OMAR HERNANDO AVILA-POVEDA: (AVILA-POVEDA OH)

The oviducal glands (ODG) play a crucial role in octopus reproduction. Herein, structural changes of each section of the ODG of Octopus mimus are described histologically throughout the gonad development stages (GDS). To do this, the epithelial height, stereociliated or non-stereociliated epithelium, nucleus type (pycnotic or non-pycnotic), epithelial secretions and the value range of the macroscopic maturity index (MaMI), which directly involves ODG status, were measured. The ODG are internally constituted of two glandular units (central and peripheral glands) and one set of receptacles (the spermathecae). High epithelia (40 to 80 μm) were observed in both gland units during periods with low MaMI values (< 0.1) corresponding to III-mature and IV-pre-spawning. The stereociliated epithelium was only apparent in II-maturing and III-mature in both gland units. The nuclei were noticeably pycnotic in the central gland during III-mature, IV-pre-spawning and V-spawning, but pycnotic in the peripheral gland only during VI-depletion. The epithelium was disorganised during VI-depletion, while sulphated acid mucin was only present during III-mature in the central gland. The epithelium transformations during the GDS are related to the functions of the gland units and to their multiple secretions. The ODG histology complements the GDS and provides better reproductive status assessment.

Laboratory studies have demonstrated that high temperatures inhibit spawning of Octopus maya; therefore, in oceanic warming scenarios the population dynamics may be affected. The aim of the present study was to go beyond laboratory studies under controlled temperatures to examine the possible relationship between large-scale thermal patterns and reproductive season (represented by functional maturation) of O. maya in the wild on the continental shelf of the Yucatan Peninsula, where it is endemic. The macroscopic maturity index (MaMI) was obtained in females, and reproductive complex index (RCI) and number of spermatophores in males. Associations between these indices and environmental temperature regime were inferred by sampling octopuses in an upwelling zone (Z-I), a transition zone (Z-II) and a nonupwelling zone (Z-III). The reproductive condition of O. maya differed between Z-I and Z-III. In all zones, the proportion of adults showing functional maturity was highest in both females (MaMI: 36–71% of values ≤0.2) and males (RCI: 12–40% of values ≥0.9; 41–49 spermatophores per octopus) during the season of winter storms ('nortes' season, November–February), when the sea-surface temperature oscillates around 25 °C. In Z-I, some individuals were functionally mature throughout the year, likely due to low temperatures maintained by summer upwelling. Zone-I had the greatest proportion of functionally mature males (up to 40% of adults in 'nortes' season) and the greatest number of spermatophores (mean 43–49 spermatophores per octopus in all seasons). Females in Z-III (without upwelling) were functionally mature mainly in the 'nortes' season when water temperature decreased, with only a small proportion mature in the rest of the year when water temperatures reached 31 °C. As predicted by laboratory studies, water temperature below 27 °C appears to be favourable for the functional reproductive maturation of wild O. maya.

Cyanobacteria appear to have direct relations with mollusks in several aspects. This is the first time, distinguishing gram-negative cyanoprokaryotic Synechococcus elongatus as bright yellow-gold autofluorescence by Lillie's and Hiss’ staining methods on paraffin-embedded tissues of Crassostrea gigas. Three diets: cyanoprokaryotes, cyanoprokaryotes with microalgae, and only microalgae were evaluated. Cyanoprokaryotes were intact, densely bundled, and immersed in the cytosol of the digestive gland, connective tissue, mantle, and gonad of C. gigas, revealing an accumulation systemic without tissue damage observed by histology. Unexpectedly, cyanoprokaryotes were slightly most accumulated with microalgae diet by each of the tissues of the C. gigas than with any other diets. Cyanoprokaryotes tend to be in mean slightly higher in the digestive gland than in any other tissues respectively for each diet, although these values are closely similar to connective tissue. A possible order of exposure of the oyster tissues to accumulation of cyanoprokaryotes was digestive gland, connective tissue, mantle, and gonad. Thereby, the digestive gland could be the major target tissue for the accumulation. Our observations provide a valuable insight regarding the ability of cyanoprokaryotes to penetrate, spread, and remain inside the oyster tissues, suggesting for S. elongatus: (1) a pre-accumulation in oyster tissues from the natural environment, (2) a phagocytosis and/or endocytosis process rather than ingestion and extracellular digestion, (3) an apparent cellular division in the cytosol of oyster tissues, (4) an apparent inter-tissue movement, and (5) a possible endosymbiosis between C. gigas and S. elongatus. Hereby, it is possible that S. elongatus have a well-developed host-endobiont relationship with oysters, and thereby support future work toward a description of the escape and spreading mechanisms of S. elongatus inside the tissues of mollusks, and put forward questions as why it is there?, and are the cells active or inactive?

