Abstract Nototheniidae is the most numerous family of notothenioids and, although they are mainly Antarctic, they are also well represented in Patagonian waters. In both Antarctic and sub-Antarctic waters, they adopt a wide variety of reproductive strategies. In Antarctic waters they usually have a biennial reproductive cycle, whereas in sub-Antarctic ones, they reproduce annually or biannually. In the intertidal zone of central Patagonia the most abundant nototheniid fish is Patagonotothen cornucola and, despite this, there is little information about their biology. The aim of this work was to study its reproductive cycle in a rocky intertidal coast of Argentine Patagonia by means of histological and morphological analyses. Samples were collected monthly at two intertidal sites in the San Jorge Gulf. Condition factor, gonadosomatic and hepatosomatic indexes were calculated and thin sections of gonads were stained with one-step trichrome to determine gonadal stages. Relative and potential fecundity were also estimated. Males and females mature synchronously and reach maximum gonadosomatic index between July and August. In females the hepatosomatic index increases synchronously with gonadosomatic index, while in males it remains constant throughout the cycle. It is concluded that P. cornucola has an annual reproductive cycle and that spawning occurs in winter. Maximum potential fecundity is approximately 27,095 oocytes in a 11.7 cm female and it increases with size.

Resumen La familia Nototheniidae es la más numerosa entre los nototénidos y, a pesar de ser principalmente Antárticos, están muy bien representados en aguas patagónicas. Desde la Antártida hasta las aguas de Sudamérica, han adoptado una gran variedad de estrategias reproductivas. Los peces antárticos suelen tener un ciclo reproductivo bienal mientras que en aguas sub-antárticas los nototénidos pueden reproducirse anualmente o bianualmente. En la zona intermareal de la Patagonia central, el pez más abundante es Patagonotothen cornucola y, a pesar de esto, hay poca información sobre su biología. Por esto, el objetivo principal de este trabajo fue estudiar su ciclo reproductivo en la zona intermareal rocosa usando métodos histológicos y morfológicos. Las muestras fueron recolectadas mensualmente en dos sitios intermareales en el Golfo San Jorge, y se calculó el factor de condición, índices hepatosomáticos y gonadosomáticos y se realizaron cortes histológicos de las gónadas que fueron teñidas con tricrómico de un tiempo para determinar los estadios gonadales, además se estimó la fecundidad potencial y relativa. Se determinó que machos y hembras maduran sincrónicamente alcanzando los valores máximos de índices gonadosomáticos entre julio y agosto. En las hembras el índice hepatosomático aumenta simultáneamente con el gonadosomático mientras que en machos se mantiene constante durante todo el ciclo. Se concluye que P. cornucola tiene un ciclo reproductivo anual y que el desove ocurre en el invierno. La fecundidad potencial máxima fue de 27.095 oocitos en una hembra de 11,7 cm y se incrementa con la talla.

Abstract Introduction: Echinoderms are dominant in terms of abundance and diversity; particularly asteroids play an important role in Antarctic benthic communities. Objective: The aim of the present work was to review the bathymetric distribution, specific composition, occurrence and species richness of asteroid species inhabiting South Orkney, South Shetland and Palmer Archipelago, located in the Antarctic Peninsula. Aspects of the developmental patterns of the species found are also included. Methods: We used data acquired during the 2012 and 2013 Antarctic Summer Campaigns aboard the Oceanographic Vessel “Puerto Deseado”. Sampling stations were located in three archipelagos located in the Antarctic Peninsula: South Orkney (SO), South Shetland (SS) and Palmer Archipelago (PA). A total of 28 fishing hauls were made and 436 individuals were photographed and processed. The maximum radius (mm) of each individual, the macroscopic characteristics of the gonads and the presence of embryos were registered. A review of the taxonomic status, bathymetric and geographical distribution area of the sampled species was carried out based on bibliographic records and databases. A hierarchical grouping was used to analyze species composition among the different areas. Results: Asteroids were obtained in all sampling stations (occurrence: 100 %) between 52.7 and 987 m depth. 21 species were recorded, the bathymetric distribution was not broadened in any of them, and the geographical distribution area of six species was expanded. Species richness was equal in SS and PA and higher than in SO, coinciding with the presence of two regional groups with a similar faunal composition. Seventy-two percent of the recorded species present pelagic development (planktotrophic larvae = 17 %, and lecithotrophic larvae = 55 %) and 28 % non-pelagic development (retained larvae = 17 %, and direct development = 11 %). Conclusions: In the three archipelagos, the majority development pattern was pelagic with lecithotrophic nutrition. All the species found in this study are shared with the sub-Antarctic region, highlighting the importance of the Malvinas Current in the dispersal of species from Antarctica.

