ABSTRACT. The order Ingolfiellida (Crustacea, Peracarida) represents a small group of peracarid crustaceans, usually less than 3 mm long and comprising 53 species in several ecosystems worldwide. Previously, eight ingolfiellid species had been documented from the Intra-Americans Sea: one from the Gulf of Mexico and eastern Florida and seven from the Caribbean Sea, including the Bahamas. A new deep-sea species of Ingolfiella is described based on material collected from bathyal soft bottoms (2650 m depth) offshore Veracruz State, southern Gulf of Mexico. The new species can be differentiated as follows: accessory flagellum 2-articulate; antenna 2 flagellum 4-articulate; pereopods 5-6 with long curved seta on dactylus; rami of uropod 1 subequal in length; uropod 3 ramus longer than peduncle, unarticulated; pleopods 1-3 as long as pleonal segments; maxilla 1 inner plate with one tiny seta distally; mandible without palp; molar poorly developed; pleopods reduced; telson as a fleshy ovoidal lobe with two slender dorsal setae. A table and a map featuring the nine ingolfiellids recorded in the Gulf of Mexico, the Caribbean Sea, and eastern Florida are also provided. The new species increases the number of Ingolfiella species to 35 worldwide, representing the second record of ingolfiellids from the Gulf of Mexico.

Abstract: Image-Based Flow Cytometry (IBFC) is a potent tool for the detailed analysis and quantification of cells in intricate samples, facilitating a comprehensive understanding of biological processes. This study leverages the ResNet50 model to address IBFC’s object-defocusing issue, an inherent challenge when imaging a 3D object with stationary optics. A dataset of 604 mouse sperm IBFC images (both bright field and fluorescence) underpins the exceptional capability of the ResNet50 model to reliably identify optimally focused images of the sperm head and flagella (F1-Score of 0.99). A U-Net model was subsequently employed to accurately segment the sperm head and flagellum in images selected by ResNet50. Notably, the flagellum presents a significant challenge due to its sub-diffraction transversal dimensions of 0.4 to 1 micrometers, resulting in minimal light intensity gradients. The U-Net model, however, demonstrates exceptional efficacy in precisely segmenting the flagellum and head (dice = 0.81). The combined ResNet50/U-Net approach offers significant promise for enhancing the efficiency and reliability of sperm analysis via IBFC, and could potentially drive advancements in reproductive research and clinical applications. Additionally, these innovative strategies may be adaptable to the analysis of other cell types.

Culicoides truuskae Labuschagne and Meiswinkel sp. n. is described and illustrated in both sexes from material collected in South Africa and Namibia. It is restricted to the xeric western margin of the subcontinent, occurring in Fynbos, Nama-Karoo and Succulent Karoo ecoregions in South Africa and Desert and Savanna ecoregions in Namibia experiencing < 600 mm of rainfall annually. Culicoides truuskae sp. n. is part of the Afrotropical 'plain-wing' Culicoides in which the wing lacks a distinguishing pattern of light and dark spots; the diagnostic dark smudge that traverses wing cell r3 may result in C. truuskae sp. n. being misidentified as the sympatric but phyletically unrelated Culicoides herero (Enderlein) - (of the Similis group, subgenus Oecacta Poey). Additionally, this study is the first description of the male of C. herero. C. truuskae sp. n. and Culicoides coarctatus Clastrier and Wirth share similar characters in the male genitalia, although the two species are separable on wing pattern and female flagellum sensilla coeloconica (SCo) distribution. The breeding habitat and adult female blood-feeding preferences of C. truuskae sp. n. are not known. A maximum likelihood phylogenetic tree, using mitochondrial cytochrome c oxidase I (COI) sequence data, is provided to further clarify the relationship between C. truuskae sp. n., C. coarctatus and C. herero. Extensive light trap data, collected over 30 years, are used to map the distribution ranges of C. truuskae sp. n., C. coarctatus and C. herero in Southern Africa. CONTRIBUTION: The description of this new species and the description of the male of C. herero increases our understanding of the diversity and distribution of Culicoides species in southern Africa.

