Windsor E. Aguirre

DePaul University · Biological Sciences

Rocio is a small genus of Neotropical freshwater fishes that is distributed in Atlantic drainages of northern Middle America. Two species of Rocio , R. spinosissima and R . octofasciata, exhibit sympatry in the Río Dulce basin in eastern Guatemala. Rocio spinosissima is endemic to the Río Dulce basin, while R . octofasciata has a larger geographic...

The Neotropical region hosts 4225 freshwater fish species, ranking first among the world's most diverse regions for freshwater fishes. Our NEOTROPICAL FRESHWATER FISHES data set is the first to produce a large‐scale Neotropical freshwater fish inventory, covering the entire Neotropical region from Mexico and the Caribbean in the north to the southe...

The reproductive behaviour of the Andean catfish Astroblepus ubidiai was observed directly and with an underwater camera in a spring located next to Lago San Pablo in the province of Imbabura, Ecuador, in late 2015 and early 2016. Five mating attempts were observed, four of which were video‐taped, and two of which resulted in complete copulation. D...

The Threespine Stickleback is ancestrally a marine fish, but many marine populations breed in fresh water (i.e., are anadromous), facilitating their colonization of isolated freshwater habitats a few years after they form. Repeated adaptation to fresh water during at least 10 million years and continuing today has led to Threespine Stickleback beco...

Urbanization transforms environments in ways that alter biological evolution. We examined whether urban environmental change drives parallel evolution by sampling 110,019 white clover plants from 6169 populations in 160 cities globally. Plants were assayed for a Mendelian antiherbivore defense that also affects tolerance to abiotic stressors. Urban...

Urbanization transforms environments in ways that alter biological evolution. We examined whether urban environmental change drives parallel evolution by sampling 110,019 white clover plants from 6169 populations in 160 cities globally. Plants were assayed for a Mendelian antiherbivore defense that also affects tolerance to abiotic stressors. Urban...

Freshwater fish communities in Ecuador exhibit some of the highest levels of diversity and endemism in the Neotropics. Unfortunately, aquatic ecosystems in the country are under serious threat and conditions are deteriorating. In 2018–19, the government of Ecuador sponsored a series of workshops to examine the conservation status of Ecuador's fresh...

Similar forms often evolve repeatedly in nature, raising long-standing questions about the underlying mechanisms. Here, we use repeated evolution in stickleback to identify a large set of genomic loci that change recurrently during colonization of freshwater habitats by marine fish. The same loci used repeatedly in extant populations also show rapi...

Introducción: Las diferencias morfológicas son el producto de la plasticidad fenotípica, la adaptación genética o la deriva genética, pero no siempre se requiere de poblaciones muy antiguas para conseguir adaptaciones locales si se presentan factores selectivos. Objetivo: Este trabajo examina la variación en la forma del cuerpo de peces en ríos co...

Similar forms often evolve repeatedly in nature, raising longstanding questions about the underlying mechanisms. Here we use repeated evolution in sticklebacks to identify a large set of genomic loci that change recurrently during colonization of new freshwater habitats by marine fish. The same loci used repeatedly in extant populations also show r...

The bottlenose dolphin is one of the most common cetaceans found in the coastal waters, estuaries, and mangroves of Ecuador. However, its population size is gradually declining in the Gulf of Guayaquil, and anthropogenic factors including habitat degradation, uncontrolled dolphin watching, dredging activities, increasing maritime traffic, underwate...

Environmental changes can modify the phenotypic characteristics of populations, which in turn can influence their evolutionary trajectories. In ectotherms like fishes, temperature is a particularly important environmental variable that is known to have significant impacts on the phenotype. Here, we raised specimens of the surface ecomorph of Astyan...

Ecuador's official Red list for freshwater fish La construcción de las Listas Rojas, fue una iniciativa del Ministerio del Ambiente a través de la Dirección Nacional de Biodiversidad y en el marco del Proyecto Paisajes – Vida Silvestre; oficializadas mediante Acuerdo Ministerio 069 del 23 de julio de 2019. Las mismas fueron elaboradas por especial...