Resumen Introducción: Los equinodermos son dominantes en términos de abundancia y diversidad; particularmente los asteroideos presentan un importante rol en las comunidades bentónicas antárticas. Objetivo: El objetivo del presente trabajo fue revisar la distribución batimétrica, composición específica, ocurrencia y riqueza de especies de asteroideos que habitan en los archipiélagos Orcadas del Sur, Shetland del Sur y Archipiélago de Palmer, ubicados en la Península Antártica. A su vez, detallar aspectos de los patrones de desarrollo de las especies halladas. Métodos: Utilizamos la información adquirida durante Campañas Antárticas de Verano 2012 y 2013, a bordo del Buque Oceanográfico “Puerto Deseado”. Las estaciones de muestreo se ubicaron en tres archipiélagos localizados en la Península Antártica: Orcadas del Sur (OS), Shetland del Sur (SS) y Archipiélago de Palmer (AP). Se realizaron 28 lances de pesca y se fotografiaron y procesaron 436 individuos. Se determinó el radio mayor (mm) de cada individuo, las características macroscópicas de las gónadas y la presencia de embriones. Se realizó una revisión del estatus taxonómico y de la distribución batimétrica y del área de distribución geográfica de las especies muestreadas basándonos en registros bibliográficos y bases de datos. Se utilizó una agrupación jerárquica para analizar la composición de las especies entre las diferentes áreas. Resultados: En todas las estaciones de muestreo se obtuvieron asteroideos (ocurrencia: 100 %) entre 52.7 y 987 metros de profundidad. Se registraron 21 especies, de las cuales no se modificó la distribución batimétrica de ninguna de ellas, pero se amplió el área de distribución geográfica de seis. La riqueza de especies fue igual en SS y AP, y mayor que en OS, coincidiendo con la presencia de dos grupos regionales con una composición faunística similar. El 72 % de las especies registradas presentan desarrollo pelágico (larva planctotrófica = 17 % y larva lecitotrófica = 55 %) y el 28 % desarrollo no pelágico (larva retenida = 17 % y desarrollo directo = 11 %). Conclusiones: En los tres archipiélagos el patrón de desarrollo mayoritario fue el pelágico con nutrición lecitotrófica. La totalidad de las especies halladas en el presente trabajo son compartidas con la región subantártica, destacándose la importancia de la Corriente de Malvinas en la dispersión de las especies desde Antártida.

Resumo Aspectos da biologia reprodutiva de Donax striatus foram estudados. Os indivíduos foram coletados mensalmente de fevereiro de 2021 a janeiro de 2022 na praia Gado Bravo, no município de Tibau do Norte, estado do Rio Grande do Norte, Brasil. Donax striatus é uma espécie dióica sem dimorfismo macroscópico externo (na concha) ou interno (gônadas). Assim, é necessário um exame microscópico das células reprodutivas. Para a caracterização dos estágios de desenvolvimento gonadal e determinação do tamanho na primeira maturidade sexual (L50), 30 espécimes foram selecionados mensalmente entre fevereiro de 2021 e janeiro de 2022 e submetidos ao processamento histológico. O índice de Condição (IC) de cada indivíduo foi estimado e as variações mensais foram estatisticamente avaliadas. O tamanho de primeira maturação (L50) foi estimado em 14,2 mm de comprimento de concha. Para promover a conservação da espécie, recomenda-se a captura de indivíduos maiores que 14,2 mm. Os menores índices de condição foram encontrados na estação seca, com maior ocorrência de organismos em fase de eliminação e exibindo reorganização do tecido gonadal. Índices maiores foram encontrados no período chuvoso, com presença de indivíduos maduros. A natureza contínua da gametogênese em Donax stritatus reflete a influência das chuvas na região. Machos e fêmeas apresentam pico de eliminação de gametas com pausas durante o ano, mas com presença de indivíduos em maturação e eliminação ao longo do ano. Como a mariscagem visando Donax striatus é excessiva na Praia de Gado Bravo, no estado do Rio Grande do Norte, espera-se que os resultados do presente estudo possam contribuir para o estabelecimento de medidas de manejo da atividade e estratégias de conservação da espécie. estudados 202 Bravo Norte Brasil concha gônadas. gônadas . (gônadas) Assim reprodutivas L50, L50 L , 3 histológico IC (IC avaliadas (L50 142 14 2 14, recomendase recomenda se seca chuvoso maduros região ano esperase espera 20 (gônadas L5 (L5 1 (L

Abstract Aspects of the reproductive biology of Donax striatus were studied from individuals collected from Gado Bravo Beach in the municipality of Tibau do Norte, state of Rio Grande do Norte, Brazil. Donax striatus is a dioic species without external (on the shell) or internal (gonads) macroscopic dimorphism. Thus, a microscopic examination of the reproductive cells is necessary. For the characterization of the gonadal development stages and determination of the size at first sexual maturity (L50), 30 specimens were selected monthly between February 2021 and January 2022 and submitted to histological processing. The condition index (CI) of each individual was estimated and monthly variations were statistically assessed. The size at first maturity (L50) was estimated to be 14.2 mm in shell length. To foster conservation of the species, catches of individuals larger than 14.2 mm is recommended. The lowest condition indices were found in the dry season, with a greater occurrence of organisms in the elimination stage and exhibiting gonad tissue reorganization. Higher indices were found in the rainy season, with the presence of mature individuals. The continuous nature of gametogenesis in Donax stritatus reflects the influence of rainfall in the region. Males and females have peak gamete elimination with pauses during the year, but with the presence of maturing and eliminating individuals throughout the year. As shellfish gathering targeting Donax striatus is excessive on Gado Bravo Beach in the state of Rio Grande do Norte, it is hoped that the results of the present study can contribute to the establishment of management measures for the activity and conservation strategies for the species. Norte Brazil gonads (gonads dimorphism Thus necessary L50, L50 L , 3 202 processing CI (CI assessed (L50 142 14 2 14. length recommended season reorganization region year L5 20 (L5 1 (L