Abstract This review explores the structure and biogenesis of bacterial flagella, highlighting their structural diversity in various bacterial models. It delves into how these structures, originating from a conserved structural flagellar nucleus (NEFC), have evolved to adapt to different functions and capabilities. This diversity plays a crucial role in each species’ ability to thrive in specific ecological niches. The bacterial flagellar motor is a complex apparatus comprising a rotor and a stator embedded in the cell envelope. Recent advancements have revealed the incorporation of new components that enhance its functionality. These components include additional rings or discs beyond those found in the NEFC. These additional elements cover or interact with the basal body and stator, resulting in greater efficiency and rotational speed by facilitating the recruitment of more stators or stabilizing their connection to the rotor. Furthermore, variations are observed in the hooks or filaments, with modified flagellins that possess unique enzymatic properties. The increasing number of bacterial models studied, coupled with advanced visualization techniques such as cryo-microscopy, has unveiled the remarkable diversity in flagellar architecture. This, in turn, has led to a paradigm shift in our understanding of the assembly and operation of the flagellar motor. In conclusion, the field of bacterial flagellum research is experiencing a period of rapid progress, driven by a growing body of evidence and the development of innovative visualization techniques. This progress enhances our understanding of this vital bacterial structure and its role in bacterial adaptation and function.

Resumen Esta revisión muestra la estructura y biogénesis del flagelo bacteriano y su diversidad estructural en numerosos modelos bacterianos. Se expone, cómo a partir de un núcleo estructural flagelar conservado (NEFC), se han diversificado las estructuras que modifican su capacidad y función. Esta variabilidad se sabe, participa en la habilidad de adaptación de cada especie a un nicho específico. El motor flagelar bacteriano es una estructura compleja constituida por un rotor y un estator, los cuales se encuentran embebidos en la envoltura celular. La incorporación de nuevos componentes, que contribuyen a su funcionamiento, incluyen la presencia de anillos o discos adicionales a los presentes en el NEFC, cubriendo o interactuando con el cuerpo basal y el estator, lo que permite una mayor eficiencia y velocidad de rotación al favorecer el reclutamiento de un mayor número de estatores, o que permiten la estabilización de estos al rotor. Además, podemos encontrar ganchos más robustos o filamentos con flagelinas modificadas que presentan propiedades enzimáticas. El aumento de los modelos bacterianos estudiados junto con el avance de las técnicas de visualización como la crio-microscopía, han permitido describir la gran riqueza existente en las variaciones de la arquitectura flagelar lo que ha llevado a un cambio de paradigma al lograr entender algunos de los procesos que permiten el ensamblaje y función del motor flagelar. Todo lo mencionado evidencia el momento de rápido progreso que el campo de estudio del flagelo bacteriano muestra recientemente.

ABSTRACT The sensilla of insects play important roles in odor, taste, the feeling environment, and some sensory functions, which are closely associated with insect host locating, feeding, habitat searching, courtship, mating, and oviposition. In this study, we used a scanning electron microscope to observe the external morphology of nymph and adult Frankliniella occidentalis sensilla on antennae, compound eyes, legs, mouthparts, wings and tail. The results show that three main types of sensilla are located on the antennae: sensilla trichodea, sensilla chaetica, and sensilla basiconica. Among them, sensilla trichodea are the most abundant, followed by sensilla chaetica. Sensilla basiconica on antennae are divided into seven sub-styles, including longer sensilla (L-sensilla basiconica, long sensilla basiconica), shorter sensilla (angle sensilla basiconica, bud sensilla basiconica), and thicker and bigger sensilla (stick sensilla basiconica, fork sensilla basiconica, and finger sensilla basiconica). Only two fork sensilla basiconica were found, located on the dorsal part of the first flagellum subsegment and the ventral part of the second flagellum subsegment, respectively. Seven sensillum types were found on the legs: sensilla trichodea, sensilla chaetica, sensilla basiconica, sensilla ear washing buob-shaped, mamillary sensilla, sensilla campaniform, and Böhm bristle. About 60% of them are sensilla chaetica. Only one sensillum type was found on compound eyes: sensilla chaetica. In addition, some sensillum types were also found on the mouthparts, wings and tail, respectively. In the study, we observed the type, morphology, and distribution of sensilla on antennae, legs, compound eyes, and other regions of nymph and adult F. occidentalis, forming a base for future electrophysiological and behavior experiments on F. occidentalis.

