Acta Zoológica Lilloana

Dr. Luis Emilio Grosso (1942-2025)

2025-11-20T10:26:16-03:00

Luis Emilio Grosso, nació en S.S. de Jujuy, Argentina en el año 1942. Cursó sus estudios en la ciudad de La Plata. Obtuvo los títulos de Licenciado en Zoología otorgado por la Facultad de Ciencias Naturales y Museo de la Universidad Nacional de La Plata y Doctor en Ciencias Naturales otorgado por la misma unidad académica. Su tesis doctoral, bajo la dirección de la Dra. Julia A.Vidal Sarmiento, se titula “Contribución al conocimiento biológico y sistemático de las especies argentinas de Noteridae (Coleoptera Adephaga)”.

Histomorphology and histochemistry of the digestive tract in female Leptodactylus latinasus (Anura: Leptodactylidae) during the reproductive period

2025-09-01T10:31:55-03:00

The digestive tract is responsible for the digestion and absorption of
nutrients required for energy supply. The functional state of the organs
that compose it reflects a clear association between the animal’s habi-
tat and its physiology. The aim of this study is to perform a histological
analysis of the cellular and tissue structures of the esophagus, stomach,
small intestine, and large intestine, in order to contribute to a compre-
hensive understanding of the system and its influence on the repro-
ductive biology of the species. Fifteen female specimens of Leptodac-
tylus latinasus were dissected; the organs were removed, cleaned, and
processed using standard histological techniques. Tissue sections were
stained with Hematoxylin and Eosin, Mallory’s Trichrome, Alcian Blue
at pH 0.5 and 2.5, and Periodic Acid-Schiff (PAS). The histomorpholog-
ical analysis revealed features shared with other species; however, the
presence of gastric glands composed of (1) mucous neck cells, (2) chief
cells, and (3) parietal cells appear to be a trait not commonly observed
in most species. Furthermore, the histochemical analysis identified six
types of glands differentiated by the chemical nature of their contents.
This study demonstrates that female Leptodactylus latinasus specimens
exhibit histological characteristics along the digestive tract that enable
efficient digestion and nutrient assimilation. The high glandular activity
revealed by the histochemical analysis reflects an active feeding phase
during the reproductive period, ensuring energy reserves that support
successful egg-laying.

Fire-Induced Changes in Daily Butterfly Assemblages in Mediterranean Forests: Insights from the Edough Massif, Algeria

2025-09-01T10:31:45-03:00

Forest fires significantly alter the biodiversity of Mediterranean ecosystems, particularly butterfly communities, which are sensitive bioindicators of environmental changes. This study compares the diversity and structure of diurnal butterflies in two cork oak forests of the Edough Massif (Algeria): a natural forest and a post-fire forest, based on surveys conducted from March to July 2023.

Butterfly sampling was carried out using two complementary methods: a modified linear transect approach based on the British Butterfly Monitoring Scheme (BMS) and the Kilometric Abundance Index (KAI). Species abundances were recorded along predefined transects under standardized conditions.

The results show a significant decline in species diversity after the fire, with only 11 species recorded in the burned habitat compared to 31 in the natural forest. Abundance analysis reveals that some sensitive species disappear or become rare, while others, more fire-resistant, benefit from the newly created ecological conditions. The Bray-Curtis index highlights a moderate but notable transformation of butterfly communities.

These findings confirm that fire acts as an ecological filter, structuring populations according to their tolerance to disturbances. The study emphasizes the need for adapted management and restoration strategies to mitigate the effects of wildfires and promote the resilience of Mediterranean ecosystems.

Rensch’s postulate is not accomplished among tits (Paridae: Passeriformes)

2025-09-01T10:31:52-03:00

Rensch's allometric postulate states that the degree of sexual size dimorphism increases with body size in species where the male is the largest sex and, conversely, decreases in those species where the female is the largest sex. From 30,222 biometric records (wing length and length of the 3rd primary feather) of 5 species of tits (Periparus ater, Cyanistes caeruleus, Lophophanes cristatus, Parus major and Poecile palustris), it was analysed whether that postulate is applicable. For both lineal measures, regressions between sexes appeared isometrical, thus indicating that among these Parid birds, Rensch’s postulate does not apply. It can be argued that this accomplishment is due to the polygyny of these species, plus the fact that both sexes contribute equal to the feeding of the siblings. Moreover, consequently, the consumption of food resources is proportionally the same between sexes, since if the weight ratio between males and females is maintained, it is reasonable to suppose that metabolic rates follow similar proportion.

