Resumen. Los tambores y roncadores (Sciaenidae) son parte importante de la composición específica de las capturas costeras en el Golfo de California, México. Dentro de este grupo de especies, la curvina rayada (Cynoscion reticulatus) destaca por su alto potencial pesquero, gran demanda y debido a que ha incrementado su valor de mercado. La curvina rayada ha estado bajo constante presión pesquera durante los últimos 20 años. Sin embargo, se necesita contar con información biológica actual o puntos de referencia que permitan establecer medidas de manejo pesquero. Por tanto, el objetivo del presente estudio fue estimar la longitud estándar media de madurez sexual (LE 50 ) utilizando varios modelos para sugerir una talla mínima de captura (TMC) de C. reticulatus en la costa sur de Sinaloa. Para esto, se realizaron muestreos mensuales en las descargas de la flota costera desde diciembre de 2020 hasta diciembre de 2021 en la costa sur de Sinaloa. La LE 50 se evaluó con base en 3 modelos candidatos (Gompertz, Lysack y White) a través de un enfoque binomial. Los intervalos de confianza para la LE 50 se estimaron utilizando perfiles y contornos de verosimilitud, y se utilizó el criterio de información de Akaike (CIA) para seleccionar el mejor modelo. Se examinaron un total de 284 individuos, de los cuales 131 se utilizaron en el análisis. El modelo de White fue el más adecuado; sin embargo, con base en los pesos de CIA, los 3 modelos mostraron un rendimiento similar, por lo que la LE50 (24.48 cm; IC 95% 12.9-36.0 cm) se estimó como el promedio de estos. Por último, como medida de manejo, proponemos una TMC bajo un enfoque precautorio de 36 cm LE para C. reticulatus en la costa sur de Sinaloa.

Abstract. Drums and croakers (Sciaenidae) are important to the species composition of coastal catches in the Gulf of California, Mexico. Among these species, the striped corvina (Cynoscion reticulatus) stands out because of its high fishery potential, high demand, and increased market value. The striped croaker has been under constant fishing pressure over the past 20 years. Still, there needs to be current biological information or reference points to allow the establishment of management measures for fisheries. The objective of the present study was to estimate the mean standard length at sexual maturity (SL 50 ) of females using various models and to suggest a minimum catch size (MCS) for C. reticulatus off the southern coast of Sinaloa. Monthly samplings of coastal fishery landings were done from December 2020 to December 2021 on the south coast of Sinaloa. The SL 50 was evaluated based on 3 candidate models (Gompertz, Lysack, and White) through a binomial approach. Confidence intervals for SL 50 were estimated using likelihood profiles and contours, and Akaike’s information criterion (AIC) was used to select the best model. A total of 284 individuals were examined, of which 131 were used in calculations. White’s model was the most adequate; however, based on AIC weights, all 3 models performed similarly, and SL 50 (24.48 cm; C.I. 95% 12.9-70 36.0 cm) was estimated as their average. As a management measure, we propose a precautionary MCS of 36 cm SL for C. reticulatus off southern Sinaloa.

SUMMARY: The study was designed to explore the association between the immunolocalization of alpha-smooth muscle actin (α- SMA) and S100 proteins within the efferent ductules (ED) from one side, and the sexual maturity and seasonality from the other side. For each season, tissue specimens were obtained from 7 adult and 7 juvenile, clinically healthy male dromedaries. Specimens were investigated by the standard immunohistochemical procedures. The immunohistochemical findings displayed that the pattern of expression was similar for both proteins, either in adults or in juveniles. Expression was significantly higher in adults during season of sexual activity (winter), fairly reduced during periods of transition from activity to inactivity (spring) or from inactivity to activity (autumn) and reaches its lowest magnitude during season of sexual inactivity (summer). On the other hand, a moderate immunoreactivity of both proteins in ED from juvenile male camels was nearly uniform throughout the year. The immunoreactivity for both α-SMA (smooth muscle cells in ductular and vascular walls) and S100 (ductular ciliated cells), was evident during periods of sexual activity. It can be concluded that the immunoreactivity is androgen- dependent and positively correlated with both of sexual activity and maturity, suggesting a crucial role of both α-SMA and S100 proteins in the regulation of the diverse functions of the ED in male dromedaries.