Resumen El género Eudevenopus incluye 4 especies válidas, son habitantes de aguas relativamente poco profundas en ambos lados de América. En este artículo se describe e ilustra una quinta especie, recolectada con una trampa de luz en Sisal, península de Yucatán. Eudevenopus winfieldi sp. nov. puede distinguirse de otras especies del género por el dactilo del pereópodo 7, que es tan largo como el própodo, el artejo 1 de la antena 1 del flagelo del macho con 2-4 estetes, un peine de 6 setas pectinadas distales en el margen posterodistal del carpo del gnatópodo 2, el pedúnculo del urópodo 3 tiene una sola seta intermedia robusta en el margen externo. También se proporcionan una clave de identificación y una tabla comparativa para contrastar la especie nueva con E. honduranus, que es la especie reconocida más cercana.

Abstract The genus Eudevenopus includes 4 valid species, inhabitants of relatively shallow waters in both sides of America. A fifth species, collected with a light trap in Sisal, Yucatán Peninsula is described and illustrated in this paper. Eudevenopus winfieldi n. sp. can be distinguished from other species in the genus by the pereopod 7 dactylus, which is as long as propodus, article 1 of flagellum antenna 1 of the male with 2-4 aesthetascs, a comb of 6 distal pectinate setae on the posterodistal margin of the carpus of gnathopod 2, and the uropod 3 peduncle, which has a simple robust intermediate seta on the external margin. An identification key and a comparative table are also provided to contrast the new species from E. honduranus, which is the closest recognised species.

Resumen En años recientes se han realizado grandes avances en el estudio de la estructura y regulación del flagelo bacteriano. Aun con su amplia diversidad, todos los sistemas flagelares están compuestos por un cuerpo basal, un gancho y un filamento. El ensamblaje flagelar es escalonado y se encuentra altamente regulado. El último paso en la biogénesis flagelar es el ensamblaje del filamento, estructura compuesta por subunidades de flagelina, el componente flagelar más abundante. La síntesis del filamento representa un alto gasto metabólico, por lo tanto, se encuentra estrictamente regulado. En esta revisión se presentan los avances más relevantes sobre la regulación de la expresión de la flagelina en los niveles transcripcional, postranscripcional y postraduccional a través de los grupos bacterianos más representativos.

Abstract Over the last few years, great breakthroughs have been made in the study of the structure and regulation of the bacterial flagellum. Despite their diversity, all flagellar systems share a basal body, a hook, and a filament. The flagellar assembly is tiered and tightly regulated. The final step in the flagellar biogenesis is the filament assembly composed by flagellin subunits, the most abundant flagellar protein. The filament synthesis is metabolically expensive hence, is tightly regulated. In this review, we present the most relevant advances in the understanding of the regulatory mechanisms of flagellin expression at the transcriptional, posttranscriptional, and posttranslational level across the most representative bacterial groups.

