS, FOLLOWED BY LOW POPULATION NUMBERS, AFFECTING 60%. ONGOING MONITORING ACTIVITY WAS CONDUCTED IN 32 (56%) POPULATIONS AND WAS THE MOST FREQUENT RESEARCH ACTIVITY. THREAT MITIGATION WAS REPORTED IN 27 (47%) POPULATIONS AND WAS THE MOST FREQUENT ONGOING MANAGEMENT ACTIVITY. WE FOUND THAT HABITAT MANAGEMENT IS ONGOING IN 5 (9%) POPULATIONS. AT LEAST 44% OF THE AMPHIBIAN POPULATIONS SURVEYED IN CHILE AND ARGENTINA ARE DECLINING. MORE INFORMATION RELATED TO THE EFFECT OF MANAGEMENT ACTIONS TO RESTORE HABITATS, RECOVER POPULATIONS, AND ELIMINATE THREATS SUCH AS INVASIVE SPECIES IS URGENTLY NEEDED TO REVERSE THE CONSERVATION CRISIS FACING AMPHIBIANS IN THIS NEOTROPICAL REGION.

WE STUDIED HOW FEATURES OF THERMAL RESOURCES AFFECT THE PATTERNS OF ACTIVITY OF PREDATOR (CALLOPISTES MACULATUS) AND ITS PREY (GYRIOSOMUS BATESI AND GYRIOSOMUS SUBRUGATUS) DURING THE PHENOMENON OF THE FLOWERING DESERT IN CHILE. WE PREDICT THAT RESTRICTIONS OR VARIATIONS IN TEMPERATURE AFFECT MAINLY THE ACTIVITY OF INSECTS, AND THAT THIS VARIATION IN THE ACTIVITY OF INSECTS AFFECTS THE PATTERNS OF ACTIVITY OF THE PREDATOR. THE DAILY ACTIVITY OF THE THREE SPECIES WAS BIMODAL, BUT BOTH PREY SPECIES DISAPPEAR WHEN TEMPERATURES EXCEED 40 °C. ACCORDING TO OUR RESULTS, THE PREY ARE THERMOCONFORMERS TO AIR AND SUBSTRATE TEMPERATURE, WHEREAS THE PREDATOR IS A THERMOREGULATOR TO ENVIRONMENTAL CONDITIONS BY THEIR INDEPENDENCE OF AIR AND SUBSTRATE TEMPERATURE.

IN THIS DATA ARTICLE, WE INVESTIGATED THE ACCUMULATION OF HEAVY METALS IN THE LIZARD MICROLOPHUS ATACAMENSIS, IN THREE COASTAL AREAS OF THE ATACAMA DESERT, NORTHERN CHILE. WE CAPTURED LIZARDS IN A NON-INTERVENED AREA (PARQUE NACIONAL PAN DE AZUCAR, PAZ), AN AREA OF MINING IMPACT (CALETA PALITOS, PAL) AND AN ACTIVE INDUSTRIAL ZONE (PUERTO DE CALDERA, CAL).