RESUMEN: El estudio fue diseñado para explorar la asociación entre la inmunolocalización de la actina de músculo liso alfa (α-SMA) y las proteínas S100 dentro de los conductos eferentes (ED) por una pate, y la madurez sexual y estacionalidad por otra parte. Para cada estación, se obtuvieron muestras de tejido de 7 dromedarios machos adultos jóvenes y clínicamente sanos. Las muestras se investigaron mediante procedimientos inmunohistoquímicos estándar. Los hallazgos inmunohistoquímicos mostraron que el patrón de expresión era similar para ambas proteínas, ya sea en adultos o en jóvenes. La expresión fue significativamente mayor en adultos durante la temporada de actividad sexual (invierno), bastante reducida durante los períodos de transición de actividad a inactividad (primavera) o de inactividad a actividad (otoño) y alcanzaba su magnitud más baja durante la temporada de inactividad sexual (verano). Por otro lado, una inmunorreactividad moderada de ambas proteínas en el DE de camellos machos juveniles fue casi uniforme durante todo el año. La inmunorreactividad tanto para α-SMA (células musculares lisas en las paredes ductulares y vasculares) como para S100 (células ciliadas ductulares), fue evidenciada durante los períodos de actividad sexual. Se puede concluir que la inmunorreactividad es dependiente de los andrógenos y se correlaciona positivamente tanto con la actividad sexual como con la madurez, lo que sugiere un papel crucial de las proteínas α-SMA y S100 en la regulación de las diversas funciones del DE en dromedarios machos.

Abstract A total of 381 specimens of the tilapia Oreochromis mossambicus collected monthly from May 2017 to May 2018 in the Laguna de Los Patos, Cumaná, Venezuela, to evaluate reproductive parameters of this non-native species. Significant differences were found in relation to average height and weight between males and females, with the highest values in males. The sex ratio was 1:1.5 (males:females), which deviates significantly from the expected 1:1 ratio. The mean length of sexual maturity (Lm50) was 18.0 cm in females and 20.1 cm in males, reflecting that females mature at smaller sizes than males. The monthly variations of the gonadosomatic index (GSI) and the stages of sexual maturity show two reproductive peaks during the study, in October 2017 and April 2018, coinciding with the rainy and dry seasons in the region respectively. The condition factor (CF) showed significant differences between months, but not between sexes, with an average of 1.87 in females and 1.84 in males. The average absolute fecundity was 921 ± 604.6 eggs per fish, with a relative fecundity of 8.36 ± 3.09 eggs per gram of fish. Differences in oocyte size in mature females confirm that the species can spawn repeatedly over a period, which is considered an important factor for the establishment of tilapia in non-native environments. 38 201 Patos Cumaná Venezuela nonnative non native 11.5 115 1 1.5 5 1:1. malesfemales, malesfemales , (males:females) 11 1: Lm50 Lm (Lm50 180 18 0 18. 20 20. GSI (GSI study respectively CF (CF months sexes 187 87 1.8 184 84 92 6046 604 6 604. fish 836 8 36 8.3 309 3 09 3.0 period environments 11. 15 1. (males:females Lm5 (Lm5 2 9 60 83 8. 30 3. (Lm

Resumo Um total de 381 espécimes da tilápia Oreochromis mossambicus foram coletados mensalmente de maio de 2017 a maio de 2018, na Laguna de Los Patos, Cumaná, Venezuela, para avaliar parâmetros reprodutivos desta espécie não nativa. Foram encontradas diferenças significativas em relação às médias de altura e peso entre machos e fêmeas, sendo os maiores valores no sexo masculino. A razão sexual foi de 1:1,5 (machos:fêmeas), o que se desvia significativamente da proporção esperada de 1:1. O comprimento médio de maturação sexual (Lm50) foi de 18,0 cm nas fêmeas e 20,1 cm nos machos, refletindo que as fêmeas amadurecem em tamanhos menores que os machos. As variações mensais do índice gonadossomático (IGS) e dos estágios de maturidade sexual mostram dois picos reprodutivos durante o estudo, em outubro de 2017 e abril de 2018, coincidindo com as estações chuvosa e seca na região, respectivamente. O fator de condição (FC) apresentou diferenças significativas entre os meses, mas não entre os sexos, com média de 1,87 no sexo feminino e 1,84 no masculino. A fecundidade absoluta média foi de 921 ± 604,6 ovos por peixe, com fecundidade relativa de 8,36 ± 3,09 ovos por grama de peixe. Diferenças no tamanho dos ovócitos em fêmeas maduras confirmam que a espécie pode desovar repetidamente ao longo de um período, o que é considerado um fator importante para o estabelecimento de tilápias em ambientes não nativos. 38 201 2018 Patos Cumaná Venezuela nativa masculino 11,5 115 1 1,5 5 1:1, machosfêmeas, machosfêmeas , (machos:fêmeas) 11. 11 1. 1:1 Lm50 Lm (Lm50 180 18 0 18, 20 20, IGS (IGS estudo região respectivamente FC (FC meses sexos 187 87 1,8 184 84 92 6046 604 6 604, peixe 836 8 36 8,3 309 3 09 3,0 período nativos 11, 15 1, (machos:fêmeas 1: Lm5 (Lm5 2 9 60 83 8, 30 3, (Lm