Abstract Callithrix kuhlii is present in forest mosaics, edge habitats, and abandoned fields in the Atlantic Forest. In Bahia and Minas Gerais. This study aimed to identify helminths from C. kuhlii and relate them to the clinical data, weights, and indices of the liver and gonads. Necropsies were performed on 13 adult marmosets that were run over on the BA-001 highway. A principal component analysis (PCA) was conducted to describe the relationships between the variables investigated. Fifty-one helminths were collected from 30.77% (4/13) of the marmosets analyzed. Helminths were classified based on their morphological and morphometric characteristics. Primasubulura jacchi (Marcel, 1857), Platynosomum illiciens (Dougherty, 1946), and Prosthenorchis confusus (Dougherty, 1946) were the species identified, with prevalence rates of 7.69%, 7.69%, and 15.38%, respectively. In addition, this is a new host record of P. confusus. The two main axes of the PCA explained a high variability (PCA=67.7%), indicating reduced weight and indices of the organs of parasitized animals. This study expands the knowledge on parasites of C. kuhlii and its vulnerability to parasites, contributing to constructing an epidemiological profile of environmental health. mosaics habitats Forest Gerais C data weights gonads 1 BA001 BA 001 BA-00 highway (PCA investigated Fiftyone Fifty one 3077 30 77 30.77 4/13 413 4 (4/13 analyzed characteristics Marcel, Marcel (Marcel 1857, 1857 , 1857) Dougherty, Dougherty (Dougherty 1946, 1946 identified 769 7 69 7.69% 1538 15 38 15.38% respectively addition P PCA=67.7%, PCA677 PCA=67.7% 67 (PCA=67.7%) animals health BA00 00 BA-0 307 3 30.7 4/1 41 (4/1 185 194 76 6 7.69 153 15.38 PCA67 PCA=67.7 (PCA=67.7% BA0 0 BA- 30. 4/ (4/ 18 19 7.6 15.3 PCA6 PCA=67. (PCA=67.7 (4 7. 15. PCA=67 (PCA=67. ( PCA=6 (PCA=67 PCA= (PCA=6 (PCA=

Resumo Callithrix kuhlli é encontrado em mosaicos florestais, habitats de borda e campos abandonados da Mata Atlântica. Na Bahia e Minas Gerais. O objetivo do trabalho foi identificar helmintos recuperados de C. kuhlli e relacioná-los aos dados clínicos, pesos e índices provenientes do fígado e das gônadas. Foram realizadas necropsias em 13 saguis adultos atropelados na rodovia BA-001 e realizada uma análise de componentes principais (PCA), para descrever as relações entre as variáveis. Recuperou-se 51 helmintos em 30,77% (4/13) dos saguis analisados. A classificação dos helmintos ocorreu por meio das características morfológicas e morfométricas, sendo Primasubulura jacchi (Marcel, 1857), Platynosomum illiciens (Dougherty, 1946) e Prosthenorchis confusus (Dougherty, 1946) as espécies identificadas, com prevalências de 7,69%; 7,69% e 15,38% respectivamente. Ainda, P. confusus apresenta um novo registro de hospedeiro. Já os dois eixos principais da PCA explicaram alta variabilidade (PCA=67,7%), verificando nos animais parasitados uma redução do peso e índices provenientes dos órgãos. Este trabalho amplia o conhecimento sobre parasitos do C. kuhlli e o grau de vulnerabilidade aos parasitas, contribuindo para uma possível construção de perfil epidemiológico da saúde ambiental. florestais Atlântica Gerais C relacionálos relacioná los clínicos gônadas 1 BA001 BA 001 BA-00 PCA, , (PCA) variáveis Recuperouse Recuperou se 5 3077 30 77 30,77 4/13 413 4 (4/13 analisados morfométricas Marcel, Marcel (Marcel 1857, 1857 1857) Dougherty, Dougherty (Dougherty 1946 identificadas 769 7 69 7,69 1538 15 38 15,38 respectivamente Ainda P hospedeiro PCA=67,7%, PCA677 PCA=67,7% 67 (PCA=67,7%) órgãos parasitas ambiental BA00 00 BA-0 (PCA 307 3 30,7 4/1 41 (4/1 185 194 76 6 7,6 153 15,3 PCA67 PCA=67,7 (PCA=67,7% BA0 0 BA- 30, 4/ (4/ 18 19 7, 15, PCA6 PCA=67, (PCA=67,7 (4 PCA=67 (PCA=67, ( PCA=6 (PCA=67 PCA= (PCA=6 (PCA=