THE GENUS RADIODISCUS INCLUDES MINUTE TERRESTRIAL SNAILS OCCURRING THROUGHOUT THE AMERICAN CONTINENT. WE ASSESSED THE CONSERVATION STATUS OF EIGHT POORLY KNOWN CHILEAN RADIODISCUS SPECIES USING THE INTERNATIONAL UNION FOR CONSERVATION OF NATURE (IUCN) AND NATURESERVE CATEGORIES AND CRITERIA. UNDER THE IUCN GUIDELINES THE SPECIES WERE ASSESSED USING THE CRITERION B OF GEOGRAPHIC RANGE, WHICH CONSIDERS THE EXTENT OF OCCURRENCE (EOO) AND AREA OF OCCUPANCY (AOO) AS SUBCRITERIA. FOR NATURESERVE WE USED THESE TWO PARAMETERS PLUS THE NUMBER OF OCCURRENCES, ECOLOGICAL VIABILITY, AND THREATS. CONSIDERING SPECIES RARITY AND POSSIBLE SAMPLING BIAS, WE ALSO USED ECOLOGICAL NICHE MODELING TO DETERMINE CLIMATE AND ENVIRONMENTAL TOLERANCES AND PREDICT POTENTIAL SPECIES DISTRIBUTIONS ANALYZING BIOCLIMATIC AND GEOGRAPHICAL LAYERS. RADIODISCUS AUSTRALIS, R. COARCTATUS AND R. QUILLAJICOLA WERE LISTED AS CRITICALLY ENDANGERED BY IUCN AND NATURESERVE STANDARDS; R. COPPINGERI, R. FLAMMULATUS, R. MAGELLANICUS AND R. VILLARRICENSIS AS ENDANGERED BY BOTH METHODS; WHILE R. RIOCHICOENSIS AS ENDANGERED BY IUCN STANDARDS AND VULNERABLE BY NATURESERVE STANDARDS. NICHE MODELING RESULTS INDICATED THAT RADIODISCUS SPECIES RESPOND TO DIFFERENT ENVIRONMENTAL CONDITIONS AND THAT THE PREDICTED DISTRIBUTION AREAS CONTAIN SUITABLE HABITATS BEYOND THE CURRENT RANGES, WHICH MAY BE HELPFUL FOR FUTURE MANAGEMENT PLANS. NATURE-BASED SPORT TOURISM, FORESTRY ACTIVITIES, URBANIZATION, ROADS, POLLUTION, MINING, FOREST FIRES, LIVESTOCK, VOLCANISM, TSUNAMIS, SOIL EROSION AND INTRODUCED SPECIES ARE AMONG THE MAJOR THREATS AFFECTING THESE SNAILS. BASED ON THE LOW NUMBER OF OCCURRENCES AND THE THREATS IDENTIFIED, THE MOST AT-RISK SPECIES ARE R. COARCTATUS AND R. QUILLAJICOLA (ONE RECORD), R. AUSTRALIS (TWO RECORDS) AND R. VILLARRICENSIS (THREE RECORDS); THE LATTER TWO LACKING OCCURRENCES WITHIN PROTECTED AREAS. COMPILING OUR FINDINGS, WE PROPOSE A LIST OF ACTIONS TO PRESERVE CHILEAN RADIODISCUS SPECIES.

MOST ANIMAL GROUPS HAVE SEXUAL DIMORPHISM IN MORPHOLOGICAL CHARACTERS, ESPECIALLY BODY SIZE. IN MANY CASES, SEXUAL DIMORPHISM MAY BE A CONSEQUENCE OF A HIERARCHICAL SOCIAL ORGANIZATION WITHIN POPULATIONS. HOWEVER, POLYGYNY OR MONOGAMY MAY EVOLVE INDEPENDENTLY OF SEXUAL DIMORPHISM. TWO LIOLAEMUS SPECIES ARE KNOWN TO BE GOOD MODEL SPECIES TO STUDY THE RELATIONSHIP BETWEEN SEXUAL DIMORPHISM AND SEXUAL SOCIAL SYSTEM: LIOLAEMUS TENUIS (POLYGYNY) AND LIOLAEMUS COPIAPOENSIS (MONOGAMY). IN THIS STUDY, I EVALUATE THE MORPHOLOGICAL VARIATION IN THE GEOMETRIC SHAPE OF THE ORBIT BETWEEN SEXES IN THE TWO SPECIES, COMPARING THEIR SOCIAL CONDITION (POLYGYNY, MONOGAMY) AND APPLYING A GEOMETRIC MORPHOMETRICAL METHODOLOGY. THE RESULTS SHOW MORPHOLOGICAL DIFFERENTIATION IN ORBIT SHAPE, SUGGESTING POTENTIALLY ADAPTATIVE CHARACTERS ASSOCIATED WITH SOCIAL CONDITION. THERE ARE VARIETY OF POSSIBLE CAUSES WHICH COULD EXPLAIN THESE DIFFERENCES (E.G., MULTIPLE ORIGINS OF THE SOCIAL SYSTEM IN LIOLAEMUS), WHICH COULD PROVIDE NEW PERSPECTIVES; HOWEVER, THE GENERALIZED LACK OF KNOWLEDGE OF SOCIAL SYSTEMS IN LIOLAEMUS SPECIES IMPOSES BARRIERS TO NEW STUDIES ON THE SUBJECT.