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

Resumo O polvo com chifres Eledone cirrhosa, uma espécie de tamanho médio encontrada no Golfo Arábico ao largo da Arábia Saudita, foi coletado mensalmente no Golfo Arábico ao largo da cidade de Dammam durante o período de janeiro a dezembro de 2022. As amostras foram dissecadas e preparadas para exame por microscopia eletrônica. Durante a maturação genital, os túbulos seminíferos se estabelecem nos testículos, com espermatogônias ativas se dividindo. Espermatócitos 1 são observados no túbulo, seguidos de aumento de espermatogônias e espermatócitos em agosto. A espermiogênese começa com espermátides esféricas evoluindo para espermátides alongadas. Em setembro, as espermatogônias ativas, as divisões meióticas e o aumento da espermiogênese continuam. Os espermatozoides aparecem na Bolsa de Needham, indicando maturidade sexual. O ovário passa por vários estágios de desenvolvimento, com oócitos no estágio I em junho e julho, seguido pelo estágio II em outubro e novembro. No estágio IIIc, os cordões foliculares invadem o citoplasma do oócito, formando numerosas inclusões lipídicas e grânulos proteicos. O citoplasma contém cisternas de retículo endoplasmático e um Aparelho de Golgi pouco desenvolvido. O estágio IV ocorre em novembro, caracterizado pelo máximo desenvolvimento dos cordões foliculares e pelo início da vitelogênese. O ooplasma contém numerosas inclusões lipídicas, um sincício e células secretoras. A partir de dezembro, os oócitos do estágio V estão principalmente presentes, indicando a fase de atividade de secreção máxima. As plaquetas da gema acumulam-se no ooplasma do ovócito e o córion se forma na zona pelúcida. Em janeiro, os primeiros óvulos lisos são encontrados no ovário de alguns polvos e sua proporção aumenta continuamente. Este estudo teve como objetivo investigar a ação mitogênica da gonadotrofina bem como identificar os períodos de intensa multiplicação celular durante o ciclo sexual por meio de métodos citológicos. cirrhosa Saudita 2022 eletrônica genital testículos dividindo túbulo agosto alongadas setembro continuam Needham julho novembro IIIc oócito proteicos desenvolvido vitelogênese secretoras presentes máxima acumulamse acumulam pelúcida continuamente citológicos 202 20 2

Abstract The horned octopod Eledone cirrhosa, a medium-sized species found in Arabian Gulf off Saudi Arabia, was collected monthly from the Arabian Gulf off Dammam city during January to December 2022. Samples were dissected and prepared for examination using transmission electron microscopy. During genital maturation, seminiferous tubules are established in the testis, with active spermatogonia dividing. Spermatocytes 1 are observed in the tubule, followed by an increase in spermatogonia and spermatocytes in August. Spermiogenesis begins, with spherical spermatids evolving into elongated spermatids. In September, active spermatogonia, meiotic divisions, and increased spermiogenesis continue. Spermatozoa appear in Needham's pouch, indicating sexual maturity. The ovary undergoes various stages of development, with oocytes at stage I in June and July, followed by stage II in October and November. In stage III, follicular cords invade the oocyte's cytoplasm, forming numerous lipid inclusions and protein granules. The cytoplasm contains cisternae of endoplasmic reticulum and a poorly developed Golgi apparatus. Stage IV occurs in November, characterized by the maximum development of follicular cords and the beginning of vitellogenesis. The ooplasm contains numerous lipid inclusions, a syncytium, and secretory cells. From December, stage V oocytes are mainly present, indicating the activity phase of maximum secretion. Yolk platelets accumulate in the oocyte ooplasm, and chorion forms at the zona pellucida. In January, the first smooth eggs are found in some octopuses' ovary, with their proportion increasing steadily. This study aimed to investigate the mitogenic action of gonadotropin and identify the periods of intense cell multiplication during the sexual cycle using cytological methods. cirrhosa mediumsized medium sized Arabia 2022 microscopy maturation testis dividing tubule August begins September divisions continue Needhams Needham s pouch maturity July November III granules apparatus vitellogenesis syncytium cells present secretion pellucida octopuses steadily methods 202 20 2