Occurrence and morphological variability of Hydra (Hydroida: Hydridae) in freshwater bodies of Southeast of Buenos Aires Province, Argentina

2025-09-01T10:31:47-03:00

Hydra constitutes a monophyletic clade of sessile and solitary polyps
that occur on all continents except Antarctica. Despite its widespread
presence in freshwater habitats, Hydra requires reasonably unpollut-
ed conditions for survival, making its presence a reliable indicator of
good water quality and a certain degree of ecosystem conservation.
Since their discovery, these polyps have become valuable biological
models due to their morphological simplicity, global distribution, and
low maintenance requirements in the laboratory conditions, enabling
experiments on regeneration, reproduction, senescence, cellular differ-
entiation, among other processes. All Hydra species are clustered into
four morphological groups: viridissima (green), vulgaris (common), oli-
gactis (stalked), and braueri (gracile). Species in the viridissima group
are green due to the presence of intracellular symbiotic algae, whereas
the brown hydras (braueri, oligactis, and vulgaris) lack such endosym-
bionts. The oligactis and braueri groups are restricted to the Northern Hemisphere, while the viridissima and vulgaris groups include cosmo-
politan species. To date, only five published records documenting the
presence of Hydra in Argentina are available in the scientific literature.
In the present study, we report six new occurrences from four wetlands
in the southeastern region of Buenos Aires Province: two each for H.
viridissima, H. vulgaris, and H. vulgaris pedunculata. The study includes
a quantitative morphological analysis (body measurements, cnidome,
and reproductive structures) to assess intraspecific variation among pop-
ulations from different freshwater bodies. These findings expand the
known distribution of Hydra in South America and provide reference
data for future ecological and taxonomic studies.

Breeding ecology of the Loja Hummingbird Amazilis amazilia alticola (Apodiformes: Trochilidae) in Loja, Ecuador

2025-09-01T10:31:43-03:00

We present for the first time detailed information regarding the reproductive biology of the Loja Hummingbird (Amazilis amazilia alticola) in the wild. This research was carried out between February and March 2022 in the city of Loja, Ecuador, through detailed observations of an active nest located in a loquat tree (Eriobotrya japonica). We recorded data concerning the nest, its structure, construction materials and size. We also review all available information regarding this species’ breeding phenology. The nest was built using plant fibers, spider webs and lichens for insulation and camouflage. The incubation lasted 16 to
18 days, and the chicks remained in the nest for 23 days. Typical for hummingbirds, the female assumed all parental duties, including the incubation, care and feeding of the young, collecting nectar from at least eight plant species. Significant differences were observed in the care given to each chick. Our data improves our knowledge regarding
the reproduction of Andean hummingbirds, and in articular of these common but poorly known species that have adapted to anthropic environments.

Silent Invaders : Biodiversity at Risk, Social Media findings into Exotic Pet Trade in Tamil Nadu and Invasion Modeling of Iguana iguana (Linnaeus, 1758)

2025-10-24T11:27:06-03:00

This study investigates the exotic pet trade in Tamil Nadu by analyzing YouTube videos, which revealed the presence of 148 pet species being sold in pet shops. Among these, 12 species were classified as Endangered, 15 as Vulnerable, 3 as Near Threatened, 101 as Least Concern, and 18 as Not Assessed, according to the IUCN Red List. The CITES status of each species was also examined to assess their trade regulations. Additionally, the presence of invasive alien species recorded in the videos and already existing in the wild in India was mapped. Species distribution modelling using MaxEnt was conducted for Iguana iguana globally, evaluating both current and future habitat suitability. Results indicated a high potential for the species to establish itself and reproduce in India, posing a serious ecological threat. A questionnaire survey among pet shop owners disclosed limited awareness of pet trade regulations and breeding practices. Overall, the findings highlight the urgent need for stricter enforcement of pet trade laws, increased public awareness, and proactive measures to prevent potential invasions by exotic species.