MOST OCEANIC ISLANDS IN THE WORLD HAVE BEEN INVADED BY RATS, WHICH HAVE NEGATIVE EFECTS ON THE LOCAL BIOTA. A NUMBER OF STUDIES HAVE REPORTED RAT PREDATION ON AMPHIBIANS, BUT THERE IS SCARCE INFORMATION ON THE RELATIONS OF TROPHIC INTERACTIONS PRESENT IN THESE CASES (COMPETITION, ORIGIN OF ENERGY PRODUCTION SOURCES, TROPHIC LEVELS). USING DIET DATA AND STABLE ISOTOPES, WE EXPLORED THE TROPHIC INTERACTIONS OF THE ISLA MOCHA IN SOUTHERN CHILE, IN PARTICULAR BETWEEN RATTUS RATTUS (BLACK RAT, INVASIVE) AND EUPSOPHUS INSULARIS (MOCHA ISLAND GROUND FROG, ENDEMIC). THE RESULTS SHOW AN IMPORTANT OVERLAP IN THE PREY USED BY BOTH SPECIES, IN THE TROPHIC POSITIONS THEY OCCUPY, IN THEIR ISOTOPE NICHES AND THE PRESENCE OF ISOTOPIC SIGNALS ATTRIBUTABLE TO THE ANURANS IN TISSUE SAMPLES OF RATS. UNDERSTANDING THE TROPHIC RELATIONS BETWEEN INVADERS AND NATIVE SPECIES IS AN IMPORTANT CHALLENGE FOR THE IMPLEMENTATION OF CONSERVATION PLANS.

THE CHILOTAN ARCHIPELAGO AND SURROUNDING AREAS OF NORTH-WESTERN PATAGONIA (41°?43°S, 72°?74°W) OFFER A UNIQUE OPPORTUNITY TO STUDY THE INTERPLAY BETWEEN THE RECENT GENETIC AND PALEOENVIRONMENTAL EVOLUTION ON TEMPERATE RAINFOREST ENVIRONMENTS. PREVIOUS STUDIES IN THIS REGION HAVE POSTULATED THAT LAND BIOTA PERSISTED WEST OF THE PATAGONIAN ICE SHEET, IN ICE-FREE LOW-ELEVATION REGIONS OF THE MAINLAND, AND THE NORTH-WESTERN PORTION OF ISLA GRANDE DE CHILOÉ DURING QUATERNARY ICE AGES. IN THIS STUDY, WE ANALYSED THE PHYLOGEOGRAPHICAL STRUCTURE (CYTOCHROME B) OF THE IGUANID LIZARD LIOLAEMUS PICTUS TO ESTIMATE THEIR GENETIC STRUCTURE IN RESPONSE TO GLACIAL?INTERGLACIAL CYCLES AND COLONIZATION ROUTES. WE FOUND THAT POPULATIONS FROM THE MAINLAND AND ISLA GRANDE DE CHILOÉ DO NOT SHARE HAPLOTYPES AND, THUS, ARE DIVERGENT HAPLOGROUPS. THIS DIVERGENCE MIGHT REFLECT AN ANCIENT ISOLATION, MUCH OLDER THAN THE LAST GLACIATION. MOREOVER, THE EXISTENCE OF FOUR DIVERGENT HAPLOGROUPS AMONG L. PICTUS POPULATIONS IN THE MAINLAND SUGGESTS THE PERSISTENCE OF MULTIPLE ISOLATED POPULATIONS DURING THE LAST GLACIATION. OUR RESULTS ALSO INDICATE THAT THE COLONIZATION OF SMALL ISLANDS OCCURRED FROM SEVERAL SOURCE SITES, LOCATED BOTH IN THE MAINLAND AND IN ISLA GRANDE DE CHILOÉ, AFTER THE LAST GLACIAL MAXIMUM.