Resumo O objetivo deste estudo foi estimar o tamanho na primeira maturidade sexual (Lm) para 36 espécies pertencentes a 24 famílias do hábitat marinho do Baluchistão e Sindh, no Mar Arábico, Paquistão, por meio de modelo empírico e logístico com base no comprimento máximo usando captura comercial, durante junho de 2020 e maio de 2021. O comprimento total individual (TL) foi anotado até 0,1 cm usando medição ampla. O Lm foi calculado por duas fórmulas; (i) log (Lm) = - 0,1246 + 0,9924 * log (Lmax) para elasmobrânquios; e (ii) log (Lm) = - 0,1189 + 0,9157* log (Lmax) para peixes com nadadeiras raiadas. O Lm mínimo foi de 10,27 cm de TL para Caranx malabaricus, e o máximo, de 108,38 cm de TL para Isurus oxyrinchus. Em 58,33% das espécies com Lm foram encontradas faixas de 19,00 cm a 25,00 cm de TL. Este estudo estimou que 16 espécies com Lm estão globalmente ausentes e as 20 espécies restantes com Lm estão ausentes no Mar Arábico (hábitats costeiros do Paquistão). Portanto, os resultados serão úteis para o manejo sustentável e a conservação desses peixes marinhos por meio do estabelecimento da malhagem das redes de arrasto com base no tamanho na primeira maturidade sexual (Lm).

Abstract The aim of this study was to estimate the size at first sexual maturity (Lm) for 36 species belonging to 24 families from the marine habitat of Balochistan and Sindh in Arabian Sea, Pakistan through maximum length based an empirical and logistic model using commercial catch during June 2020 to May 2021. Individual total length (TL) was noted up to 0.1 cm using measuring broad. The Lm was calculated using two formulae; (i) log (Lm) = - 0.1246 + 0.9924 * log (Lmax) for Elasmobranchs and (ii) log (Lm) = -0.1189 + 0.9157* log (Lmax) for ray-finned fishes. The minimum Lm was recorded as 10.27 cm TL for Caranx malabaricus and 108.38 cm TL for Isurus oxyrinchus, respectively. Around Lm with 58.33% species were ranges from 19.00 cm to 25.00 cm TL. This study was estimated 16 newly Lm which is globally absent and rest 20 Lm are absent in the Arabian Sea (Pakistan coastal habitats). Therefore, the results will be helpful for the sustainable management and conservation of these marine fishes through the establishment of mesh size of trawl nets based on the size at sexual maturity (Lm).

ABSTRACT: When applied at growing phase, lighting program aims to obtain quails with body weight and physiological maturity suitable for the beginning of laying. This study evaluated lighting programs at growing phase on performance, sexual maturity and egg quality of meat quail breeders (Coturnixcoturnix) at laying phase. From 7 to 49 days of age, 300 female meat quails were subjected to three lighting programs (natural, intermittent and continuous), with 5 replicates of 20 birds each. At 49 days of age, 240 quails were transferred to a shed, maintaining the same experimental conditions. Meat quails submitted to continuous and intermittent lighting programs had higher weight of reproductive system and lower ages for first egg production and to reach 50% of egg production (P < 0.05). Quails submitted to natural lighting had lower feed intake from 49 to 70 and 71 to 92 days of age and worse feed conversion up to 114 days of age. Continuous and intermittent lighting programs resulted in more precocious quails compared to natural lighting program. Quails submitted to natural lighting at growing phase presented lower egg production during all periods, not differing for birds submitted to continuous and intermittent programs from the second period (71 to 92 days of age). Intermittent and continuous lighting result in better feed conversion of breeding quails up to 114 days and a higher percentage of laying (49 to 136 days), reducing the number of days to produce the first egg and to reach 50% of laying, in relation to natural lighting. ABSTRACT performance Coturnixcoturnix (Coturnixcoturnix 4 30 natural, (natural continuous, , continuous) 2 each 24 shed conditions 50 P 0.05. 005 0.05 . 0 05 0.05) 9 11 periods (7 age) (4 13 days, days) 3 00 0.0 1 ( 0.