Vertebral number is adaptively important in fishes and is associated with body shape at broad taxonomic ranks. Less is known about this association within species. Rhoadsia is a deep-bodied characid genus endemic to western Ecuador and northwestern Peru. It includes two species differing in body depth (BD), described from different drainages and el...

Neotropical mountain streams are important contributors of biological diversity. Two species of the characid genus Rhoadsia differing for an ecologically important morphological trait, body depth, have been described from mountain streams of the western slopes of the Andes in Ecuador. Rhoadsia altipinna is a deeper-bodied species reported from low...

Water temperature at sampling sites measured during specimen collection. Temperature data for the Esmeraldas and Jubones sites were measured in July 2014 and for the Santa Rosa River in July 2013. (TIF)

Haplotype frequency of COI mtDNA gene for Rhoadsia samples. N is the number of specimens per sample. (DOC)

S7 intron allele frequencies for Rhoadsia samples. (DOC)

Catalog numbers for voucher specimens deposited in museums listed by drainage and site specimen number listed in parenthesis for sites with more than one lot examined. CAS: California Academy of Sciences, FMNH: Field Museum of Natural History, MECN: Museo Ecuatoriano de Ciencias Naturales (Ecuador), MUGT: Museo de Ciencias Naturales de la Universid...

Landmarks and linear measures used in the study. Insect pins were used to mark some of the landmarks that were difficult to see from a lateral perspective. SL is standard length and BD is body depth. The specimen in the photo is a male from the Santa Rosa River collected at the 31 m site. Scale bar is 10mm. (TIF)

Standard length variation among samples. E = Esmeraldas River, J = Jubones River, SR = Santa Rosa River, and GO = Guayas and other small neighboring drainages. (TIF)

Water quality data for the sampling sites in the Esmeraldas, Jubones, and Santa Rosa river drainages. (DOC)

Elevational gradients for the sampling sites in the Esmeraldas, Jubones and Santa Rosa rivers. Distances from ocean are approximate and were measured along river courses in Google Maps. (TIF)

Pairwise FST values between samples. COI gene below diagonal, S7i2 gene above diagonal. Significant FST values in bold with asterisks indicating the level of significance. (DOC)

We report collections of several specimens of Sicydium in 2013 and 2014 from the Jubones and Santa Rosa Rivers in southwestern Ecuador. These collections substantially expand the known range of the genus southward. The specimens are tentatively identified as Sicydium cf. rosenbergii based on their morphology. Small differences in morphology among s...

Background: Marine or anadromous threespine stickleback have colonized many northern Holarctic lakes after glacial recession, and their freshwater descendants have diverged in characteristic ways. Such divergence begins within a few generations, but previous studies have sampled only one generation or initiated sampling several generations after th...

The genus Rhoadsia is endemic to western Ecuador and northern Peru and includes two described species that differ in body form, size, and the elevations at which they occur. Unfortunately, there is uncertainty about the number of species that should be recognized in the genus and the causes of the morphological variation documented within and betwe...

Background: Many fishes have evolved long bodies. Decades of research have uncovered substantial variability in body form within the threespine stickleback, Gasterosteus aculeatus, and among its relatives in the Gasterosteoidei, including the evolution of extremely long bodies. Elongation is likely to be associated with the evolution of the axial s...

Understanding how the vertebral column is impacted as populations adapt to different habitats favouring distinct body forms can provide insight into the origin of evolutionary diversity in the axial skeleton. We examined variation of vertebral number and body shape in morphologically and ecologically divergent anadromous, benthic, and limnetic thre...

Abstract: Iotabrycon praecox (Characidae: Stevardiinae) has been reported as endemic to the Guayas River drainage in Western Ecuador since its description in 1973. We collected one specimen of I. praecox in the Santa Rosa River, Santa Rosa drainage, El Oro Province, approximately 144 km south of the Guayas drainage, significantly expanding the know...