Citation analysis has become an essential tool for research and academic effectiveness evaluation of universities. However, authorship identity has long been difficult to resolve in bibliometric analyses for many scientific fields, where performance of algorithms against human judgment is far from universal. Now with the boom of authors with compound names (mainly, Latino researchers and from Portuguese language countries) in scientific publications, clustering methods continue lowering their performance, due to completely forgetting the context and order of names (first name“s” and last name“s”) of each author in the publication (authorship identity). These kinds of mistakes affect visualization of publications, decreasing the likelihood of finding a given article by a specific author and generating bad quotations in the online systems. This has led to an unsuitable registration and unsuitable grouping of author names “ambiguous authorship identity” of each scientific publication. This process requires more work, time, attention, and accountability on the part of authors, reviewers, journal editors, and providers of bibliographic databases. These errors can be corrected by cross-referencing with each full original article, using manual checks and without ignoring the names issue at the moment of drafting and/or reviewing a manuscript. This paper seeks to raise awareness on how to write author names, highlighting the way in which they are being cited and self-citing the name of authors and co-authors in the publications.

Hoffmannola hansi (Mexican intertidal leather slug) is traditionally reported as an endemic species to the Gulf of California, Mexico. However, its presence in the southern Mexican Pacific has been mentioned in regional checklists and reports. Here we provide new records of H. hansi populations from at least 3 locations from Oaxaca, Mexico. The anatomical characteristics useful for H. hansi identification are described for both, living and preserved specimens. Specimen’s reports from the Gulf of California to Oaxaca, Mexico, are mentioned, yielding a revised distribution throughout the Mexican Pacific. A map with the wider geographic distribution of H. hansi is also updated. Therefore, this species is not “endemic” to the Gulf of California, but is distributed throughout the Mexican Pacific. However its distribution is discontinuous with the possible existence of 2 cryptic species geographically separated by the Sinaloan gap: 1 in the North (Gulf of California) and 1 in the South. Additional work is needed to explore in more detail the complete geographical range of H. hansi populations on the entire Mexican Pacific Coast

This study describes and recognises, using histological and microscopical examinations on a morphometrical basis, several gonad traits through the early life stages of Chiton articulatus and C. albolineatus. Gonadal ontogenesis, gonad development stages, sexual differentiation, onset of the first sexual maturity, and growth sequences or “early life stages” were determined. In addition, allometry between lengths and body weight pooled for both sexes per each chiton were calculated using equation Y = aXb. A total of 125 chitons (4≤TL≤40 mm, in total length “TL”) were used. All allometric relations showed a strong positive correlation (r), close to 1, with b-values above three, indicating an isometric growth. Gonadal ontogenesis and gonad development stages were categorised into three periods (“Pw” without gonad, “Pe” gonad emergence, and “Pf” gonadal sac formed) and four stages (“S0” gametocytogenesis, “S1” gametogenesis, “S2” mature, and “S3” spawning), respectively. Compound digital images were attained for each process. Periods and stages are overlapped among them and between species, with the following overall confidence intervals in TL: Pw 6.13–14.32 mm, Pe 10.32–16.93 mm, Pf 12.99–25.01 mm, S0 16.08–24.34 mm (females) and 19.51–26.60 mm (males), S1 27.15–35.63 mm (females) and 23.45–32.27 mm (males), S2 24.48–40.24 mm (females) and 25.45–32.87 mm (males). Sexual differentiation (in S0) of both chitons occurs first as a female then as a male; although, males reach the onset of the first sexual maturity earlier than females, thus for C. articulatus males at 17 mm and females at 32 mm, and for C. albolineatus males at 23.5 mm and females at 28 mm, all in TL. Four early life stages (i.e., subjuvenile, juvenile, subadult, and adult) are described and proposed to distinguish growth sequences. Our results may be useful to diverse disciplines, from developmental biology to fisheries management.