RESUMO: Quando aplicado na fase de crescimento, o programa de luz visa obter codornas com peso corporal e maturidade fisiológica adequados para o início da postura. Este estudo avaliou programas de iluminação na fase de crescimento sobre o desempenho, maturidade sexual e qualidade dos ovos de codornas de corte reprodutoras (Coturnix coturnix) na fase de postura. Durante o período de sete a 49 dias de idade, 300 codornas de corte fêmeas foram submetidas a três programas de iluminação (natural, intermitente e contínuo), com cinco repetições de 20 aves cada. Aos 49 dias de idade, 240 codornas foram transferidas para um galpão, mantendo a mesma distribuição experimental e submetidas às mesmas condições. As aves submetidas aos programas de iluminação contínuo e intermitente na fase de crescimento apresentaram maiores peso relativo do sistema reprodutivo e consequentemente menores idades para produção do primeiro ovo e para atingir 50% da produção de ovos (P < 0.05). As aves que receberam apenas iluminação natural apresentaram menor consumo de ração nos períodos de 49 a 70 e 71 a 92 dias de idade e pior conversão alimentar até 114 dias de idade. Os programas de iluminação contínua e intermitente na fase de crescimento resultaram em codornas mais precoces quando comparados as aves submetidas ao programa de iluminação natural. Codornas submetidas a programa de luz natural na fase de crescimento apresentaram menor produção de ovos durante todos os períodos, não diferindo das aves submetidas a programas contínuos e intermitentes a partir do segundo período (71 a 92 dias de idade). A iluminação intermitente e contínua na fase de crescimento resulta em melhor conversão alimentar de codornas reprodutoras até 114 dias e maior percentual de postura (49 a 136 dias), reduzindo o número de dias para produzir o primeiro ovo e atingir 50% de postura, em relação a iluminação natural.. RESUMO desempenho Coturnix coturnix 4 30 natural, (natural contínuo, , contínuo) 2 cada 24 galpão condições 50 P 0.05. 005 0.05 . 0 05 0.05) 7 9 11 (7 idade) (4 13 dias, dias) 3 5 00 0.0 1 ( 0.

Abstract Daily rhythms of behavior and their synchronization in relevant social contexts are fundamental for the survival and reproductive success of all animal species. South American annual fish are adapted to extreme environmental conditions, where the ponds they inhabit dry out as the year progresses, while engaging in reproductive behavior from sexual maturity to death. The ever-changing environmental cycles these species are subjected to makes them an excellent model for studying the expression of biological rhythms in nature. In this work we show for the first time that Garcialebias reicherti, an annual fish native to Uruguay shows daily rhythms in both their locomotor and reproductive behavior. This species shows diurnal behavioral patterns, with neither sex nor reproductive context affecting the phase relationship between the light/dark cycle and activity. However, reproductive context modulates the amount of locomotor activity and leads to synchronization between members of the dyads, while introducing a second behavioral rhythm for reproductive events. Reproductive context emerges as a significant modulator of rhythmic behavior, driving circadian rhythms synchronization alongside environmental zeitgebers, while illuminating the complexity of physiological and behavioral coordination. conditions progresses death everchanging ever changing nature reicherti patterns lightdark light dark However dyads events zeitgebers coordination