Sixteen polymorphic, dinucleotide microsatellite loci were developed for Rhoadsia altipinna, a small characid fish from impacted rivers in south western Ecuador. None of the loci were in linkage disequilibrium or deviated significantly from Hardy–Weinberg equilibrium after sequential Bonferroni correction. Variability was relatively high with allel...

Little is known about the freshwater fishes of western Ecuador despite serious environmental threats including the creation of large artificial impoundments. Phenotypic and genetic divergence of populations of a large predatory fish, Hoplias microlepis, is examined in rivers and artificial impoundments of the Guayas River drainage in western Ecuado...

The genetic relationship between sympatric, morphologically divergent populations of anadromous and lake-resident three-spined stickleback Gasterosteus aculeatus in the Jim Creek drainage of Cook Inlet, Alaska, was examined using microsatellite loci and mitochondrial d-loop sequence data. Resident samples differed substantially from sympatric anadr...

Background: Adaptive radiation in the threespine stickleback (Gasterosteus aculeatus) is dramatic, highly replicated, and predictable. Goals: Test hypotheses that divergent phenotypes of freshwater threespine stickleback evolve at the same rate as in other species and that derived freshwater and ancestral oceanic (i.e. marine or anadromous) phenoty...

We developed 14 polymorphic, dinucleotide microsatellite loci for Hoplias microlepis, a large predatory fish from a highly impacted river in western Ecuador. These were isolated using a next-generation pyrosequencing approach and tested in a sample of 32 fish. None of the loci were in linkage disequilibrium and all appeared to be in Hardy–Weinberg....

Analysis of contemporary evolution can provide important insights into the pattern and rate of phenotypic evolution. The threespine stickleback population in Loberg Lake was exterminated in 1982, and a new population was founded between 1983 and 1989 by anadromous stickleback. The body shape of the Loberg Lake population resembled that of anadromou...

Plerocercoids of the cestode Schistocephalus solidus are reported for the first time from the body cavity of anadromous threespine stickleback inhabiting Mud Lake, Alaska. Most infected stickleback harbored a single large plerocerciod (mean weight  =  0.447 g, range  =  0.228-0.716 g). The overall prevalence of plerocercoids across genders and 2 yr...

The threespine stickleback (Gasterosteus aculeatus) is primitively an anadromous or resident marine species but has repeatedly colonized fresh water, where predictable phenotypic divergence usually occurs rapidly. A conspicuous element of this divergence is change of the number and position of lateral armor plates from about 33 that cover the entir...

This study examined sexual dimorphism of head morphology in the ecologically diverse three-spined stickleback Gasterosteus aculeatus. Male G. aculeatus had longer heads than female G. aculeatus in all 10 anadromous, stream and lake populations examined, and head length growth rates were significantly higher in males in half of the populations sampl...

Adaptive radiations are a major source of evolutionary diversity in nature, and understanding how they originate and how organisms diversify during the early stages of adaptive radiation is a major problem in evolutionary biology. The relationship between habitat type and body shape variation was investigated in a postglacial radiation of threespin...

We investigated the evolution of a large facial bone, the opercle (OP), in lake populations of the threespine stickleback that were founded by anadromous ancestors, in Cook Inlet, Alaska. Recent studies characterized OP variation among marine and lake populations and mapped a quantitative trait locus with a large influence on OP shape. Using popula...

We infer the phylogeny of fishes in the New World Cynoscion group (Cynoscion, Isopisthus, Macrodon, Atractoscion, Plagioscion) using 1603bp of DNA sequence data from three mitochondrial genes. With the exception of Plagioscion, whose position was ambiguous, the Cynoscion group is monophyletic. However, several genera examined are not monophyletic....

Ancestral properties can influence patterns of evolutionary diversification, but ancestors can rarely be observed directly. We examined variation and sexual dimorphism of morphological traits in an anadromous threespine stickleback population representing the ancestral form for resident postglacial stickleback populations in the area. A combination...