Historical reports of güiña, Leopardus guigna tigrillo (Carnivora: Felidae), in San Antonio province and new records in El Quisco commune, Valparaíso region, Chile

2025-10-24T11:27:01-03:00

Leopardus guigna, commonly known as güiña or kodkod, is a felid endemic to the temperate forests of southern South America, currently classified as Vulnerable by the IUCN. Its presence in central Chile has been scarcely documented, particularly in San Antonio Province (Valparaíso region), where urban development has led to severe habitat loss. This article presents historical records of the species and new detections obtained between 2021 and 2025 through camera trap surveys conducted in coastal ravines within the communes of El Quisco and San Antonio. Monitoring campaigns were conducted with and without scent lures, recording species presence, behavior, co-occurrence with native fauna, and threats such as free-ranging domestic dogs and cats.

Recent detections were recorded in Quebrada de Córdova, Los Colihues, and Carvajal (El Quisco), as well as Fundo Llolleo (San Antonio), alongside 28 historical records within the province. Ravines with vegetation cover, water flow, and ecological connectivity emerged as key habitats and potential ecological corridors for the species. In areas with lower anthropogenic pressure, such as Fundo Llolleo, no domestic dogs were detected, contrasting with more urbanized ravines. The co-occurrence of güiña with other native species suggests complex trophic interactions. These findings expand current knowledge of the güiña’s distribution in central Chile and emphasize the need to incorporate its conservation into territorial planning. Furthermore, the results underscore the importance of sustained monitoring to assess population viability in fragmented landscapes.

Efficiency of Porcellio laevis (Isopoda: Porcellionidae) as a cadmium remover in agricultural soils, at laboratory level

2025-10-24T11:27:03-03:00

The present study aimed to evaluate the efficiency of the terrestrial isopod Porcellio laevis in removing cadmium (Cd) from contaminated agricultural soils at laboratory level. The study employed an experimental design with five doses and four replications, using cadmium chloride (CdCl₂) as a contaminant. 10 kg of clay loam soil were prepared and a control and four doses of Cd were established: 20 mg.Kg^-1 (T₁), 80 mg.Kg^-1 (T₂), 240 mg.Kg^-1 (T₃) and 400 mg.Kg^-1 (T₄). 40 individuals of P. laevis were introduced per dose and incubated for 60 days. The physicochemical characteristics of the soil and the doses of Cd in the soils and in the isopods at the beginning and at the end of the study were analyzed, evaluating the removal of Cd (%R) and the bioaccumulation factor (BAF). The results revealed removal rates of Cd from the soil that increased with the initial dose of Cd and the exposure time, reaching 86.9% in the treatment with 400 mg.Kg^-1 Cd. However, the mortality rate increased significantly with the dose of Cd, reaching 92,5% in the treatments with 240 and 400 mg.Kg^-1 Cd at the end of the study. This exposure to Cd caused significant morphological changes in the isopods, including size reduction, alterations in pigmentation and deformities in the shell. These findings suggest that P. laevis is an effective bioaccumulator for the remediation of agricultural soils contaminated with Cd.

Solving a taxonomic enigma in the Nevados del Aconquija, Catamarca, Argentina: a new endemic species of Liolaemus (Iguania: Liolaemidae)