Resumen Los ritmos diarios de la conducta y su sincronización en contextos sociales relevantes son fundamentales para la supervivencia y el éxito reproductivo. Los peces anuales sudamericanos están adaptados a condiciones ambientales extremas, donde los charcos que habitan se secan a medida que avanza el año, mientras despliegan conducta reproductiva desde la madurez sexual hasta su muerte. Los ciclos ambientales extremos a los que estas especies están expuestas las convierten en un modelo excelente para estudiar la expresión de los ritmos biológicos en la naturaleza. En este trabajo mostramos por primera vez que Garcialebias reicherti, un pez anual nativo de Uruguay, muestra ritmos diarios tanto en su comportamiento locomotor como reproductivo. Esta especie muestra patrones de comportamiento diurnos, sin que el sexo ni el contexto reproductivo afecten el enganche de fase entre el fotoperiodo y la conducta. Sin embargo, el contexto reproductivo modula la cantidad de actividad locomotora y promueve la sincronización entre los integrantes de las díadas, al tiempo que introduce el comportamiento reproductivo como otro ritmo conductual. El contexto social emerge como un modulador significativo de la conducta rítmica, funcionando en conjunto con los zitegebers ambientales, poniendo en evidencia una compleja coordinación fisiológica y conductual. extremas año muerte naturaleza reicherti Uruguay diurnos embargo díadas conductual rítmica

ABSTRACT The South Pacific hake, Merluccius gayi, is an ecologically and economically important species in Ecuador. However, studies regarding its feeding habits remain scarce. This study aimed to characterize the food and feeding habits of M. gayi in the Ecuadorian Pacific Ocean by sex, sexual maturity stages, size classes, and years. Hakes obtained (n = 2993) from industrial fishing (captured with seine nets) were analyzed from September 2013 to December 2014. Their diet was composed of 27 prey species. The most important prey was the euphausiid Nyctiphanes simplex (52%) and the same hake species (M. gayi; 31%) according to the prey-specific index of relative importance (%PSIRI), making this species a cannibal predator. Results show no significant dietary differences between female and male hakes or immature and mature males, but found differences between immature and mature females and individuals from four size classes and hake between 2013 and 2014. According to Levin’s Index, the species showed a low trophic niche breadth (Bi = 0.03), making it a selective specialist mesopredator with high specialization. The trophic overlap analysis based on Jaccard’s index by sex was low (J = 0.23) for indetermined individuals, moderate (J = 0.59) for males and females, and high (J = 0.78) for immature females and males; moderate values were noted for size classes (J = 0.42-0.63) and low for years (J = 0.31). Based on the Cortés index, the trophic level totaled (TLk = 3.22), indicating that this species is a primary and secondary carnivore mesopredator. This information supports the understanding of the relations between predators and prey and the flow of nutrients and energy in marine ecosystems, which serve as a base for ecosystemic fishing management. Ecuador However scarce M stages n 2993 captured nets 201 2014 2 52% 52 (52% (M 31% 31 preyspecific specific %PSIRI, PSIRI %PSIRI , (%PSIRI) predator Levins Levin s Index Bi 0.03, 003 0.03 0 03 0.03) specialization Jaccards Jaccard J 0.23 023 23 0.59 059 59 0.78 078 78 0.420.63 042063 0.42 0.63 42 63 0.42-0.63 0.31. 031 0.31 . 0.31) TLk 3.22, 322 3.22 3 22 3.22) ecosystems management 299 20 5 (52 (%PSIRI 00 0.0 0.2 02 0.5 05 0.7 07 7 420 0.420.6 04206 042 0.4 063 0.6 4 6 0.42-0.6 0.3 32 3.2 29 (5 0. 0.420. 0420 04 06 0.42-0. 3. ( 0.420 0.42-0 0.42-