Resumen En 1909, Carlos Justiniano Chagas describió por primera vez las manifestaciones clínicas de la enfermedad de Chagas. El parásito hemoflagelado Trypanosoma cruzi (agente) se caracteriza por la presencia de un flagelo, y en su citoplasma presenta organelos como el citostoma, los glicosomas, los reservosomas y un núcleo. El ciclo de vida de T. cruzi se inicia cuando el vector defeca sobre la piel del hospedero sus heces contienen tripomastigotes metacíclicos, que infectan las células del vertebrado. Los vectores de esta enfermedad pertenecen a la Subfamilia Triatominae, insectos hematófagos, nocturnos y con la capacidad de localizar a sus hospederos mediante la detección del calor. T. cruzi tiene efectos en la biología del insecto triatomino, en su comportamiento, en el funcionamiento del intestino, su sistema inmunológico y la microbiota asociada. En el hospedero mamífero, el parásito activa la respuesta inmune innata, y las citocinas tienen un papel clave para controlar la infección o bien evolucionar a la cronicidad. T. cruzi presenta una amplia diversidad genética, y bajo condiciones de laboratorio se han demostrado sus diferentes grados de virulencia y tropismo hacia los órganos blanco; sin embargo, no existe una asociación clara entre las cepas y el comportamiento clínico de la enfermedad. Esta revisión aborda la historia del descubrimiento de la enfermedad de Chagas y discute aspectos recientes sobre la biología de T. cruzi para comprender la dinámica de su transmisión.

Abstract In 1909, Carlos Justiniano Chagas first described the clinical manifestations of Chagas disease. The hemoflagellate parasite Trypanosoma cruzi (agent) is characterized by the presence of a flagellum and of a cytostome, glycosomes, reservosomes, and a nucleus in its cytoplasm. The life cycle of T. cruzi begins when a vector defecates on the skin of a host; the feces contain metacyclic trypomastigotes, which infect vertebrate cells. The vectors of this disease are members of the subfamily Triatominae, nocturnal, hematophagous insects capable of locating hosts by heat detection. T. cruzi infection has effects on the biology of the triatomine insect, its behavior, gut function, immune system, and associated microbiota. In the mammalian host, the parasite activates innate immune responses, and host cytokines are key to either control the infection or progress to chronicity. T. cruzi exhibits a wide genetic diversity, and while it has been proved under laboratory conditions to show varying degrees if virulence and organ tropism, no clear association has been found between specific strains and the clinical picture of the disease. This review addresses the history of the discovery of Chagas disease and discusses recent aspects of T. cruzi biology that provide insight into the dynamics of transmission.

Abstract A new species, Actinimenes koyas sp. nov. (Decapoda: Palaemonidae) was collected at a depth of 1.0-2.0 m from the coral atoll of Agatti Island, Lakshadweep, Arabian Sea. The species was associated with the sea anemone, Heteractis magnifica (Quoy and Gaimard, 1833). It is the second representative of the genus Actinimenes Ďuriš and Horká, 2017 described from the Arabian Sea. Actinimenes koyas sp. nov. is closely related to A. ornatellus in terms of morphological traits. Actinimenes koyas sp. nov. is distinguished from Actinimenes ornatellus (Bruce, 1979) by the presence of a biramous outer antennular flagellum with three proximal segments fused, a shorter free ramus consisting of 7 to 8 segments with 12-14 groups of aesthetascs, a fourth thoracic sternite with V-shaped median incision and features of the telson and third maxilliped. The present new species is easily distinguished from the other three described species in the genus Actinimenes by the structural variation in the fourth sternal plate with a median notch. Additionally, a phylogenetic analysis inferred by Maximum Likelihood using the mitochondrial genes COI and 16S rRNA shows a close relationship of Actinimenes koyas sp. nov. with Actinimenes inornatus (Kemp, 1922). Pairwise genetic distances estimated using the COI and 16S data provided divergences between A. koyas sp. nov. and other congeneric species.

Abstract Spelunconiscus Campos-Filho, Araujo and Taiti, 2014 is a monotypic genus of the family Styloniscidae represented by a troglobitic species, Spelunconiscus castroi Campos-Filho, Araujo and Taiti, 2014, from the cave MOC-32, in the state of Minas Gerais, southeastern Brazil. New representatives of this family were found in three additional caves, which revealed a new species, Spelunconiscus septemlacuum sp. nov., from Taboa and Tatuzinhos caves and a new occurrence for the type-species in Retiro cave. The original diagnosis of Spelunconiscus is emended due to the discovery of a spur-like structure in the male pereopod VII ischium, as well as some supplementary traits that have not been previously considered. Spelunconiscus septemlacuum sp. nov. differs from S. castroi in the number of articles of the antennal flagellum, in the proportion between this flagellum and 5th article of peduncle of antenna, in the size of maxilliped endite, in the morphology of male pleopod II and in body size. A discussion is provided for both taxonomic and ecological concerns.

