The southernmost range limit for the hidden angelshark Squatina occulta

Background: Angelsharks (Genus Squatina) are distributed in the southern Southwest Atlantic Ocean between southeastern Brazil and central Patagonia. The endangered hidden angelshark Squatina occulta is reported in the literature as ranging from Espírito Santo, Brazil to Southern Uruguay. Its presence in Argentine waters has been suspected but not verified so far. This study describes and analyzes a specimen of S. occulta found in Puerto Quequén 38° 40′S - 58° 50′W, Buenos Aires Province, Argentina. Results: An immature male of 578 mm total length and 1,450 g was collected from commercial landings of the bottom trawl fishery of Puerto Quequén. The specimen exhibited the coloration pattern, dermal denticle distribution, and tooth formula characteristic of S. occulta. Conclusions: Squatina guggenheim and S. argentina are already known to occur off Puerto Quequén. The present finding confirms the presence of a third species of angelshark in Argentina and constitutes the southernmost record of S. occulta.Fil: Estalles, María Lourdes. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencia Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales ; ArgentinaFil: Chiaramonte, Gustavo Enrique. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales ; ArgentinaFil: Faria, Vicente V.. Universidade Federal do Ceará; BrasilFil: Luzzatto, Diego. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales ; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencia Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; ArgentinaFil: Díaz de Astarloa, Juan Martín. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencia Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; Argentin

Testing macroecological hypotheses in sandy beach populations: the wedge clam Donax hanleyanus in South America

Large-scale spatial and temporal variability in environmental conditions may result in differences in life-history traits, population demography, and abundance of sandy-beach species. We analyzed the effects of salinity, chlorophyll a (chl a), and sea surface temperature (SST) on population parameters of the wedge clam Donax hanleyanus from 75 South American sandy beaches covering a 15° latitudinal range. Generalized modeling results showed that betweenbeach differences in abundance, population structure, growth performance, productivity, mortality, and individual shell mass were mainly explained by salinity fluctuations, with chl a and SST as secondary contributors, overriding, in most cases, local habitat features (Dean's parameter, grain size, slope). Our results provide valuable insights into macroscale ecological processes, setting a basis to delineate conservation guidelines at large spatial scales that respond to the potential effects of climate variability and change on sandy beach populations.Fil: Risoli, María Cielo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; ArgentinaFil: Piola, Alberto Ricardo. Ministerio de Defensa. Armada Argentina. Servicio de Hidrografía Naval; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Defeo, O.. Universidad de la República. Facultad de Ciencias; UruguayFil: Luzzatto, Diego. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto Andino Patagónico de Tecnologías Biológicas y Geoambientales. Universidad Nacional del Comahue. Instituto Andino Patagónico de Tecnologías Biológicas y Geoambientales; ArgentinaFil: Celentano, E.. Universidad de la República. Facultad de Ciencias; UruguayFil: Lomovasky, Betina Judith. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Subsede Instituto Nacional de Investigación y Desarrollo Pesquero; Argentin

A new method to assess natural history traits of seahorses

We developed a non-invasive method to record multiple measurements and data of seahorses in situ. We tested this development over individuals from the southernmost population of Hippocampus patagonicus at San Antonio Bay, northern Patagonia, Argentina. We captured individuals along transects of 1000m parallel to the coast, determined their geographical position, sex and maturity stage. We fastened each by its trunk to a scaled measuring board with an elastic band and took a photograph at a distance of 50 cm (to measure the standard length) and a close-up one of the head to individually identify the specimens by face recognition later at the lab. We obtained a left and right set of photographs of every seahorse. After this manipulation (1-2 minutes), we released the animals and recorded the escaping behavior: 1. fast escape; 2. attachment to a near holdfast or 3. catatonic behavior. 94% of the animals recovered immediately after manipulation (1 and 2 behavior). We analyzed the photographs and identified individuals by face recognition taking into account bright spots, head contour and sex. We compared over 767 photographs and were able to recognize 112 individuals recaptured. We also compared this new technique of face recognition to the standard VIE tagging method in a total of 100 animals. Both techniques showed similar effectiveness recognizing individuals. In addition, this new method resulted inexpensive and not invasive while requiring standard equipment and training.Fil: Luzzatto, Diego. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; ArgentinaSingBio2021GuangzhouChinaSouth China Sea Institute of Oceanolog

A novel non-invasive efficient photography-based technique for length measuring and individual identification of seahorses

Abstract This study aimed to develop a non-invasive and efficient method for measuring and identifying individual seahorses (Hippocampus patagonicus) in their natural habitat. A total of 976 seahorses were captured and photographed on a measuring board to obtain standard length (L s) measurements. Head photographs were also taken for individual recognition, and a set of 100 seahorses were tagged with visible implant elastomers (VIE) to verify the correspondence between photograph recognition and the applied tags. The analysis showed no significant difference between left and right L s measurements. The unique pattern of white dots on the heads served as individual fingerprints, consistent with VIE tagging. The recapture rate was 12%, with 89 individuals observed multiple times. Two distinct growth patterns were identified: males exhibited higher growth rates and a negative correlation with L s compared to females. Released seahorses exhibited significantly different behaviors that were related to their sizes (L s). Smaller seahorses tended to swim slowly towards nearby holdfasts, while larger seahorses escaped further or remained rigid before grasping a holdfast. The proposed methodology allowed for estimating individual seahorse growth rates, and the measurements were objective and precise. The results were obtained through quick and minimally invasive manipulation of the observed individuals

Ex-situ growing out of early stages of wild seahorses: Envisioning conservation options for threatened populations