Abstract This review elucidates the physiological and endocrinological processes intrinsic to puberty and ovulation induction protocols in Bos indicus and Bos taurus beef heifers. Puberty is a complex physiological event involving gonadotropic and metabolic changes that lead to sexual maturity, first ovulation, and regular reproductive cycles, enabling females to reproduce. Exposure to progesterone-based hormonal protocols, with or without additional hormones, can reduce the age at first ovulation and improve sexual maturity through stimuli in the hypothalamus-pituitary-gonadal (HPG) axis and uterine development. However, inducing puberty differs from inducing ovulation, as it does not ensure the heifer will continue cycling or be ready to establish and maintain pregnancy after hormonal exposure. Regardless of the pharmacological basis, studies consistently report that beef heifers that had a corpus luteum (CL) prior to the timed-artificial insemination (TAI) protocol, have greater expression of estrus in response to synchronization and greater pregnancy per AI compared to heifers without a CL. The combination of P4 and E2 significantly impacts uterine development, increasing reproductive efficiency. Exposure to P4 causes a positive effect on inducing ovulation. However, studies indicate that the addition of E2 esters at the time of P4 device removal increases the ovulation rate. In general, the studies showed that fertility varied according to the type of the ovulation induction protocol used, but with inconsistent results. Although ovulation induction protocols are strategic tools to accelerate sexual maturity, a holistic view of the entire system is extremely important, combining integration with genetics and nutrition to enhance the reproductive outcomes of beef heifers. Future research is needed to understand and refine these protocols, driving the efficiency of beef cattle production systems. cycles reproduce progesteronebased progesterone based hormones hypothalamuspituitarygonadal hypothalamus pituitary gonadal HPG (HPG development However exposure basis CL (CL timedartificial timed artificial TAI (TAI P E rate general used results important systems

Abstract Assisted reproductive technologies (ART) are fundamental for cattle breeding and sustainable food production. Together with genomic selection, these technologies contribute to reducing the generation interval and accelerating genetic progress. In this paper, we discuss advancements in technologies used in the fertility evaluation of breeding animals, and the collection, processing, and preservation of the gametes. It is of utmost importance for the breeding industry to select dams and sires of the next generation as young as possible, as is the efficient and timely collection of gametes. There is a need for reliable and easily applicable methods to evaluate sexual maturity and fertility. Although gametes processing and preservation have been improved in recent decades, challenges are still encountered. The targeted use of sexed semen and beef semen has obliterated the production of surplus replacement heifers and bull calves from dairy breeds, markedly improving animal welfare and ethical considerations in production practices. Parallel with new technologies, many well-established technologies remain relevant, although with evolving applications. In vitro production (IVP) has become the predominant method of embryo production. Although fundamental improvements in IVP procedures have been established, the quality of IVP embryos remains inferior to their in vivo counterparts. Improvements to facilitate oocyte maturation and development of new culture systems, e.g. microfluidics, are presented in this paper. New non-invasive and objective tools are needed to select embryos for transfer. Cryopreservation of semen and embryos plays a pivotal role in the distribution of genetics, and we discuss the challenges and opportunities in this field. Finally, machine learning (ML) is gaining ground in agriculture and ART. This paper delves into the utilization of emerging technologies in ART, along with the current status, key challenges, and future prospects of ML in both research and practical applications within ART. ART (ART selection progress animals possible decades encountered breeds practices wellestablished well established relevant (IVP counterparts systems eg e g e.g microfluidics noninvasive non invasive transfer genetics field Finally (ML status

ABSTRACT This study assessed the effect of strain and enriched cage stocking density on performance, egg size distribution, egg quality, and welfare status in laying hens. Lohmann brown (LB) and Lohmann LSL Classic (LW) strains at 20 weeks of age were allotted to different cage stocking densities, with 1016, 762, or 610 cm2 of cage floor area per hen. Live body weight at the age at sexual maturity and at 52 weeks of age, feather condition, and some egg quality parameters differed between hen strains and among stocking densities (p<0.01; p<0.05). However, age at sexual maturity, livability, egg production, heterophil-to-lymphocyte ratio, and duration of tonic immobility were similar between hen strains and among stocking densities (p>0.05). Furthermore, egg size distribution was similar between hen strains (p>0.05), but dissimilar among stocking densities (p<0.01). Rectal and comb temperatures differed between hen strains and among stocking densities, respectively (p<0.01; p<0.05). The age of hens influenced egg quality variables (except for egg weight and shape index), feather condition, and body region temperatures (p<0.01). These results suggest that an enriched cage floor area of up to 610 cm2 per hen does not compromise production performance and welfare status, except for the body weight of laying hens. Additionally, the two strains might be at similar levels regarding overall performance and welfare status, excluding body weight and feather condition. LB (LB LW (LW 2 1016 762 61 cm 5 condition p<0.01 p001 p 0 01 (p<0.01 p<0.05. p005 p<0.05 . 05 p<0.05) However livability heterophiltolymphocyte heterophil lymphocyte ratio p>0.05. p>0.05 (p>0.05) Furthermore p>0.05, , p<0.01. (p<0.01) index, index index) Additionally 101 76 6 p<0.0 p00 (p<0.0 p>0.0 (p>0.05 10 7 p<0. p0 (p<0. p>0. (p>0.0 1 p<0 (p<0 p>0 (p>0. p< (p< p> (p>0 (p (p>