2025-11-18T10:50:36-03:00

The Liolaemus montanus group is currently the most diverse clade within the genus, with more than 75 described species. It is distributed from Peru to Mendoza, Argentina, including localities in Bolivia and Chile. Species of this group primarily inhabit high-altitude areas characterized by cold and harsh climates. Recent phylogenetic studies indicate that the L. montanus group includes twelve monophyletic groups. One of these is the L. huacahuasicus clade, which includes ten valid species and several populations considered candidate species. In recent years, several new species of the L. montanus group have been described, mainly from Peru, Argentina and Bolivia. In this study, we describe a new species of the subgenus Eulaemus, belonging to the L. montanus group, L. huacahuasicus clade. This new taxon is highly endemic to the Nevados del Aconquija, Catamarca, Argentina. This mountain range, includes several peaks exceeding 5000 meters above sea level. Its eastern slopes harbor a lush flora, while the western slopes are rocky and desert-like. The Nevados del Aconquija form a massif oriented in a northeast-southwest direction, constituting the natural border between Catamarca and Tucumán. The new Liolaemus inhabits the western slopes, at elevations above 4000 meters, and exhibits a unique combination of traits that support its recognition as a new species to science. Phylogenetic analyses indicate a close relationship between the new species and Liolaemus huacahuasicus, with which it was previously confused. However, the geographic distribution of L. huacahuasicus is restricted to the Calchaquí summits in Tucumán.

First record of Brontocoris tabidus and Podisus spp. (Heteroptera: Pentatomidae) as predators of Actinote sp. (Lepidoptera: Nymphalidae)

2025-11-18T10:50:29-03:00

The genus Actinote is one of the most diverse of Nymphalidae in the Neotropical region, with 35 species. Among them, Actinote pellenea Hübner stands out as widely distributed throughout South America. Although aspects of its biology have been documented, little is known about its natural control agents. The objective was to report for the first time the predation by Podisus nigrispinus, P. graziae, and Brontocoris tabidus on different developmental stages of Actinote sp. under natural environmental conditions. Sampling was conducted through active observation along a 250-meter transect in a locality in Jujuy Province, Argentina. Asopine bugs were collected manually and predation events were documented. One adult of B. tabidus, three adults of P. graziae, and seven specimens of P. nigrispinus (one adult and six nymphs) were recorded. The species B. tabidus was observed preying on an Actinote pupa, while Podisus species consumed larvae, pupae, and adults. Most events corresponded to the pupal stage, suggesting greater vulnerability during this phase. Attack patterns and preference for specific body regions of the prey were also described. This work represents the first record of P. graziae for Argentina and extends the distribution of B. tabidus to Jujuy Province. Furthermore, this is the first report of B. tabidus and Podisus spp. preying on immature stages and adults of Actinote under natural conditions. These findings expand knowledge about the trophic behavior of these species in wild environments.

The American Barn Owl (Tyto furcata) importance in rodent predation with possible zoonotic potential in rural landscape of Campeche, México

2025-11-18T10:50:31-03:00

The systematic increase in the abundance of rodents and their cascading
negative effects on increasingly anthropized landscapes is generating
greater research interest from their predators. In this study, we analyze
the prey species composition in the Tyto furcata diet, to contribute
locating its importance in the control of pest rodent populations with
zoonotic potential at the local and state levels. From 39 pellets collected
in 2024 in the rural community of Nilchí, Campeche, Mexico, a total
of 54 individuals were identified that taxonomically belong to three
orders of mammals, with 96.3% of the prey items being rodents, of
which Sigmodon toltecus and Mus musculus represented 50 and 37 %
respectively. Based on the results and literature review, it was found
that different zoonotic pathogens are reported for both species, so it
can be assumed that in the study location T. furcata is preying on the
rodent species with the greatest abundance and zoonotic potential.
However, the importance of this prey bird as a biological controller has
received very little attention in the Yucatan Peninsula, so it is essential
to conduct studies that consider the ecological and health significance
that this owl plays in the predator-prey-vector-pathogen system, and
therefore, its importance in controlling the transmission of zoonotic
diseases, especially if at the regional level it is usually killed for being
associated with negative mythical aspects.