""Abstract.
The polyplacophoran Chiton articulatus Sowerby, 1832, is distributed along the tropical Pacific coast of Mexico and has been collected for generations in an artisanal manner for bait or as a complement in domestic cookery of coastal inhabitants; nevertheless, recently, some restaurants are offering this chiton to the tourists as a gourmet and aphrodisiac food, thus becoming of potential economic interest. This study explores in a population of C. articulatus adults from Oaxaca, southern Mexican Pacific, the changes in morphometry and in somatic and reproductive indices throughout one year, reporting on five reproductive indices, five somatic indices, body shape (BS), and length-weight relationships. An attempt is made to elucidate the energetic trade-off between somatic and reproductive tissues, including an assessment of whether these can be estimated from noninvasive indices. Somatic indices diminished considerably as gonad development proceeded, thus showing an inverse relationship with reproductive indices. Body mass index (BMI, i. e., physical conditions) patterns revealed that chitons were overweight (in the sense of high accumulation of lipids in the gonad) during reproductive seasons. The C. articulatus body was mainly oval-shaped throughout the whole sampling period. The slope of the length-weight regressions indicated an allometric growth (b, between 2.2 and 2.8). Gonad development is fueled by energy and nutrients derived from food rather than from reallocation of somatic reserves, although some somatic tissue constituents (in particular from foot) of reproducing adults may be mobilized in the short-term to meet nutrient and energy needs for reproduction. Reproductive seasons of C. articulatus according to the measured indices, occurred around May (late-spring) and again around August-September (late-summer), and these periods were correlated with maximum sea surface temperatures. The measurement of BS together with BMI can be used nearly as effectively as the more invasive reproductive indices to estimate reproductive seasonality.

Resumen.
El poliplacóforo Chiton articulatus Sowerby, 1832, se distribuye a lo largo de la costa del Pacífico tropical de México, y ha sido recolectado por generaciones de una manera artesanal para usar como cebo o como un complemento en la cocina doméstica de las poblaciones humanas costeras; sin embargo, recientemente, algunos restaurantes están ofreciendo este quitón al turista como un comida gourmet y afrodisíaca, favoreciendo un potencial interés económico. Este estudio explora en una población de adultes de C. articulatus de Oaxaca, en el sur del Pacífico mexicano, los cambios en morfometrías y en índices somáticos y reproductivos a lo largo de un año; reportando cinco índices reproductivos, cinco índices somáticos, la forma del cuerpo, y las relaciones talla-peso. Se hace un intento por esclarecer el intercambio energético entre los tejidos somáticos y reproductivos, incluyendo una evaluación de si estos pueden ser estimados a partir de índices no invasivos. Los índices somáticos disminuyeron considerablemente cuando el desarrollo de las gónadas procedió, y mostró una relación inversa con los indices reproductivos. El patrón del índice de masa corporal (i.e., condiciones físicas) mostró que los quitones tuvieron sobrepeso (en el sentido de alta acumulación de lípidos en la gónada) durante la temporada reproductiva. El cuerpo de C. articulatus fue principalmente en forma de óvalo en todo el periodo de muestreo. La pendiente de las regresiones de talla-peso indica un crecimiento alométrico (b, entre 2,2 y 2,8). El desarrollo de las gónadas se abastece de la energía y los nutrientes derivados del alimento en lugar de la reasignación de las reservas somáticas, aunque algunos componentes de los tejidos somáticos (en particular del pie) de adultos en reproducción pueden ser movilizados en el corto plazo para reunir los nutrientes y energía necesaria para la reproducción. Las temporadas reproductivas de C. articulatus de acuerdo con los índices, sucede alrededor de mayo (finales de la primavera) y alrededor de agosto-septiembre (a finales del verano), y estos periodos guardan correlación con la máxima temperatura superficial del mar. La forma del cuerpo junto con el índice de masa corporal, pueden ser usados casi tan efectivamente como los índices reproductivos invasivos para estimar temporada reproductiva.
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The reproductive biology of Ophiocoma aethiops and O. alexandri was analyzed based on monthly time-series samples from May 2009 to April 2010 at Estacahuite Bay, Oaxaca,  in the Mexican tropical Pacific Ocean. We evaluated the relationship between the reproductive biology of both species and variations of sea-bottom temperature, salinity, pluvial precipitation, photoperiod (light hours) and chlorophyll. Sex ratio, gonadosomatic index (GSI), actual fecundity and oocyte size were determined. Monthly variations of the environmental factors were compared with variations of GSI. Both species are gonochoric ophiuroids and the ratio of males to females (1:1) was not significantly different throughout the year. There were significant differences in GSI values between the 2 species, but temporal variation patterns were similar. Gametogenesis showed synchrony among males and females and 4 stages were recognized for both sexes. Spawning occurred in females of O. aethiops from May to November and from April to December in O. alexandri. Main spawning for males of both species occurred from May to December, although there was always availability of mature spermatozoa. Mean oocyte size was 32 to 58 µm for O. alexandri and 47 to 63 µm for O. aethiops. Mean ± SD fecundity was 3.03 ± 1.72 million vitellogenic oocytes per female for O. aethiops and 1.61 ± 0.99 million for O. alexandri. The reproductive patterns of O. aethiops and O. alexandri are influenced by the local oceanic dynamics, as has been reported for other echinoderm species in the area, but they also have a high genetic (endogenous) element, because the observed patterns resemble those determined for the Panamian populations of these 2 species.