EVAPORITIC ECOSYSTEMS OF THE ATACAMA DESERT CONTAIN A RICH ENDEMIC FAUNA, INCLUDING MOLLUSK SPECIES. A RECENT STUDY PERFORMED IN THE FRESHWATER SNAIL HELEOBIA ATACAMENSIS, ENDEMIC TO THE ATACAMA SALTPAN, REVEALED A STRONG INTERDEPENDENCE OF GENETIC PATTERNS WITH CLIMATIC FLUCTUATIONS AND LANDSCAPE PHYSIOGRAPHY. THE SPECIES IS CURRENTLY LISTED AS CRITICALLY ENDANGERED AT REGIONAL SCALE AND AS DATA DEFICIENT ON THE INTERNATIONAL UNION FOR CONSERVATION OF NATURE (IUCN) RED LIST. HERE, WE STUDIED GENETIC DIVERSITY AND DEMOGRAPHIC HISTORY OF SEVERAL POPULATIONS OF THE SPECIES OCCURRING ON A CONNECTIVITY GRADIENT, INCLUDING SNAILS FROM NEW PERIPHERICAL LOCALITIES (PEINE AND TILOMONTE), WHICH WERE COMPARED WITH TOPOTYPE SPECIMENS. IN ADDITION, WE REASSESSED THE CONSERVATION STATUS USING THE IUCN RED LIST CATEGORIES AND CRITERIA CONSIDERING SPECIES-SPECIFIC IDIOSYNCRASY. PHYLOGENETIC AND PHYLOGEOGRAPHICAL ANALYSES INDICATED THAT SNAILS FROM PEINE AND TILOMONTE BELONG TO H. ATACAMENSIS. WE DISCOVERED SIGNIFICANT DIFFERENTIATION IN SHELL MORPHOLOGY, WHICH WAS GENERALLY GREATER IN GEOGRAPHICALLY ISOLATED POPULATIONS. WE ALSO INFERRED SIX GENETIC CLUSTERS AND A DEMOGRAPHIC EXPANSION CONGRUENT WITH THE WET PERIODS THAT OCCURRED AT THE END OF THE PLEISTOCENE. CONSIDERING THE HIGHEST RISK CATEGORY OBTAINED, H. ATACAMENSIS WAS REASSESSED AS ENDANGERED AT REGIONAL SCALE. FUTURE CONSERVATION PLANS SHOULD CONSIDER THE GENETIC ASSEMBLAGES AS CONSERVATION UNITS.

NANNOPHRYNE VARIEGATA IS AN ENDEMIC SPECIES OF THE SOUTHERN FORESTS OF CHILE AND ARGENTINA. IT HAS A WIDE DISTRIBUTION IN CHILEAN TERRITORY AND TO A LESSER EXTENT, IN ARGENTINE TERRITORY. ALONG THIS EXTENSIVE LATITUDINAL DISTRIBUTION, IT INHABITS DIFFERENT ECOLOGICAL REGIONS, CHARACTERIZED MAINLY BY LOW TEMPERATURES AND HIGH PRECIPITATION. THERE ARE FEW ANTECEDENTS REGARDING HABITAT PREFERENCES AND THREATS TO THIS SPECIES. THIS PAPER REPORTS ON NEW DISTRIBUTION RECORDS IN THE EXTREME SOUTH OF CHILE AND ARGENTINA. IT ALSO DESCRIBES THE CHARACTERISTICS OF THE HABITATS IT OCCUPIES AND THE REPRESENTATION IN PROTECTED AREAS OF BOTH COUNTRIES. NANNOPHRYNE VARIEGATA IS DISTRIBUTED FROM 37º28? TO 52°10? SOUTH LATITUDE, BECOMING ONE THE SOUTHERNMOST AMPHIBIANS IN THE WORLD. IT INHABITS DIFFERENT ENVIRONMENTS THAT INCLUDE HUMID FOREST ASSOCIATIONS, PEAT BOGS, MAGELLANIC TUNDRA AND NEIGHBORING HIGH ANDEAN ENVIRONMENTS. IT IS WELL REPRESENTED IN PROTECTED AREAS WITH A LARGE NUMBER OF OBSERVED POPULATIONS.