Potential distribution of Kinosternon cora (Testudines: Kinosternidae) and implications for its conservation

2025-11-18T10:50:32-03:00

Kinosternon cora, an endemic turtle of the Pacific Coastal Plain in
Sinaloa and Nayarit, Mexico, is classified as “Endangered” due to its
restricted distribution, habitat loss, and illegal collection. This study
modeled its potential distribution using MaxEnt and 48 verified pres-
ence records, analyzing bioclimatic variables (mean annual tempera-
ture, diurnal temperature range, temperature of the warmest quarter,
precipitation of the driest and coldest quarters). The LQPTH/?3 model
showed high performance (AUC = 0.970, pROC = 1.51, p = 0.001),
predicting 3,548.27 km² of suitable habitat with 85.9% overlap with the
known distribution. Mean annual temperature (29.5–30.0°C) and low
dry-season precipitation (<100 mm) were the most influential predic-
tors, contributing 41.64% and 22.2% to the model, respectively, with
optimal diurnal temperature ranges (10.0–16.0°C) and warmest quar-
ter temperatures (28.5–30.0°C), reflecting reliance on thermally stable
wetlands. Precipitation in the coldest quarter had no significant effect.
These results identify climatically suitable areas for K. cora, highlighting
the need to protect aquatic and semi-aquatic habitats threatened by
wetland degradation and illegal trade. Unconfirmed predicted areas
suggest zones for targeted surveys to refine distribution knowledge.
This study supports conservation efforts by identifying priority areas for habitat protection and recommending the integration of non-bioclimatic
variables, such as vegetation cover, to refine future distribution models.

A new species (Inezia inornata) and documented records of little-known birds (Buteo brachyurus, Nyctidromus albicollis, Leptodon cayanensis, Falco rufigularis) for the province of Santa Fe, Argentina, in the Humid Chaco ecoregion

2025-11-18T10:50:34-03:00

The province of Santa Fe, in the region known as “Cuña Boscosa,” includes approximately 10,000 km² of forests that are part of the southernmost portion of the Humid Chaco ecoregion. Biologically, this region has been poorly studied, even from an ornithological perspective, despite being categorized as an Important Bird Area (IBA). As a result, new species continue to be recorded, which may further enhance its value as an IBA. This study reports the presence of a new species breeding in the area, the Plain Tyrannulet (Inezia inornata), as well as four species whose presence required confirmation due to a lack of documented evidence (Buteo brachyurus, Nyctidromus albicollis, Falco rufigularis) or because only very old records existed (Leptodon cayanensis). The records were obtained during surveys conducted at five sites within the Cuña Boscosa. Although the records are from localities within the Humid Chaco ecoregion, in most cases (B. brachyurus, L. cayanensis, N. albicollis), these species are associated with humid forests more typical of the Paraná biogeographic province. In contrast, during its stay in the area during the breeding season, I. inornata seems to utilize the edges of xerophytic forests characteristic of the Chaco. These records contribute to the knowledge of bird diversity in the southernmost part of the Humid Chaco, in the province of Santa Fe, and enhance the region's value for its contribution to the conservation of the Gran Chaco.

Macroinvertebrates of semi-arid mountain rivers of San Luis (Argentina): basis for ecological assessment

2025-12-16T08:02:24-03:00

River systems in arid and semi-arid regions are subject to hydrological stress due to precipitation variability, extreme events, and increasing anthropogenic pressure. This study aimed to characterize the composition of benthic macroinvertebrate assemblages in mountain streams of San Luis, Argentina, to establish a reference community as the basis for developing a biological index adapted to arid and semi-arid ecosystems. Five rivers were sampled during high- and low-flow periods at sites classified as reference or impaired, according to impact level, physicochemical parameters, and ecological assessment. Reference sites were selected using the CERA protocol, complemented by physicochemical variables (pH, conductivity, temperature, dissolved oxygen, BOD5, turbidity, nitrates, and phosphates) integrated into the ISQA index. Macroinvertebrates were collected using D-frame and Surber nets, totaling 86 samples identified to family level. Diversity metrics and the IBSSL index were calculated. Reference sites showed high CERA scores (94–100), good water quality according to ISQA, and low impact based on IBSSL, along with greater richness and diversity compared to impaired sites. Discriminant analysis clearly separated both site types and highlighted families from Ephemeroptera, Trichoptera, and Diptera as key ecological indicators. The reference community defined in this study provides a solid foundation for developing future bioindicator tools tailored to semi-arid regions, with potential applications in monitoring, management, and conservation programs for fluvial ecosystems in the Pampean mountain ranges.