Abstract Reproductive control is one of the biggest challenges in tilapia production and triploidy was developed as an alternative to sterilization. In general, polyploids present chromosomal instability but for triploid Nile tilapia it has yet to be reported. This study evaluated the chromosomal instability from juveniles to adulthood, growth performance and gonadal status of tilapia hatched from eggs submitted or not to heat shock for triploid induction. Nile tilapia oocytes were fertilized (1,476 oocytes), half of the eggs were subjected to a four-minute shock in 41 °C water four minutes after fertilization and the other half were not (Control group). The eggs were incubated (at 27°C) and 160 larvae from the treated group hatched and survived after yolk sac absorption. The determination of ploidy was performed by flow cytometry at 85th (juveniles) and 301st (adults) days of age post yolk sac absorption. At the time of the first cytometry analysis there were 73 surviving juveniles from the treated group, and only 14 were confirmed triploid. However, at the analysis of adult ploidy, one out of 8 surviving adult tilapias from the 14 confirmed triploid juveniles remained triploid. Gonadal histology showed that the non-remaining triploids continued to produce gametes. The growth performance of triploid tilapia was initially superior to that of diploid tilapia during the juvenile phase, but similar in adults. Once the chromosome sets are lost and the tilapias become diploid again, at least in tissues with a high proliferation rate, such as the hematopoietic tissue that was analyzed (and possibly in gonads), all possible advantages of triploids are probably lost. Thus, our results suggest that, due to genomic instabilities, the triploid generation of tilapia has low efficiency. sterilization general reported adulthood induction 1,476 1476 1 476 (1,47 oocytes, , oocytes) fourminute minute 4 C Control group. . group) 27°C 27C 27 16 absorption th (juveniles st adults (adults 7 However nonremaining non remaining gametes phase again rate gonads, gonads gonads) Thus instabilities efficiency 1,47 147 47 (1,4 2 1,4 (1, 1, (1 (

Abstract This study aimed to investigate the effect of temperature on gonadal differentiation, growth, survival, and sex ratio of Leporinus friderici reared at 25 °C or 29 °C from 50 to 240 days after eclosion (DAE) in a water recirculation system. A total of 110 fish at 50 DAE (6.7 ± 0.1 cm and 6.1 ± 0.3 g) were equally and randomly distributed in 10 boxes (90 L) (11 fish/box, 5 boxes/temperature). One fish from each experimental unit was randomly sampled at 50, 70, 90, 110, 130, 150, 170, 190, 210 and 240 DAE. Female gonadal differentiation started at 150 DAE (11.4 ± 0.0 cm and 16.4 ± 0.0 g) at 25 °C and at 170 DAE (10.7 ± 0.7 cm and 27.7 ± 8.5 g) at 29 ºC, while testes differentiation only occurred at 29 °C from 190 DAE (12.1 ± 0.0 cm and 38.0 ± 0.0 g). Of 50 fishes sampled in each condition, 17 (12 females and five males) and three (three females) displayed gonadal differentiation at 29 °C and 25 °C, respectively. Final biometric values at 29 °C were twice those obtained at 25 °C, reaching 13.9 ± 0.65 cm and 57.3 ± 10.12 g versus 11.2 ± 0.39 cm and 28.5 ± 2.95 g, respectively. While temperature clearly influenced gonadal differentiation and growth, it had inconclusive effects on sex ratio. The higher temperature (29 °C) has direct implications for the production of this species, as it accelerates growth without causing mortality. survival 2 C 24 (DAE system 11 6.7 67 6 7 (6. 01 0 1 0. 61 6. 03 3 90 (9 L (1 fishbox box fish/box boxes/temperature. boxestemperature boxes/temperature . boxes/temperature) 70 130 21 15 11.4 114 4 (11. 00 164 16 16. 10.7 107 (10. 07 277 27 27. 85 8 8. ºC 19 12.1 121 12 (12. 380 38 38. g. condition males respectively 139 13 9 13. 065 65 0.6 573 57 57. 1012 10.1 112 11. 039 39 285 28 28. 295 95 2.9 (2 species mortality (6 ( 10. (10 12. 06 101 2.

Abstract. The reproductive and larval performance of Pteria sterna associated with anomalous environmental factors was evaluated, testing the hypothesis that the transition from La Niña to El Niño in 2008-2009 affected the “normal” periods in which ripe broodstock are collected and larvae are reared in a hatchery. Seasonal sampling included 2 reproductive periods (February and April 2009), 1 pre-reproductive period (November 2008), and 1 post-reproductive period (June 2009). Of the 40 oysters collected in each period, 20 were used for induced spawning and larval culture, while 20 were used to evaluate indices of reproductive performance. Water temperature, salinity, and seston content were monitored in each period. Sea surface temperature (SST) data associated with anomalous environmental conditions were obtained from the Aqua-MODIS satellite. Variations in SST affected reproductive performance more than larval performance in Pteria sterna. Spawning induction failed in November 2008 and succeeded in February, April, and June 2009, although only the larvae from April completed metamorphosis and settled, given the riper broodstock, larger oocytes, and favorable environmental conditions (21.80 °C; 31 mg·L-1 total seston; +0.50 °C SST). Positive SST anomalies (+0.50 to +1.10 °C) from August to December 2008 resulted in longer summer conditions that affected spawning in February 2009. In June 2009 (22.50 °C; 29.50 mg·L-1 total seston; +0.40 °C SST), when the percentages of ripe gonads and mature oocytes were small, the larvae were not viable, and few spat settled. In addition to collecting ripe broodstock in winter-spring for optimal larval and spat viability, we recommend including a brief conditioning period at the hatchery following the spawning peak and a second conditioning period in late autumn to promote nutrient recycling and natural gamete recovery.