Rafting has been proposed as a dispersive mechanism for some species of seahorses. Juvenile Hippocampus patagonicus rafting on the sea surface have been reported. This life stage has high mortality in nature due to ecological and environmental factors usually affecting juvenile planktonic teleosts (e.g. predation). In this study, 50 juvenile seahorses were captured while rafting at the beginning of the reproductive season (December). They were grown out under a standard protocol in a recirculating aquaculture system for 120 days until they reached maturity. During this period, only three seahorses died (6%). Mature seahorses were 65 ± 7 mm average height and showed variable coloration and pigmentation pattern (n = 47; 94%). The availability of juvenile seahorses during the reproductive season and their high survival performance ex situ highlight the feasibility of developing protocols in which juvenile seahorses serve as a novel source of broodstock.Fil: Luzzatto, Diego. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; ArgentinaFil: Estalles, María Lourdes. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; Argentina. Instituto de Formacion Docente Continua de San Antonio Oeste.; Argentin

Hippocampus patagonicus

Hippocampus patagonicus is a coastal species of seahorse that inhabits waters from northeastern Brazil to Chubut, Argentina. The major habitats occupied by the species include seagrasses, macroalgae, and sheltered areas with sessile invertabrates. The species is threatened by habitat degradation and loss from coastal development and destructive fishing practices, targeted exploitation, and by being caught extensively as bycatch in shrimp trawl fisheries. Based on declining habitat quality, extent of occurrence, and declines reported by fishers, it is inferred that the population has undergone a decline of at least 30%. Therefore Hippocampus patagonicus is listed as Vulnerable under criterion A2cd.Fil: Jasmine, Wei. Project Seahorse; CanadáFil: Estalles, María Lourdes. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencia Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; ArgentinaFil: Riley, Pollom. Project Seahorse; CanadáFil: Luzzatto, Diego. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencia Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; Argentin

Comment on ‘Genetic evidence and new morphometric data as essential tools to identify the Patagonian seahorse Hippocampus patagonicus (Pisces, Syngnathidae) by González et al. (2014)’

The aim of the contribution of González et al. (2014) was to improve the original description and validate the taxonomic status of the Patagonian seahorse Hippocampus patagonicus Piacentino & Luzzatto 2004. To do so, the authors analysed morphological and genetic characteristics of seahorses of San Antonio Bay, Argentina. Concerning both issues, the information presented lacks validity and originality.Fil: Luzzatto, Diego. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencia Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; ArgentinaFil: Estalles, María Lourdes. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencia Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; ArgentinaFil: Díaz de Astarloa, Juan Martín. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencia Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; Argentin

Rafting seahorses: The presence of juvenile Hippocampus patagonicus in floating debris

A total of 477 juvenile Hippocampus patagonicus recorded in 80 sampling events were detected rafting on the surface during high tide at San Antonio Bay, northern Patagonia, Argentina. If rafting juveniles drift long distances beyond their original populations, they have the potential to form new populations, which may explain the wide distribution of H. patagonicus.Fil: Luzzatto, Diego. Universidad Nacional del Comahue. Instituto de Biologia Marina y Pesquera Almirante Storni; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Estalles, María Lourdes. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional del Comahue. Instituto de Biologia Marina y Pesquera Almirante Storni; ArgentinaFil: Diaz de Astarloa, Juan Martin. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Mar del Plata. Instituto de Investigaciones Marinas y Costeras; Argentin

QUANTITATIVE STUDY OF NEURONAL DEGENERATION INDUCED BY RICINUS TOXIN AND CRUSH OF POSTGANGLIONIC NERVES IN THE CILIARY GANGLION OF QUAIL

The effects of Ricinus toxin on the neurons of the ciliary ganglia were investigated in the quail. The neuronal death and the morphological alterations of the ganglionic cells were assessed following injection of the toxin in the anterior chamber of the eye or after application of the toxin on the postganglionic nerves at a crush site. A 45% loss of choroid neurons without loss of ciliary neurons was observed after postganglionic nerve crush alone. Injection of the toxin in the anterior chamber of the eye led to a selective loss of ciliary neurons (38%). Application of the toxin to the crushed postganglionic nerves led to a loss from both neuronal populations (40% of total neurons). This work indicates that different procedures result in selective lesion of the different neuronal populations in the ciliary ganglion

The presence of the seahorse Hippocampus patagonicus in the Argentine Sea based on the cytochrome b sequence of mitochondrial DNA

This study aimed at sequencing the mitochondrial cytochrome b gene (cyt b) of seahorses morphologically identified as Hippocampus patagonicus Piacentino & Luzzatto, 2004 from the two known localities where the species occur in the Argentine Sea (San Antonio Oeste and Mar del Plata). Based on the lack of substitutions within cyt b found between the individuals of both localities, the geographical range of H. patagonicus was extended up to the Northern limit of the Argentine Sea. A phylogenetic analysis comparing the cyt b sequences of Hippocampus species revealed that H. patagonicus together with H. hippocampus and H. erectus belong to a monophyletic group of species. The comparison of the cyt b sequence of Hippocampus cf. erectus from Southern Brazil with that one of H. patagonicus resulted in scarce differences. This could suggest the presence of H. patagonicus in southern Brazil, although further investigation is needed to resolve the taxonomic status of H. erectus in the South Western Atlantic.Fil: Luzzatto, Diego. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; ArgentinaFil: Sieira, Rodrigo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Bioquímicas de Buenos Aires. Fundación Instituto Leloir. Instituto de Investigaciones Bioquímicas de Buenos Aires; ArgentinaFil: Pujol, Maria Gabriela. Museo Municipal de Ciencias Naturales Lorenzo Scaglia; ArgentinaFil: Díaz de Astarloa, Juan Martín. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; Argentin