Whip spiders (Amblypygi: Phrynidae) from Islas de la Bahia Department, Honduras

2025-12-16T08:02:23-03:00

The department of Bay Islands, in the Caribbean region of Honduras,
harbors no fewer than five amblypygid species (Phrynidae: Paraphrynus
1 sp., Phrynus 4 spp.), although two of them, belonging to the genus
Phrynus, could not be identified with certainty. The presence of Phry-
nus damonidaensis Quintero, 1981, is confirmed on the Swan Islands,
and the presence of Paraphrynus maya Armas, Trujillo & Agreda, 2017
is reported for the first time in this Honduran department, as well as
Phrynus palenque Armas, 1996 in Guanaja. In addition, based on an
observation made in 2010 and published on iNaturalist, the possible
presence of Phrynus parvulus Pocock, 1902, or a morphologically similar
species, is suggested in Cayo Cochino Menor

Mammals richness and abundance in herbaceous and woody corridors of an agroecological farm in the Tandilia Range System

2025-12-16T08:02:15-03:00

The expansion of agroecosystems in Buenos Aires Province has drastically reduced natural grasslands, negatively affecting biodiversity. In this context, biological corridors—such as crop margins and tree strips—can function as habitats and connectivity pathways for wildlife. This study recorded and compared mammal richness and abundance in herbaceous and woody corridors within an agroecological farm in the Tandilia Range System. Six corridors were sampled during 2017–2018 using Sherman and Tomahawk live traps, complemented by track and sighting records. A total of 119 small mammals belonging to six species were captured, with Oxymycterus rufus being the most abundant. Additionally, seven species of medium and large mammals were recorded through tracks, burrows, and feces. A higher abundance of small mammals was observed in herbaceous corridors, while no significant differences were found in species richness or community composition between vegetation types. This study provides the first records of mammals in corridors of an agroecological agroecosystem in the Tandilia Range and highlights the importance of conserving these linear habitats to maintain mammal diversity in agricultural landscapes.

Discovery of a population of Liolaemus pseudolemniscatus Lamborot and Ortiz, 1990 (Squamata: Liolaemidae) to the west of Santiago, Chile: new southern latitudinal limit

2025-09-01T10:31:50-03:00

A population of Liolaemus pseudolemniscatus associated with a hill located west of Santiago city, Metropolitan Region, Chile, closely linked to the Coastal mountain range in the central zone of the country, is documented for the first time. Previously, this endemic lizard had only been recorded in the foothills of the Andean mountain range, about 35 km east of the location of this report, with no records in the intermediate valley. On the other hand, the closest record to the north, outside of the Andes, is located more than 100 km away, in the northern Valparaiso Region. This record fills the gaps in distributional information that existed for this species in central Chile, and its complete extension can be appreciated.

Verified records of Urania leilus (Lepidoptera: Uraniidae) for Catamarca Province, Argentina

2025-09-01T10:31:49-03:00

Urania leilus (Lepidoptera: Uraniidae) is a diurnal moth distinguished
by its velvet black coloration and iridescent green bands. Its primary
distribution includes the Amazon Basin and other tropical areas, but
recent reports document occurrences in Argentina, including new re-
cords from Catamarca Province. The study presents the first confirmed
observations of U. leilus in urban and peri-urban environments in cen-
tral and western Catamarca —specifically in San Fernando del Valle de
Catamarca and Andalgalá— between 2023 and 2025. All individuals
were photographed, georeferenced, and observed under varied envi-
ronmental conditions, perched on plant species unrelated to the genus
Omphalea, the only known larval host. The absence of Omphalea in
the region suggests that these individuals are accidental migrants or
erratic dispersers, with no evidence of established populations. Potential
causes include unintentional transport, wind dispersal, or environmental
changes. The study also integrates citizen science records and describes
the arid phytogeographic context of the sampled sites. These findings
highlight the importance of collaboration between formal science and
local observers in improving faunal inventories. Additionally, U. leilus
is proposed as a potential bioindicator species, due to its speacialized
diet and migratory behavior. Finally, the lack of conservation status for
this species in the IUCN and national agencies underscores the urgent
need for more systematic research, especially in underexplored regions
such as northwestern Argentina.