Resumen. Se estudió el desempeño reproductivo y larvario de Pteria sterna en relación a factores ambientales anómalos, hipotetizando que la transición entre los eventos de La Niña y El Niño 2008-2009 afectó los periodos “normales” para recolectar reproductores maduros y cultivar larvas en laboratorio. Se realizaron muestreos estacionales en 2 periodos reproductivos (febrero y abril 2009), 1 periodo pre-reproductivo (noviembre 2008) y 1 periodo post-reproductivo (junio 2009). De las 40 ostras recolectadas en cada periodo, 20 se utilizaron para evaluar el desove y cultivo larvario y 20 para determinar indicadores de condición reproductiva. La temperatura, salinidad y contenido de seston se monitorearon en cada periodo. Los datos de temperatura superficial del mar (TSM) asociados a condiciones ambientales anómalas se obtuvieron del satélite Aqua-MODIS. Las variaciones en la TSM afectaron más el desempeño reproductivo que el desempeño larvario de Pteria sterna. La inducción al desove falló en noviembre 2008 y fue exitosa en febrero, abril y junio 2009, aunque solo en abril las larvas completaron la metamorfosis y se fijaron, a partir de reproductores más maduros, ovocitos más grandes y condiciones ambientales favorables (21.80 °C; ~31 mg·L-1 seston total; +0.50 °C TSM). Las anomalías positivas de TSM (+0.50 a +1.10 °C) de agosto a diciembre 2008 favorecieron un verano más largo que afectó el desove de febrero 2009. En junio 2009 (22.50 °C, 29.50 mg·L-1 seston total, +0.40 °C TSM), cuando los porcentajes de gónadas y ovocitos maduros eran bajos, las larvas no fueron viables y pocas semillas se fijaron. Además de recolectar reproductores maduros en invierno-primavera para una viabilidad óptima de las larvas y semillas, recomendamos incluir un breve periodo de acondicionamiento en el laboratorio después del pico de desove y un segundo a finales del otoño para promover el reciclaje de nutrientes y la recuperación natural de gametos.

Resumen Introducción: La Pácora (Plagioscion magdalenae) es una especie nativa de Colombia y en categoría de casi amenazada a nivel del país, de la que poco se conoce acerca de las estructuras con aporte etológico en su historia de vida. Objetivo: Analizar el desarrollo gonadal relacionado con la espermatogénesis de P. magdalenae y las implicaciones taxonómicas a partir de la vejiga natatoria. Métodos: Realizamos siete muestreos en dos periodos climáticos: el primero en octubre de 2019 a febrero de 2020 de recolectas bimensuales y la segunda de octubre 2020 a enero 2021 de recolectas mensuales; con el fin de abarcar cada momento del pulso de inundación de la cuenca baja del Magdalena. Describimos la histomorfología testicular y las características macroscópicas de la vejiga natatoria de la especie. Además, analizamos aspectos como relaciones morfométricas, clases de tallas por sexos, la proporción sexual y la época de madurez sexual. Resultados: Analizamos 142 ejemplares y 4 intervalos de tallas fueron establecidos (entre 145 y 575 mm LE), 66 fueron machos y 73 hembras con una proporción sexual global 1.1:0.9 (hembra-macho) sin diferencias. Los machos tienen testículos de tipo tubular, protegidos por el peritoneo que se encuentra recubierto por la musculatura sónica de la vejiga natatoria, la cual posee forma de ''zanahoria'' sin apéndices, con dos bandas laterales de músculos intrínsecos (promedio entre 6.75 cm de largo y 1.48 cm de ancho) unidos por una aponeurosis y que solo se encuentran en machos sexualmente maduros. Conclusión: Los testículos poseen una organización de tipo lobular irrestricto y la espermatogénesis se da en lóbulos seminíferos. La vejiga natatoria de la Pácora es simple y no tiene estructuras accesorias. La distribución geográfica de P. magdalenae se restringe a la cuenca del río Magdalena en Colombia.

Abstract Introduction: The Pácora (Plagioscion magdalenae) is a species native to Colombia and in near-threatened category at the country level, of which little is known about the structures with ethological contribution in its life history. Objective: To analyze the gonadal development related to spermatogenesis of P. magdalenae and the taxonomic implications from the swim bladder. Methods: We collected seven samples in two climatic periods: the first from October 2019 to February 2020 of bimonthly collections, and the second from October 2020 to January 2021 of monthly collections; to cover every moment of the flood pulse of the lower Magdalena basin. We described the testicular histomorphology and macroscopic characteristics of the swim bladder of the species. In addition, we analyzed aspects such as morphometric relationships, size classes by sex, sex ratio and time of sexual maturity. Results: We analyzed 142 specimens and established 4 size intervals (between 145 and 575 mm SL), 66 were males and 73 females with an overall sex ratio of 1.1:0.9 (female-male) with no differences. Males have tubular testes protected by the peritoneum covered by the sonic musculature of the swim bladder, which has a ''carrot'' shape without appendages, with two lateral bands of intrinsic muscles (average between 6.75 cm long and 1.48 cm wide) connected by an aponeurosis and found only in sexually mature males. Conclusion: The testes have an unrestricted lobular organization and spermatogenesis occurs in the seminiferous lobes. The swim bladder of the Pácora is simple and has no accessory structures. The geographic distribution of P. magdalenae is restricted to the Magdalena River basin in Colombia.