Abstract With over 10 recognized genera, Panopinae is the most diverse subfamily within the family Acroceridae in the Neotropical region. In Chile, it is represented by 18 species grouped in 3 genera, Archipialea Schlinger, Arrhynchus Philippi and Lasia Wiedemann. In this study we report the genus Coquena Schlinger for the first time for the Chilean territory,and describe Coquena coquimbensis sp. nov. This new species can be distinguished from the only previously known species of the genus, C. stangei Schlinger, based on of the position of the antenna, length of the flagellum and by color differences on the ocular, thoracic and ocellar triangle pilosity. A key to the Chilean genera of Panopinae is provided.

Resumen Con más de 10 géneros reconocidos, Panopinae es la subfamilia más diversa dentro de la familia Acroceridae (Diptera) en la región Neotropical. En Chile, esta subfamilia se encuentra representada por 18 especies agrupadas en 3 géneros, Archipialea Schlinger, Arrhynchus Philippi y Lasia Wiedemann. En este estudio se reporta por primera vez el género Coquena Schlinger para el territorio chileno y se describe a C. coquimbensis sp. nov. Esta especie nueva se distingue de la única que era conocida para el género, C. stangei Schlinger, por la posición de las antenas, la longitud del flagelo y por diferencias en la coloración de la pilosidad ocular, del tórax y del triángulo ocelar. Se presenta una clave para distinguir los 4 géneros de Panopinae conocidos para Chile.

RESUMO Os objetivos do presente estudo foram analisar a ultraestrutura do espermatozoide do jundiá amazônico e avaliar a sua criopreservação com três agentes crioprotetores (metanol 10%, DMSO 10% e etilenoglicol 10%) e duas soluções ativadoras (NaCl 0,29% e NaHCO3 1%). Como diluente, foi utilizada uma solução de glicose a 5%, sendo o sêmen envasado em palhetas de 0,25mL e congelado em vapor de nitrogênio (botijão dry shipper). No sêmen fresco, o espermatozoide apresentou comprimento de 25,46±2,54μm, cabeça esférica (1,51±0,18μm), ausência de acrossoma, peça intermediária com formato cônico (0,93±0,17μm), ligeiramente assimétrica, com presença de vesículas, e flagelo único (21,48±2,45μm). O sêmen descongelado apresentou valores mais altos (P<0,05) para duração, vigor e taxa de motilidade espermática com os crioprotetores metanol 10% e DMSO 10%. A duração da motilidade espermática foi maior (P<0,05) com o ativador NaHCO3 1% (21-96 s). O sêmen de Leiarius marmoratus criopreservado com DMSO e metanol apresentou, respectivamente, 7,32±4,21% e 8,94±6,69% de taxa de motilidade. No entanto, os resultados não foram satisfatórios para estabelecer um protocolo para a espécie.

ABSTRACT The aims of this study were to describe the spermatozoon ultrastructure and to evaluate the sperm cryopreservation of the amazon catfish with three cryoprotectant agents (10% methanol, 10% DMSO, and 10% ethylene glycol) and two activator agents (0.29% NaCl and 1% NaHCO3). Glucose 5% extender was used as a diluent solution and sperm loaded in 0.25 straws was frozen in nitrogen vapor (dry shipper). Fresh spermatozoon was 25.46±2.54μm long, the head was spherical (1.51±0.18μm) with no acrosome, the midpiece was cone shaped (0.93±0.17μm) with presence of vesicles, slightly asymmetric, and the flagellum was single (21.48±2.45μm). Post-thawed semen presented higher values (P< 0.05) for duration, vigor and sperm motility rate with cryoprotectants 10% methanol and 10% DMSO. The duration of sperm motility was longer (P< 0,05) when triggered in 1% NaHCO3 (96-21 s). Leiarius marmoratus semen cryopreserved with DMSO and methanol, presented respectively 7.32±4.21% and 8.94±6.69% of motility. However, the results were not satisfactory to establish a protocol for the specie.