The reproductive cycle of the Queen Conch, S. gigas, in the Archipelago of San Andres, Providencia and Santa Catalina, Colombia, was estimated during a 1-year period (February 2003– January 2004) from monthly observations on histological sections of gonads collected from sexually mature individuals. The resting, gametogenic, mature, and post-spawning stages were present almost all year long, while spawners (or "gamete producers" as S. gigas does not spawn into the water but copulates) appeared only twice, from March to April (6% males and 20% females) and in September (6% males, 43% females). The results of our histological analyses are congruent with those of previous works on S. gigas in San Andres Archipelago based only in mating and egg-laying behaviors, and in the presence of egg-masses as proxies for spawning. The current fishing season of Queen Conch in San Andres Archipelago extends from November 1 to May 31, according to Resolution No. 179 of May 5, 1995, and overlaps with the first reproductive event of this species. As harvesting egg-laying females during March–April could place the recovery of the population at risk, we suggest two possible scenarios to modify the current fishing regulation: a) reducing the fishing season from November 1 to March 1, and b) opening two fishing seasons per year, one from November 1 to March 1 and the other from June 1 to July 31. The success of any of these management options can only be evaluated by implementing a monitoring plan in San Andres Archipelago. This simple procedure will help protect this species, improve its sustainability through time, and guarantee the availability of the resource to local fishermen.

The main objective of the current study was to determine an optimal dosage of commercial carp pituitary extract (CPE) of the conventional heteroplastic hypophysation technique to induce spawning in the wild caught striped mojarra broodstock Eugerres plumieri under laboratory conditions. We also describe trials testing saline acclimation regimes (changes from 10& to 30&) prior to hormonal induction. For saline acclimation, three treatments were performed: first and second treatments began 1- day after conditioning of broodstock fish with a total duration of the saline changes lasting 1-day and 2-days, respectively. The third treatment began 30-days after conditioning with a 7-day saline regime. After reaching 30&, all fish from the first and second treatments died after the fourth and ninth days, respectively; while the fishes in the third treatment survived more than two years. These fish remain on public exhibit in the ‘‘Mundo Marino’’ Aquarium, Santa Marta, Colombia. Four treatments of hormonal induction were tested on females using a total concentration of 5-mg of CPE per kg of body weight: first, second and third treatments were applied in two hormonal doses that corresponded to 10%–90%, 30%–70% and 40%–60%, respectively, with time intervals between doses of 14-h for the first and second treatment and of 12-h for the third treatment. The fourth treatment was applied in four hormonal doses that it corresponded to 20%–20%– 30%–30% with 12-h time intervals between doses. Only the fishes of the fourth treatment resisted the induction, continued to live and reached spawning artificially. Water temperature remained at 28 ± 1�C and at 30& salinity during the study. The ‘‘dry’’ method of fertilization was used. The fertilized eggs were incubated at 30& and 35& salinities. These eggs reached the Morula early stage, but were later attacked by protozoan. These results suggest that fast changes of saline and limited hormonal dosages do not offer effective results in Eugerres plumieri. This work provided fundamental procedures for the culture and maintenance of live broodstock for striped mojarra in saltwater and/ or coastal lagoon habitats and provides an effective and viable dosage of CPE for artificial spawning and commercial production in this species.

Size at sexual maturity was investigated in 346 queen conch, Strombus gigas, collected from the Archipelago of San Andres, Providencia and Santa Catalina (SAI), Colombia. Size at sexual maturity is defined as the size (based on total shell length and lip thickness) at which 50 % of the population of queen conch sampled had mature and emission gonad developmental stages, based on microscopic (samples of gonads were processed by standardized histological methods). Only 12.14% of whole samples had mature and emission gonad developmental stages. The size at sexual maturity based on total shell length (STmat) was estimated to be STmat=249 mm for females (n=14), STmat=234 mm for males (n=28) and STmat=241 mm for both sexes (n=42). Lip thickness (LTmat) at sexual maturity was estimated to be LTmat=17.5 mm for females, LTmat=13 mm for males and LTmat=13.5 mm for both sexes. STmat and LTmat for females were greater than those estimated for males, according to plot of the cumulative size frequencies. The maximum sizes that had mature gonad stage were 285 mm ST and 24 mm LT for males (n=2) and 280 mm ST and 30 mm LT for females (n=2). The present size restrictions adopted by some countries with queen conch fisheries is 5 mm LT and/or 180-250 mm ST, which is not adequate to protect stocks should they be subjected to heavy fishing pressure. A lip thickness of 13.5 mm or greater appears from this study as to be a better maturity criterion. Therefore, this criterion should be adopted by Caribbean countries as a fisheries management tool in order to protect the queen conch fishery and ensure sustainability of the fishery.