Abstract Environments contaminated with metals can induce accumulation of trace metals in soft tissues of marine fauna resulting in negative effects. The oral brooding sea star Anasterias minuta is one of the most con spicuous macro-invertebrate top-predator species in the Atlantic Patagonian rocky shores that could accumulate trace elements and be used as biomonitor of coastal metal pollution. The aim of this study was to quantify metals concentrations on gonads of A. minuta populations in an anthropogenic impacted and in a natural protected area. Sea stars A. minuta were collected from two rocky intertidal populations in San Matías Gulf, near an iron-ore loading wharf at Punta Colorada (PC), and in the Natural Protected Area Puerto Lobos (PL), located 35 km south to PC. The essential metals Fe, Mn, Zn, Cu, Cr and Ni, and the non-essential metal Cd and As were present in gonads of A. minuta from both populations. However, the essential metal Co and the non-essential metal Pb were only detected in the Natural Protected Area PL, with values below to quantification limit at PC. As high metal concentrations can impact negatively on sea star populations and shore habitats, this metal survey obtained from gonads of A. minuta populations could be useful as a reference to start a monitoring program in urbanized and marine protected areas.

Resumen Los ambientes contaminados con metales pueden inducir a la acumu lación de metales trazas en los tejidos blandos de la fauna marina, resultando en efectos negativos. La estrella de mar incubadora Anasterias minuta es una de las especies de depredadores superiores de macroinvertebrados más conspicuas en las costas rocosas de la Patagonia Atlántica que podría acumular elementos traza y usarse como biomonitor de la contaminación costera por metales. El objetivo de este estudio exploratorio fue cuantificar las concentraciones de metales en las gónadas de poblaciones de A. minuta en un área con impacto antrópico y en un Área Natural Protegida. Las estrellas de mar A. minuta fueron recolectadas de dos poblaciones intermareales rocosas del Golfo San Matías, cerca de un muelle de carga de mineral de hierro en Punta Colorada (PC), y en el Área Natural Protegida Puerto Lobos (PL), ubicada 35 km al sur de PC. Los metales esenciales Fe, Mn, Zn, Cu, Cr y Ni, y los metales no esenciales Cd y As estuvieron presentes en las gónadas de ambas poblaciones de A. minuta. Sin embargo, el metal esencial Co y el metal no esencial Pb fueron solo detectados en el Área Natural Protegida PL, con valores inferiores al límite de cuantificación en PC. Dado que las altas concentraciones de metales pueden tener un impacto negativo en las poblaciones de estrellas de mar y los hábitats costeros, estos datos de metales obtenidos de las gónadas de las poblaciones de A. minuta podrían ser útiles como referencia para comenzar un programa de monitoreo en áreas urbanizadas y marinas protegidas.

Abstract Triatoma melanocephala is an endemic species of Brazil. Phenotypic (external morphology) and molecular studies were performed to contribute to the taxonomy and phylogeny of triatomines, since few studies on the internal morphology of these were found. In order to contribute to the biological, morphological and taxonomic knowledge of the subfamily Triatominae, this work describes the internal morphology of the reproductive apparatus of adult males and females of T. melanocephala. For this work 30 specimens from Jequié, Bahia, Brazil were used. Triatoma melanocephala's reproductive system included slim spermathecae insertions, large/medium rounded terminal bodies, and irregular ellipsoid-shaped testicles with a transparent, vitreous appearance. These results contribute to the knowledge of the reproductive biology of this species of vectorial importance and show taxonomic relevance, as well as possible application in systematic studies.

Resumen Triatoma melanocephala es una especie endémica de Brasil. Se realizaron estudios fenotípicos (morfología externa) y moleculares para contribuir a la taxonomía y filogenia de los triatominos, ya que se encontraron pocos estudios sobre la morfología interna de estos. Con el fin de contribuir al conocimiento biológico, morfológico y taxonómico de la subfamilia Triatominae, este trabajo muestra la morfología interna del aparato reproductor de adultos machos y hembras de T. melanocephala. Para este trabajo se utilizaron 30 especímenes recolectados en Jequié, Bahía, Brasil. El sistema reproductivo de T. melanocephala incluye inserciones delgadas de espermatecas, cuerpos grandes/medianos con terminaciones redondeadas, y testículos de forma elipsoidal irregular con una apariencia transparente y vitrea. Estos resultados contribuyen al conocimiento de la biología reproductiva de esta especie de importancia vectorial y muestran relevancia taxonómica, así como su posible aplicación en estudios sistemáticos.

Abstract Long-term trends of length and mean age at sexual maturity (MLSM and MASM) of female Patagonian hoki Macruronus magellanicus (2001 to 2019) and southern hake Merluccius australis (1989 to 2019) were analyzed in overexploited stocks from the Outer Sea (OS) and Inner Sea (IS) of Chilean Patagonia. The study of the samples was performed by microscopic analysis of the gonads and part of them were analyzed histologically, together with fish otoliths readings. MLSM and MASM were calculated using a generalized linear model. MLSM of hoki in the OS experienced large annual fluctuations, with a difference of 16.2 cm between extreme values. MLSM was 55.3 cm in 2001 and 44.1 cm in 2019. MASM ranged between 2.9 and 4.4 years. In the IS (only one year sampled) precocious maturation was found in females between 32 cm and 35 cm total length (TL). MLSM of southern hake was rather stable within a range of 5.5 cm, from 73.5 cm TL in 1989 to 73.9 cm in 2019. MASM ranged between 10.4 and 11.6 years. MLSM in the IS was 4.5 cm TL lower than in the OS in the three years of sampling. Life history information of these species suggests that favorable environmental conditions in the IS allow them to reach MLSM earlier than in the OS.