Abstract Leishmaniasis is a neglected disease caused by Leishmania. Chemotherapy remains the mainstay for leishmaniasis control; however, available drugs fail to provide a parasitological cure, and are associated with high toxicity. Natural products are promising leads for the development of novel chemotherapeutics against leishmaniasis. This work investigated the leishmanicidal properties of ethanolic extract of Croton blanchetianus (EECb) on Leishmania infantum and Leishmania amazonensis, and found that EECb, rich in terpenic compounds, was active against promastigote and amastigote forms of both Leishmania species. Leishmania infantum promastigotes and amastigotes presented IC50 values of 208.6 and 8.8 μg/mL, respectively, whereas Leishmania amazonensis promastigotes and amastigotes presented IC50 values of 73.6 and 3.1 μg/mL, respectively. Promastigotes exposed to EECb (100 µg/mL) had their body cellular volume reduced and altered to a round shape, and the flagellum was duplicated, suggesting that EECb may interfere with the process of cytokinesis, which could be the cause of the decline in the parasite multiplication rate. Regarding possible EECb targets, a marked depolarization of the mitochondrial membrane potential was observed. No cytotoxic effects of EECb were observed in murine macrophages at concentrations below 60 µg/mL, and the CC50 obtained was 83.8 µg/mL. Thus, the present results indicated that EECb had effective and selective effects against Leishmania infantum and Leishmania amazonensis, and that these effects appeared to be mediated by mitochondrial dysfunction.

RESUMEN La criopreservación ha sido recientemente aplicada a gametos y tejidos coralinos obteniendo resultados exitosos que pueden ser utilizados para la conservación y la restauración de arrecifes de coral. En este artículo, se determinó la morfología espermática del coral Orbicella faveolata y la viabilidad de la criopreservación del esperma utilizando una combinación de crioprotectores intracelulares (1,2-Propadiol) y extracelulares (leche) en dos tratamientos de congelación durante 24 h. Los espermatozoides maduros tienen una cabeza con forma triangular de 4.10 ± 0.69 µm (promedio ± DS) y un flagelo largo ( 43.24 ± 7 .99 µ m). El esperma fresco permanece viable y motil por más de cinco horas después de ser liberado de las bolsas gaméticas. Todos los componentes evaluados después de descongelado el esperma (morfología, motilidad y viabilidad) no mostraron diferencias significativas con el esperma fresco. Este estudio es el primer registro de criopreservación para el esperma de O. faveolata; sin embargo, es necesario realizar más investigaciones con el fin de incrementar el éxito del protocolo de criopreservación para que este pueda ser aplicado a mayor escala.

ABSTRACT Cryopreservation has been recently applied to coral gametes and tissue with successful results that can be applied for different purposes on coral conservation and restoration. In this study, we decided to determine the sperm morphology of the coral Orbicella faveolata and assess the feasibility of sperm cryopreservation using a combination of intracellular (1,2-Propadiol) and extracellular (milk) cryoprotectants, and two frozen treatments for 24 h. Mature spermatozoa had a triangular-like head shape measuring 4.10 ± 0.69 µm (mean ± SD) and long flagellum (43.24 ± 7.99 µm). Fresh sperm remained viable and mobile for more than five hours after being released from the gamete bundles. After cryopreservation, all post-thaw sperm components assessed (morphology, motility and viability) showed no difference in contrast to fresh sperm. This study is the first report of cryopreservation of O. faveolata sperm, however further research is needed to increase the success of the cryopreservation protocol for broad-scale application.