Chiton articulatus is a polyplacophore that lives on the intertidal rocky and is distributed along the Mexican Tropical Pacific (MTP), from southern Sinaloa to Oaxaca, where is an endemic species. Ecologically, it is a key species of rocky coastal ecosystems, due its herbivory that controls the algae growth, and because it is a basibionte for other organisms. It is a gonochoric species and a free spawner with a short time trochophore larvae of (~ six days), before it metamorphoses to settles in rocky substrate; so its dispersal potential is low. These biological and ecological characteristics influence the genetic architecture of populations, promoting a genetic differentiation along its geographical distribution. The objective was to evaluate phylogeographic patterns of C. articulatus along its geographical distribution, for which chiton tissues were collected in seven localities: Mazatlán (Sinaloa), La Cruz de Huanacaxtle (Nayarit), Melaque (Jalisco), Manzanillo (Colima), Lázaro Cárdenas (Michoacán), Acapulco (Guerrero), and Puerto Ángel (Oaxaca). A total of 84 haplotypes were identified of Cytochrome c oxidase subunit I (coI) gene of mitochondrial DNA with 609 bp. The genetic diversity was high for all sampling locations with an average of h = 0.914. The analysis of molecular variance showed a significant genetic differentiation among all sampling locations (ΦST = 0.58, p <0.001), therefore there are 4 subpopulations along the MTP: 1) Mazatlán, 2) La Cruz de Huanacaxtle-Melaque-Manzanillo, 3) Lázaro Cárdenas-Acapulco, and 4) Puerto Ángel. The phylogeographic pattern indicated a divergence between northern and southern localities forming two clusters; also, ancestral haplotypes were located in central localities in both clusters. Due to this, it is possible that migration has occurred from center (Melaque and Manzanillo) towards peripheral (Mazatlán and Puerto Ángel) localities. In addition, the genetic connectivity was mediated by geographical distance between localities (r2 = 0.48, p = 0.011). The historical demography results indicate that almost all localities have suffered sudden population expansions due to bottlenecks and/or a founder effect; the population reductions could be due to geological events such as the closure of the Isthmus of Panama between ~1-3 million years ago in the late Pliocene, and to glaciation events between ~4,000-372,000 years ago between the late Pleistocene and the early Holocene.

Este estudio utiliza como modelo ecológico al quitón Chiton articulatus, una especie endémica de la zona intermareal rocosa, entre los 23-15°N en el Pacífico tropical Mexicano (PTM). Los quitones se han estudiado brevemente con enfoque epibiótico, donde el quitón es el basibionte u organismo sustrato que representa microhábitats disponibles para organismos que viven sobre él (epibiontes). Los estudios epibióticos reflejan microhábitats para comunidades que potencialmente representan la biota de zonas adyacentes, en este caso del intermareal rocoso del PTM. Chiton articulatus como basibionte representa un sustrato importante para la diversidad del intermareal rocoso. La recolección de C. articulatus se está convirtiendo en una pesquería emergente, con lo cual la pesca incidental de la fauna de acompañamiento (epibiontes) podría afectar la estructura de la comunidad intermareal. Aquí se analiza la comunidad epibiótica sobre las placas del quitón, a escala local, regional y temporal en el PTM, bajo el supuesto de que la estructura de la comunidad de epibiontes y endobiontes de C. articulatus no difiere de aquella presente en el ambiente. Siete localidades fueron muestreadas: Mazatlán (23°N), Cruz de Huanacaxtle (20°N), Melaque (19°N), Manzanillo (18°N), Lázaro Cárdenas (17°N), Acapulco (16°N) y Puerto Ángel (15°N). Los muestreos fueron mensuales y simultáneos, 13 por localidad en total, de octubre de 2015 a octubre de 2016 (91 muestras con un promedio de 36±7 quitones cada una). Se analizó la riqueza (S), diversidad (Shannon, H’), uniformidad (Pielou, J’) y dominancia (Simpson, λ’); así como la similitud mediante análisis CLUSTER, MDS y ANOSIM. El registro comprende la densidad de la comunidad epibiótica (organismos/cm2) sobre las placas de 3,313 quitones en total. Para toda la región se observaron 19 morfotipos de invertebrados (18 epibiontes y 1 endobionte). Regionalmente se estimaron alrededor de 21 morfotipos: Chao2=21.50±2.96, Jacknife1=23.95, Jacknife2=24 y Bootstrap=21.59. El modelo de Bootstrap denotó un muestreo suficiente. Regionalmente los morfotipos con alta dominancia fueron tres: balanos Chthamalus spp., lapas Lottia mitella y acrotorácicos Cryptophialus wainwrighti. La densidad de los balanos careció de relación con la latitud, la de lapas disminuyó hacia latitudes menores, mientras que la de acrotorácicos incrementó. A escala local y regional la mayor riqueza (S) y diversidad correspondieron a Mazatlán (23°N) y Manzanillo (19°N). La mayor uniformidad (J’) se presentó en Manzanillo y la mayor dominancia (λ’) en las tres localidades de menor latitud: Lázaro Cárdenas, Acapulco y Puerto Ángel. Localmente, el análisis CLUSTER originó agrupaciones que con el MDS fueron subjetivas, a excepción de Puerto Ángel, que presentó mayor homogeneidad en la estructura de la comunidad epibiótica. A escala regional el CLUSTER, MDS y ANOSIM reflejaron que la comunidad epibiótica forma cinco agrupaciones diferentes (R global=0.559, p=0.001). La comunidad de invertebrados epibióticos de Chiton articulatus coincide con patrones promedio anuales de variables reportadas en la literatura como las mareas, salinidad y temperatura que influyen en la zona costera. Inesperadamente, no se observó un gradiente latitudinal de la biodiversidad (menor diversidad a mayor latitud), pero si se observó que la biodiversidad de invertebrados epibióticos varía a escala local.