Resumen Se analizó la tendencia a largo plazo de la longitud y edad media de madurez sexual (MLSM y MASM) de hembras de merluza de cola Macruronus magellanicus (2001 a 2019) y de merluza del sur Merluccius australis (1989 a 2019), en stocks sobrexplotados del Mar Exterior (OS) y Mar Interior (IS) de la Patagonia chilena. El estudio de las muestras se realizó mediante el análisis microscópico de las gónadas y parte de ellas se examinó histológicamente, junto con la lectura de otolitos. La MLSM y MASM se calcularon con un modelo lineal generalizado. La MLSM de la merluza de cola en el OS experimentó grandes fluctuaciones interanuales, con una diferencia de 16,2 cm entre los valores extremos, desde 55,3 cm longitud total (TL) en 2001 hasta 44,1 cm en 2019. El rango de la MASM fue entre 2,9 y 4,4 años. En el único año muestreado en el IS, se determinó maduración precoz en merluza de cola entre 32 y 35 cm TL. La MLSM en la merluza del sur mostró estabilidad dentro de un rango 5,1 cm, desde 73,5 cm TL en 1989 hasta 73,9 cm en 2019. La MASM presentó un rango desde 10,4 a 11,6 años. En los tres años muestreados en el IS, la MLSM fue menor en 4,5 cm TL al comparar con el OS. La información disponible sobre la historia de vida de estas especies sugiere que las favorables condiciones ambientales en el IS les permitirían alcanzar más tempranamente la MLSM que en el OS.

ABSTRACT The contamination of aquatic environments by microplastic has become a major threat to biodiversity. The presence of microplastic is documented in the aquatic fauna of the oceans, but, in the Amazon basin, reports on microplastic occurrence are few. The present study surveyed microplastic occurrence in fishes in an area of the Peruvian Amazon. We sampled 61 specimens of 15 commercial species from local markets in the city of Iquitos, Loreto Department. We detected a total of 2337 microplastic particles, 1096 in the gills and 1241 in the internal organs (esophagus, stomach, intestine, liver, gonads, pancreas, swim bladder and heart). The prevalence of microplastic particles was 100% and the overall average abundance was of 38.3 particles per individual (17.9 particles per individual in gills and 20.3 particles per individual in internal organs). Most particles were found in carnivorous fish. There was no correlation of particle abundance with fish standard length and weight. These results provided evidence of the degree of microplastic contamination of the fish fauna in the region of Iquitos. biodiversity oceans but basin few 6 1 Iquitos Department 233 109 124 esophagus, esophagus (esophagus stomach intestine liver gonads pancreas heart. heart . heart) 100 383 38 3 38. 17.9 179 17 9 (17. 203 20 20. organs. organs) weight 23 10 12 17. (17 2 (1 (

RESUMEN La contaminación de ambientes acuáticos por microplásticos se ha convertido en una gran amenaza para la biodiversidad. La presencia de microplásticos está bien documentada en la fauna acuática de los océanos, pero en la cuenca del Amazonas hay pocos reportes de ocurrencia. En este trabajo se investigó la ocurrencia de partículas de microplásticos en peces de un área de la Amazonía peruana. Se obtuvieron 61 especímenes de 15 especies comerciales provenientes de los mercados locales de la ciudad de Iquitos. Se detectó un total de 2337 partículas de microplástico, 1096 en las branquias y 1241 en los órganos internos (esófago, estomago, intestinos, hígado, gónadas, páncreas, vejiga natatoria y corazón). La prevalencia de partículas de microplástico fue del 100% y la abundancia general de partículas de microplástico fue de 38.3 partículas por individuo (17.9 partículas por individuo en las branquias y 20.3 partículas por individuo en los órganos internos). La mayor cantidad de particulas fué encontrada en peces carnivoros. No hubo correlación entre la abundancia de las particulas y el tamaño estandar y peso de los peces. Estos resultados proporcionan evidencia de los niveles de contaminación por microplásticos en la fauna de peces amazónica en la región de Iquitos. biodiversidad océanos peruana 6 1 Iquitos 233 109 124 esófago, esófago (esófago estomago intestinos hígado gónadas páncreas corazón. corazón . corazón) 100 383 38 3 38. 17.9 179 17 9 (17. 203 20 20. internos. internos) carnivoros 23 10 12 17. (17 2 (1 (

Abstract The sexual maturity of Oreochromis aureus was investigated and the elaboration of a protocol for use in rural aquaculture in the La Balsa Module in San Ignacio, Cajamarca-Peru. The evaluation of the sexual maturity of the tilapias was carried out in March and April 2022, considering the external and internal phenotypic characteristics of the gonads, the presence of eggs and larvae by mouthbrooding of the breeders, the IGS and the phases of sexual maturity. The maturity protocol was developed with the sexual characteristics and sequence of activities to be used in rural aquaculture. Differences were obtained in terms of males and females in color, shape and sex. In the stock of tilapia available in La Balsa, sizes of 21-30 cm and weights of 222-435 g were for males and 22,5-34,0 cm with weights of 250-674 g in females considered as spawners. partial from 1,0 to 2,5 years. It is concluded that the IGS fluctuated between 0,09 and 3,52% with a predominance of phase IV of sexual maturity, which was 43,75% in March and 62,5% in April.