Overall, the volume starts in a very logical fashion but then descends in a more fractured body of work where the connection among articles is difficult to ascertain. Thus, the papers become self-contained with a lack of continuity not unusual for a collection of short review articles/brief reports. However, most of them are interesting and well wr...

How does development evolve to produce a skeletal element with a new shape? We extend our previous study of morphological evolution and development of the opercle, a large facial bone with favorable attributes for both comparative and development analyses. The opercle becomes prominently reshaped when Alaskan anadromous stickleback fish evolve into...

A 7.25 m long male humpback whale (Megaptera novaeangliae) with spondylitis was found beached on August 13, 1994 at Ancon, Ecuador (2 degrees 23' S, 80 degrees 47' W). The condition involved at least 11 vertebrae, 7 lumbar (L4 to L11) and 4 caudal (Ca1 to Ca4). Partial fusion of vertebrae was observed as a result of intervertebral bony proliferatio...

Coastal Ecuador has lost 20–30% of mangrove wetlands over the past 30 years. Such habitat loss can impair the ecological functions of wetlands. A paucity of information exists concerning mangrove fish communities of Ecuador. In this study we identify the fish community of the remaining mangrove wetland in Palmar, Ecuador. Fish were sampled in the d...

Se recolectaron trece ejemplares juveniles de Sphoeroides rosenblatti Bussing, 1996 en un bosque pequeño y fuertemente impactado de mangle situado en Palmar, provincia de Guayas, Ecuador. Esta especie era conocida previamente solo de aguas costeras de Costa Rica y Panamá. Se contrastó la ocurrencia y morfología de S. rosenblatti con ejemplares de S...

In summary, we report the occurrence of a new species of pufferfish, S. rosenblatti, for the continental coast of Ecuador, which appears closely related to, and occurs, sympatrically with, the common pufferfish species S. annulatus in mangrove forests. The two species differ morphologically (although the differences are subtle among juvenile fish),...

We assess morphological diversity of species of the Cynoscion group in the Gulf of Guayaquil (GOG) using traditional morphometric methods. Five species from the GOG assemblage (C. albus, C. analis, C. phoxocephalus, C. squamipinnis, and Isopisthus remifer) are compared to four species from a relatively well-studied assemblage in the western Atlanti...

We describe an unidentified species of the genus Neoechinorhynchus occurring in the intestine of the marine fish Micropogonias altipinnis using scanning electron microscopy (SEM). The genus Neoechinorhynchus occurs mostly in freshwater fishes; this may be the first report of its occurrence in the marine fish genus Micropogonias and the New World Sc...

Twenty-seven crosses were used to study the genetics of rapidly evolving traits in a recently founded population of threespine stickleback in Loberg Lake, Alaska. Lateral plate morph segregation ratios were inconsistent with all published models of lateral plate morph genetics except Avise's (1976) general two-locus model. Incompatibility of the re...

Loberg Lake, Alaska was colonized by sea-run Gasterosteus aculeatus between 1983 and 1988, after the original stickleback population was exterminated. Annual samples from 1990 to 2001 reveal substantial evolution of lateral plate (armor) phenotypes. The 1990 sample was nearly monomorphic for the complete plate morph, which is monomorphic in local s...

Loberg Lake, Alaska was colonized by sea-run Gasterosteus aculeatus between 1983 and 1988, after the original stickleback population was exterminated. Annual samples from 1990 to 2001 reveal substantial evolution of lateral plate (armor) phenotypes. The 1990 sample was nearly monomorphic for the complete plate morph, which is monomorphic in local s...

The sulcus of Cynoscion spp. exhibited strong positive allometric growth relative to the medial surface of the otolith, and the ratio between the area of the sulcus and the otolith (S:O) increased dramatically with size. The S:O ratios of larger specimens are the highest that have so far been reported.

We were used polymerase chain reaction (PCR) and direct sequencing of 405 nucleotides of the mitochondrial cytochrome b gene to elucidate the interrelationships among several species of the genera Bairdiella (croakers) and Macrodon (weakfishes) from the eastern Pacific and western Atlantic. The nucleotide sequence analysis clearly distinguished eac...