The chiton, Chiton (Chiton) articulatus commonly known as "dog tongue" or "sea cockroach" is collected as bait for artisanal fisheries and offered in restaurants like gourmet dish, along the Pacific coast of Mexico, so their consumption is generating a potentially exploitable fisheries and economic interest. Considering reproduction as fundamental in the life history, the economic importance of the resource and that does not have control in their consumption and marketing; studies on aspects of reproductive biology of this species are needed. The aim of this study is to contribute to the basic knowledge of C. (C) articulatus in aspects such as gonadal maturation, reproductive cycle, reproductive season and its relationship with environmental variables, sex ratio and size at maturity (Tm50%). During 2011, 32 adult chitons were monthly collected in Puerto Angel, Oaxaca. A technique for relaxation, fixation and dissection of animals was established. Were taken body measurements (total length: LT, Shell length: LC, total width: AT, Shell width: AC) and total weight (PT). By histological analysis of the gonad the maturation sequence of the female gamete was described, a method for viewing and setting of the gonad maturation stages (GMS) is proposed, and the reproductive cycle was obtained. The reproductive season was characterized with the gonadosomatic index (GSI) and the index of microscopic maturity (IMMi). The sex ratio was calculated. The TM50% were estimated considering the four measurements morphological and the body weight. The gonad of C. (C.) articulatus produces synchronously gametes and the mature oocytes have the "hull egg" characteristic of polyplacophorans. Five gonad maturation stages (GMS) were established and described: I-goniogenesis, II-development, III-mature, IV-spawning, V-rest or recovery. Although C. (C) articulatus is a total spawner and it reproduce throughout all year, the main reproductive season (maturity and spawning) occurs in the second half of the year (July to December), and coincides with the rainy season. The sex ratio during the entire sampling period was 1:1. The TM50% for both sexes was: LT 55.43 mm, LC 50.70 mm, AT 33.27 mm, AC 28.06 mm and PT 11.86 g. It is suggested that a panoramic observation of the gonad for the establishment of GMS. By using different morphometrics for estimating the Tm50% are given more options to establish minimum catch sizes, besides to facilitate data collection in the field. With these results we contribute to the basic knowledge of reproductive biology of Chiton (Chiton) articulatus, which allow proposing future regulatory measures (i.e., closed season and minimum catch size).

The populations of Queen conch are overfishing, requiring the histological studies of its tissue, as the mprphological base to understand the functioning of this organism. The mantle is the responsible tissue to formation of the shell, to chemically and physically interacts with the environment, and it secretes mucus. This work describes the histology of the mantle tissue. The mantle iscomposed by five layer, from the outside (adjacent to the shell) until inside (adjacent to the mantle cavity) are: 1) a squamous epithelium layer, 2) a collagen fiber layer, 3) a connective tisue layer, 4) a layer of muscular tissue, 5) a transitional epithelium. Cytoplasm of the cells of five layer contains collagen.