First records of the praying mantis Empusa fasciata Brulle, 1832 (Mantodea: Empusidae) from the Republic of Kosovo with notes on other putative Mantodea species previously erroneously recorded

2025-09-01T10:31:42-03:00

Empusa fasciata Brulle, 1832 is reported from the Republic of Kosovo based on specimens from multiple localities. This work fills an important zoogeographical gap, as this otherwise widespread species was hitherto formally unknown for Kosovo. Historical records of other mantids are discussed, and the formal list now consists of two species.

Tridentiger bifasciatus (Gobiiformes, Gobiidae): new record of an exotic species in the Río Negro, Argentina

2025-11-18T10:50:27-03:00

Biological invasions represent one of the main causes of biodiversity loss,
second only to habitat destruction. These exotic species alter natural
ecosystems and generate environmental impacts. The goby Tridentiger
bifasciatus, native to the northwestern Pacific of Asia, has expanded
its distribution in recent decades. After being recorded in California,
North America, and more recently in Belgium and Argentina (Pehu-
en-Co). The aim of this study is to report the first record of the exotic
goby Tridentiger bifasciatus in the Negro River, Argentina. The finding
took place in the Negro River (-40.803579 S; -62.985768 W), in March
2025. Two specimens of 53 and 84 mm total length were collected
from the riverbank, later analyzed morphologically, and preserved in the
LaByCAA-UNRN collection. The specimens showed distinctive diagnostic
traits, such as dark longitudinal bands, tricuspid teeth, and fused pelvic
fins. The presence of T. bifasciatus in the Negro River may be linked to its
expansion from Pehuen-Co (Buenos Aires). Its generalist nature, broad
diet, and tolerance to low salinity favor its establishment and spread.
Considering that almost half of the fish species in the Negro River are
introduced, this record highlights a concerning increase in the invasion
of exotic fishes, with potentially negative consequences for regional
biodiversity.

Presence of Hippocampus patagonicus (Syngnathiformes: Syngnrathidae) in the external estuary of the Negro River, Río Negro Province, Argentina

2025-12-16T08:02:21-03:00

he order Syngnathiformes includes pipefishes and seahorses, with Hi-
ppocampus being the only genus comprising the latter. They exhibit a
global distribution across tropical and temperate regions. Seahorses
face multiple anthropogenic threats, which have led many species to
be classified as Vulnerable by the IUCN. This study reports the presence
of Hippocampus patagonicus in the outer estuary of the Negro River,
Argentina. A stranded female specimen of H. patagonicus was docu-
mented on the coast of the outer Negro River estuary. As the specimen
was incomplete, only the following morphometric measurements were
recorded: trunk length, dorsal fin base length, pectoral fin base length,
head length, snout length, postorbital distance, and orbital distance.
The meristic characters used included: number of trunk rings, number
of anal fin rays, number of pectoral fin rays, and number of dorsal fin
rays. Based on the morphometric values obtained, the specimen was
identified as a small-sized female. This record is significant given the
species’ vulnerable status and the fact that the population in San An-
tonio Bay has declined by approximately 90% over the past 30 years.
Furthermore, it is essential to intensify research efforts in the area to
determine whether this finding represents an isolated occurrence or
evidence of an established population within the study site.

New location and first nesting records of the Psarocolius decumanus (Passeriformes: Icteridae) in Catamarca, Argentina

2025-12-16T08:02:13-03:00

The Icteridae family comprises 25 species in Argentina, one of them
being the Crested Oropendola (Psarocolius decumanus). This species is
characterized by its large size, compared to other passerines, and its
gregarious nature. A clear southward expansion of its populations has
been recorded across northwestern Argentina, and its presence has been
documented so far in provinces such as Misiones, Corrientes, Formosa,
Jujuy, Salta, Tucumán, and recently in Catamarca, where it has been
sighted twice in the same location. In this paper we document the pre-
sence of four individuals and the first nesting record for the province of
Catamarca, in La Viña (Paclín department), areas of the Pedemontane
Forest of the Southern Yungas. These data provide valuable information
regarding the establishment of P. decumanus as a resident species in
the province of Catamarca.