BACKGROUND: CLINAL VARIATION IS DEFINED AS GRADUAL VARIATION IN A CHARACTER ASSOCIATED WITH GEOGRAPHIC DISTANCE AMONG SITES. MICROLOPHUS ATACAMENSIS IS A MEDIUM LARGE LIZARD SPECIES WHICH INHABITS THE INTERTIDAL ZONE OF NORTHERN CHILE, DISTRIBUTED FROM ANTOFAGASTA (23° 39? S) TO ARRAYÁN, LA SERENA (29° 41? S) IN A GRADIENT WHICH COULD SHOW CLINAL VARIATION. GEOMETRIC MORPHOMETRICS ANALYZES DIFFERENCES IN SHAPE INDEPENDENT OF SIZE; INFORMATION ABOUT SHAPE ALLOWS A MORE COMPLETE BIOLOGICAL INTERPRETATION THAN INFORMATION ON MORPHOLOGICAL VARIATION. THIS STUDYEVALUATED CLINAL VARIATION IN THE HEAD SHAPE OF M.ATACAMENSIS FROMFIVE LOCALITIES (ANTOFAGASTA, PAPOSO, PAN DE AZÚCAR, CALDERA, AND TRES PLAYITAS) USING DORSAL AND LATERAL VIEWS, COMPARING FORM VARIATION WITH LATITUDINAL DISTRIBUTION. THE HEADS OF ADULTS COLLECTED WERE PHOTOGRAPHED IN LATERAL AND DORSAL VIEWS. RESULTS: THE ANALYSIS DID NOT FIND SIGNIFICANT DIFFERENCES IN FORM AMONG THE FIVE LOCALITIES, IN CONTRAST TO THE PROPOSAL OF EARLIER STUDIES, AND NO DIFFERENCES WERE RECORDED BETWEEN THE SEXES. POSSIBLE REASONS WHY THESE POPULATIONS ARE NOT DIFFERENTIATED IN THE LATITUDINAL GRADIENT ARE DISCUSSED. CONCLUSIONS: OUR RESULTS SHOW THAT THERE ARE NO DIFFERENCES BETWEEN THE STUDIED, AMONG THE EXPLANATIONS ARE THAT POPULATIONSOF THIS SPECIES ARE SUBJECTED TO SIMILAR ENVIRONMENTS THAT PROMOTE CONVERGENCE OF THE STRUCTURES ANALYZED.

IN THIS STUDY, WE FOCUS ON THE EVALUATION OF THE CONSERVATION PRIORITY OF AMPHIBIAN SPECIES IN CHILE. WE EMPHASIZE THE IMPORTANCE OF ESTABLISHING STANDARDIZED CRITERIA TO EVALUATE AND CLASSIFY THIS PRIORITY, CONSIDERING FACTORS SUCH AS EXTINCTION RISK, GEOGRAPHIC DISTRIBUTION, AND ECOLOGICAL IMPORTANCE. WE ESTABLISH PRIORITY CATEGORIES FOR SPECIES, ALLOWING US TO IDENTIFY THOSE THAT REQUIRE IMMEDIATE ATTENTION IN TERMS OF CONSERVATION. SIX SPECIES WITH A HIGH PRIORITY, EIGHT WITH A MEDIUM PRIORITY, TWENTY-TWO WITH A LOW PRIORITY, AND TWENTY-TWO WITH NO PRIORITY WERE IDENTIFIED. WE EMPHASIZE THE RELEVANCE OF THE TELMATOBIIDAE AND ALSODIDAE FAMILIES AS CONSERVATION PRIORITIES, HIGHLIGHTING THE NEED TO FOCUS OUR CONSERVATION EFFORTS ON THESE AMPHIBIAN FAMILIES IN CHILE. THIS APPROACH PROVIDES A SOLID BASIS FOR INFORMED DECISION MAKING IN THE ALLOCATION OF LIMITED RESOURCES FOR BIODIVERSITY CONSERVATION.