El tegumento, compuesto por piel y sus apéndices, forma en conjunto un órgano que recubre el cuerpo, ofreciendo a los tejidos blandos subyacentes (dermis, hipodermis) una cubierta de protección contra lesiones. Además, participa en procesos de locomoción, de interacción física y química con el ambiente y de respiración. A fin de conocer la estructura del pie de Strombus gigas, se realizó éste estudio histológico. Esta investigación ilustra la diferencia epitelial encontrada en la suela del pie y en el lado del pie. El epitelio tegumentario del pie presenta: (1) células columnares con disposición lineal, y (2) un epitelio columnar ciliado seudo-estratificado con disposición lobulada y pareada. El epitelio del lado del pie presenta: (1) Epitelio columnar glandular ciliado (glándula pedal) formando pliegues tubulares, y (2) epitelio columnar seudo-estratificado ciliado, formando sinuosidades pareadas con aristas angulares. La glándula pedal presenta una función lubricante, manifestada por la secreción de mucosa y gránulos; en tanto que los lóbulos en la suela del pie actúan como tractor para la locomoción, característica presente en la clase gasterópoda. :::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::: Tegument, made up of skin and its appendices, altogether forms an organ that cover the body, offering to underlying soft tissues (dermis, hypodermis) a protection against injuries. In addition, it contributes in processes of locomotion, physical and chemical interaction with the environment and of breathing. In order to know and to understand the structure of foot of Strombus gigas, the histological study of foot was realized. Different epithelia were observed on the foot sole and the foot side. The epithelia of the sole present: 1) In the dorsal surface is formed by columnar cells with lineal disposition, and 2) in the ventral surface presents pseudostratified columnar ciliated epithelia, forming twinned lobule. Side epithelia present: 1) Glandular columnar ciliated epithelia forming tubular folds and 2) columnar pseudostratified ciliated epithelia forming sinuosities with angular borders. The pedal gland at the side of the foot present a lubricant function, showed by the secretion mucus and grains; whereas the lobules in the sole of the foot, operate as tractor for the locomotion; characteristics that are present in the class gasterópoda.

The main objective of this research was to provide reproductive knowledge of Octopus maya Voss y Solís-Ramírez, 1966, through its life history, as support for the recent Octopus Fisheries Management Plan and its respective action line No. 1.4. (DOF, 28 March 2014), which refers to protect the females in reproduction and its reproductive season.

The chapters of this dissertation consist of individual manuscripts, prepared to submit/send to journals in areas like malacology and/or marine science and/or biology of reproduction, except Chapter 1 (general introduction) and Chapter 6 (general conclusion). Although each chapter is intended to be independent and can be understood without reference to the other, there is an overlap of the subject and all chapters are devoted to reproductive and biological aspects consecutive along the life history of O. maya.

Chapter 1 presents a general introduction on reproductive aspects of octopuses (e.g., structures, maturity, hormonal control), the antecedents about reproductive biology to O. maya, the measurements of fisheries management, and the recently created Plan for Management of Octopus Fisheries with its components and action lines. The objectives of this doctoral research are also reflected.

Chapter 2 describes the development of the gonad during early life of O. maya in terms of histology and morphology, using maintenance octopus (culture), since hatching and through the juvenile stage. In this chapter sets the stage for (a) understand the stages from early life history of O. maya, (b) to recognize the length-weight relationship in an attempt to separate the sexes at the beginning of the life history (for maintenance of culture), (c) to determine whether sexual maturation is a process that starts early in this, and (d) to distinguish sequences of growth or "life history stages", based on consistent terminology: juvenile, sub-adult, and adult.

In the Chapter 3 adapts, develops and validates a solid phase radioimmunoassay, using two components commercially available: 125I-labeled hormones and specific antibody. Also, a hormone extraction protocol was described in order to measure the concentrations of progesterone and testosterone in extracts of gonads octopus O. maya. The third chapter provides the tools and methodology for assessing the reproductive endocrine context of organisms moving a stock (recruitment) reproductive (i.e., adults).

Chapter 4 describes some reproductive aspects of O. maya from Sisal, Yucatan, Mexico, such as: (1) sex ratio, (2) the reproductive cycle based on histology and through five reproductive indices and by frequency of gonad developmental stages, (3) the frequency of non- vitellogenic and vitellogenic oocytes, (4) and the mean size of sexual maturity. The possible effect of weather (seasons) on the reproductive aspects of this species in the study area is also analyzed. This chapter provides the basic knowledge of reproductive biology that can help improve the current fishing regulation measures such as closures season (with the reproductive cycle) and minimum landing sizes (the mean size of sexual maturity).