Resumen Se investigó la madurez sexual de Oreochromis aureus y la elaboración de un protocolo para uso en la Acuicultura rural en el Módulo La Balsa en San Ignacio, Cajamarca-Perú. La evaluación de la madurez sexual de las tilapias se realizó en marzo y abril 2022, considerando las características fenotípicas externas e internas de las gónadas, la presencia de huevos y larvas por incubación bucal de las reproductoras, el IGS y las fases de madurez sexual. El protocolo de madurez se elaboró con las características sexuales y secuencia de actividades para ser usado en la Acuicultura rural. Se obtuvo diferencias en cuanto a machos y hembras en color, forma y sexo. En el stock de tilapias disponibles en La Balsa, las tallas de 21-30 cm y pesos de 222- 435 g fueron para los machos y de 22,5-34,0 cm con pesos 250-674 g en las hembras considerados como reproductores parciales de 1,0 a 2,5 años. Se concluye que el IGS fluctuó entre 0,09 y 3,52 % con predominancia de la fase IV de madurez sexual en marzo fue de 43,75 % y en abril del 62,5 %.

Resumo O conhecimento da morfologia testicular e ovariana de uma determinada espécie de peixe é de suma importância, pois através destas análises é possível o desenvolvimento de estudos e técnicas visando o melhoramento de sua reprodução, manejo e comercialização e até mesmo auxiliar em sua conservação. Este estudo realizou a caracterização ovariana e testicular do peixe Amazônico ornamental Serrapinnus kriegi. Um total de três machos e três fêmeas tiveram suas gônadas analisadas através de microscopia óptica. As fêmeas apresentam ovários preenchidos por oócitos em desenvolvimento assincrônico, indicando desova parcelada da espécie. Além disso, observou-se a formação de micrópila e célula micropilar em oócitos em crescimento primário, representando o desenvolvimento precoce do oócito; a zona radiata nos oócitos vitelogênicos finais é mais espessa em comparação a outras espécies relacionadas, evidenciando o desenvolvimento de uma melhor proteção aos embriões, em função das águas turbulentas que caracterizam seu local de desova nos córregos amazônicos. Os machos apresentam testículos do tipo tubular anastomosado com espermatogônias irrestritas, espalhadas por todo o túbulo seminífero. Os dados apresentados elucidam a dinâmica da espermatogênese e oogênese de uma espécie de peixe ornamental amazônica, por meio da descrição das células germinativas masculinas e femininas.

Abstract The knowledge of the testicular and ovarian morphology of a particular fish species is of paramount importance. Such analyze enables the development of studies and techniques aiming the improvement of their reproduction, management, commercialization and even their conservation. This study performed the ovarian and testicular characterization of the ornamental Amazon fish Serrapinnus kriegi. A total of three males and three females had their gonads analyzed by optical microscopy. Females present ovaries filled with oocytes in asynchronous development, indicating partial spawning in the species. Moreover, the micropyle and micropilar cell formation was observed in primary growing oocytes, representing a precocious oocyte development; and the zona radiata in the final vitellogenic oocytes is thicker than other related species, evidencing the development of a better protection to the embryos in function of the waters’ turbulence that characterize it spawning sites in the Amazonian streams. The male specimens’ present anastomosed tubular testes with unrestricted spermatogonia spread along the entire seminiferous tubules. The present data elucidate the dynamic of spermatogenesis and oogenesis of an ornamental Amazonian species, through the description of the male and female germ cells development.

Abstract The females of yellowtail tetra (Astyanax lacustris), known as the freshwater sardine, are approximately 1.33 times larger than males, and thus, all-female monosex culture would increase production and reduce size variability. The present work aimed to identify the optimal dose of 17α-methyltestosterone (MT) to be used in the masculinization of A. lacustris for indirect sex reversal. Three different concentrations of MT (20, 40, and 60 mg/kg of feed in the diet) were fed to the fry for 30 days. Thirty adult individuals from each treatment, including the control (0 mg MT/kg), were evaluated for gonadal development, morphological and histological sexual identification, zootechnical performance, and the possible genotoxic effect caused by prolonged exposure to MT. MT significantly (P<0.01) affected the differentiation of the gonads, with the presence of possible inhibitory effects in all treatments. Intersex individuals were present in the 20 and 60 mg MT/kg treatments. All treatments were able to masculinize A. lacustris and the treatment with the lowest hormone concentration produced the highest percentage of males 76.7%, while the control had 46.7% males. The presence of erythrocyte nuclear alterations indicated a possible cytotoxic effect of MT in treatments 40 and 60 mg MT/kg, however, the use of the hormone did not affect the growth and the survival of the individuals. Thus, the use of MT is a viable option for obtaining neomales as a first step into the production of all-female progenies. Astyanax lacustris, , lacustris) sardine 133 1 33 1.3 thus allfemale female variability 17αmethyltestosterone αmethyltestosterone 17α methyltestosterone α (MT A reversal 20, (20 6 mgkg kg diet 3 days 0 ( MTkg MT/kg) development identification performance P<0.01 P001 P 01 (P<0.01 gonads 2 767 76 7 76.7% 467 46 46.7 4 however Thus progenies 13 1. (2 P<0.0 P00 (P<0.0 76.7 46. P<0. P0 (P<0. 76. P<0 (P<0 P< (P< (P