Abstract The study of reproductive biology is an important tool in identifying protective measures to preserve fish stocks, providing essential data for a reliable management system that ensures a balance between the environment and the economy. This study aims to analyze the first sexual maturity and type of spawning of the fish Conodon nobilis (Linnaeus, 1758) on the Amazon coast, specifically in the Gulf Maranhense region. 360 specimens were obtained from commercial fishing activity in the community of Raposa-MA during the period from January to December 2021. Biometric data were recorded, and the gonadal maturation stages were determined through macro (maturation scale) and microscopic (histology) analyzes. Sex ratio, mean length of first sexual maturation and type of spawning were determined. Negative allometric growth was recorded for both sexes, indicating a greater increase in length than in weight, and the length varied from 11 to 31.8 cm and the sex ratio was 1 male:1.5 female. Individuals in all stages of maturation were observed throughout the year, with a predominance of individuals in spawning capacity and reproductive peaks in January, April and May, indicating that the species presents multiple spawning. The length at first sexual maturity (L50) for females was 18.41 cm and for males was 18.91 cm. Knowledge of the mean size at sexual maturity can help define appropriate regulations for fishing, ensuring that individuals have the opportunity to reproduce at least once before being captured. stocks economy Linnaeus, Linnaeus (Linnaeus 1758 coast region 36 RaposaMA Raposa MA 2021 scale histology (histology analyzes sexes weight 318 31 8 31. male1.5 male15 male 1.5 5 male:1. female year May L50 L (L50 1841 18 41 18.4 1891 91 18.9 captured 175 3 202 male1 male1. 15 1. male:1 L5 (L5 184 4 18. 189 9 17 20 male: (L 2

Resumo O estudo da biologia reprodutiva é uma abordagem importante na identificação de medidas de proteção para preservar os estoques pesqueiros, fornecendo dados essenciais para um sistema de gestão confiável que garanta o equilíbrio entre o meio ambiente e a economia. Neste estudo objetivou-se analisar a primeira maturidade sexual e o tipo de desova do peixe Conodon nobilis (Linnaeus, 1758) na costa amazônica, especificamente na região do Golfão Maranhense. Foram obtidos 360 exemplares provenientes da atividade de pesca comercial na comunidade pesqueira de Raposa-MA durante o período de janeiro a dezembro de 2021. Foram registrados dados biométricos e determinados os estágios de maturação gonadal por meio de análises macroscópicas (escala de maturação) e microscópicas (histologia). Foram determinados a razão sexual, a duração média da primeira maturação sexual e o tipo de desova. Foi registrado crescimento alométrico negativo para ambos os sexos, indicando maior aumento no comprimento do que no peso, sendo que o comprimento variou de 11 a 31.8 cm e a proporção sexual foi de 1 macho:1.5 fêmea. Foram observados indivíduos em todos os estágios de maturação durante todo o ano, com predomínio de indivíduos em capacidade reprodutiva e picos reprodutivos em janeiro, abril e maio, indicando que a espécie apresenta desovas múltiplas. O comprimento na primeira maturidade sexual (L50) para as fêmeas foi de 18.41 cm e para os machos foi de 18.91 cm. O conhecimento do tamanho médio na maturidade sexual pode ajudar a definir regulamentos apropriados para a pesca, garantindo que os indivíduos tenham a oportunidade de se reproduzir pelo menos uma vez antes de serem capturados. pesqueiros economia objetivouse objetivou Linnaeus, Linnaeus (Linnaeus 1758 amazônica Maranhense 36 RaposaMA Raposa MA 2021 escala histologia. histologia . (histologia) sexos peso 318 31 8 31. macho1.5 macho15 macho 1.5 5 macho:1. fêmea ano maio múltiplas L50 L (L50 1841 18 41 18.4 1891 91 18.9 capturados 175 3 202 (histologia macho1 macho1. 15 1. macho:1 L5 (L5 184 4 18. 189 9 17 20 macho: (L 2