In Chapter 5, the seasonal changes of progesterone and testosterone in the gonads of females and males through annual period are quantified. The relationship between the concentrations of steroid hormones (progesterone and testosterone) to events of the reproductive cycle represented by maturity indices (macroscopic and microscopic) in the octopus O. maya also examined. Since the process of sexual maturation and gonad development in octopus has a hormonal control, finally this chapter shows the relationship between hormones (progesterone and testosterone) with the reproductive cycle of O. maya.

Cite as: Avila-Poveda OH (2014) Desarrollo gonádico, ciclo reproductivo y perfiles de progesterona y testosterona gonadal de Octopus maya Voss y Solís-Ramírez, 1966, a lo largo de su historia de vida: neonato, juvenil, subadulto y adulto. Ph.D. thesis. División de estudios de postgrado, Universidad del Mar, Puerto Ángel.

The lack of direct studies on the reproductive cycle of Queen conch Strombus gigas, has made difficult to raise agreed measures of regulation to their cycle; that they allow the rational and sustainable use of this communitarian resource for all Caribbean. This thesis investigates by means of the histological analysis of gonad the reproductive cycle and the spawn season of Strombus gigas at south keys of the Archipelago of San Andres, Providence and Santa Catalina, Colombian insular Caribbean. In addition, appear no more than with major organisms to 20 cm of shell total length, the sexes proportion, the mean length of sexual maturity, and the relation shell total length-lip thickness by a linear model. 346 organisms collected from February of 2003 to January of 2004, were analysed. Biometrics data (Shell total length and lip thickness) and samples from visceral mass (gonad and digestive gland) were taken. The sample were postfixed in Bouin’s fixative, processed with standardized histological methods and stained with Harris’s Haematoxylin and Eosin, regressive stain method. Organisms collected are in a range between 200 and 302 mm shell total length, and 1 to 31 mm lip thickness. The linear model for all the year explained a 22% the data variability (Ln[Gc] = -27,750 + 5.308Ln[Lc]). Females and males proportions do not differ from 1:1. The mean length of sexual maturity in shell total length (L50) was 249 mm to females, 234 mm to males and 241 mm to both sexes. In lip thickness (G50) was 17.5 mm to females, 13 mm to males and 13.5 mm to both sexes. Two qualitative graphical schemes of the gonad cycle were designed, by means of which each gonad development stage was identified and described. The reproductive cycle was defined in 5 gonad development stages: Resting, gametogénesis, mature, emission (spawning and ejaculation) and post-emission. Queen conch is a species with gametogenesis, post-spawn and post-ejaculation all the year. Spawn and ejaculation stages appears synchronous to each other, with a gametogenic strategy of intensity low and duration low, indicating a capacity of slow regeneration. The spawn season it happens in two seasons: (1) March-April and (2) September. The actual prohibition of fishing for the Queen conch Strombus gigas at all Colombian Caribbean, allows to capture organisms at the time of spawn of March to April, observed in this study. it is proposed two situations to temporary fishing ban, derivates from results obtained in this study.

Six organisms of Strombus gigas were collected at 22°22” North and 89°41” West in Alacranes reef, located 135 Kilometers in front to the coasts of the municipality of Progress, in the State of Yucatan, of the Mexican United States, in June of 2001. To know and identify the structural characteristics at cellular and tissue scale to develop a histological atlas of Strombus gigas Linnaeus, 1758. The three males and three females collected presented a length of the shell (of the end of the turn at the end of the sifonal channel) with an average of 228 mm (Standard desviation D.E.=20.4, n=6) and thickness of the lip (in the central part of the lip to 40 mm of the edge of the shell) with an approximated average of 16 mm (D.E.=1.8, n=6). The selected anatomical parts for this study were: Probosis, eye, antenna of the eye, foot, body muscle (females), penis (male), mantle, male gonad, female gonad, digestive gland, style sac, ctenidium, kidney and anal pore. Each animal was removed from its shell and samples were taken of 1 cm3. The samples were fixed for 4 days in Davidson A.F.A. solution, previous to the histological processes. The tissues were washed in 70% ethanol, dehydrated through a graded series ethanols of 70%, 96% and 100%, and embedded in Paraplast paraffin. Sections were cut at six microns of thickness and mounted on albuminized slides. The staining was made with Harris Hematoxylin - yellowish Eosin (HHE2), regressive stain method (modified of Howard y Smith, 1983). All material analized was photographed using a Sony video camera colour of hight resolution join light microscope Carl Zeiss MC-63A.