
Francisco Benitez VillalobosUniversidad del Mar · Instituto de Recursos
Francisco Benitez Villalobos
PhD
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Publications (66)
Environmental temperature is one of the most significant factors influencing the developmental rate and survival of embryos and larvae of many marine animals, including polychaetes. The aim of this study was to experimentally evaluate the effect of temperature increase on the embryonic development and larval survival of Spirobranchus incrassatus an...
Sea urchins play a key role in the marine environment, contributing to maintain a balance in benthic ecosystems. Toxopneustes roseus acts as a regulator of rhodolith beds and is a key species as a bioturbation promoter, while Rhyncholampas pacificus moderates the detritus content of sediment through various mechanisms and contributes to acceleratin...
Trioecy is a sexual system that consists of the co-occurrence of females, males and hermaphrodites in a population and is common in plants; however, in animals it is uncommon and poorly understood. In echinoderms, trioecy had never been recorded until now. Frequencies of females, males, and hermaphrodites were evaluated and gametogenic development...
Scleractinian corals are vulnerable to natural and anthropogenic disturbances and a significant loss of coral cover has been recorded over the last two decades. Sexual reproduction plays an essential role in the maintenance of threatened ecosystems. Corals alter their reproductive patterns in response to changes in local environmental conditions an...
Tropical coastal lagoons are important ecosystems that support high levels of biodiversity and provide several goods and services. Monitoring of benthic biodiversity and detection of harmful or invasive species is crucial, particularly in relation to seasonal and spatial variation of environmental conditions. In this study, eDNA metabarcoding was u...
An organism's maximum gonad investment (MGI) typically indicates its reproductive season and is often measured by the peak of the gonadosomatic index. Since external sexual dimorphism is often not evident, intrinsic sex differences remain unstudied. We analysed the reproductive seasonality of each sex of the broadcast-spawning sea cucumber Holothur...
Spirobranchus es un género de gusanos poliquetos, cuyas especies más grandes son conocidas comúnmente como “pinitos de Navidad marinos”, debido a los llamativos colores y el arreglo en espiral de la corona branquial. Este género pertenece a la familia Serpulidae y existen unas 37 especies válidas a nivel mundial. Los trabajos enfocados en conocer y...
Species of the genus Spirobranchus are sessile polychaetes with an important role in marine ecosystems since they are suspension-feeding invertebrates. However, for most species almost nothing is known about their early and larval development, so we describe the early development of two species of Spirobranchus from the Southern Mexican Pacific. Th...
Reporte de actividades de los levantamientos en campo del sismo del 23 de junio de 2020 (M 7.4) llevado a cabo por profesores y técnicos de la UMAR campus Puerto Ángel.
Field survey done by a local University within the first hours after the earthquake June 23rd, 2020 "La Crucecita, Huatulco". It has a geological and biological focus of the effects...
Lolliguncula diomedeae is captured incidentally in the by-catch of the shrimp trawl fishery, however, there is little information about its life history. Therefore, data on reproductive indicators were collected in this study to evaluate the reproductive biology of L. diomedeae in the Gulf of Tehuantepec. A total of 1525 specimens, 1354 females wit...
Toxopneustes roseus is a species of sea urchin with a wide distribution along the eastern Pacific coast. It belongs to the Toxopneustidae family and, like its members, has well-developed globiferous pedicellariae that exert a variety of pharmacological actions. We identified six volatile non-peptide molecules from its globiferous pedicellariae by u...
Widely distributed species such as Arbacia stellata adjust patterns of their life history according to local conditions. In the present study the reproductive cycle of this species was analysed throughout a sampling year. Gonadal development cycle, sex ratio, actual fecundity and oocyte size distribution were characterized and the relationship of t...
Toxopneustes roseus performs a key role in the eastern tropical Pacific as a strategic herbivore and bioturbation promoter. We evaluated the effect of temperature on the fertilization success, embryonic development and larval survival of T. roseus under laboratory conditions, to understand how the increase in ocean temperature could affect it in a...
Shallow coral reefs worldwide occupy 1.2% of the world’s continental shelf area but support an estimated 35% of all known marine biodiversity. Nevertheless, our knowledge of reef-associated biodiversity in southern Mexican Pacific systems is scarce. Here, we synthesize the knowledge regarding the biodiversity of reef-associated organisms including...
Reproductive studies of an intertidal free-spawning population of Chiton articulatus (Mollusca: Polyplacophora) from Puerto Angel, Oaxaca, Mexico were undertaken during 2011. We used gonad histology and gonadal indices to assess the relative gonad expenditure of the sexes (RGES) and other reproductive traits, accounting for individual and seasonal...
Knowledge of the alpha diversity contributes to the determination of conservation priorities by identifying regions with high species richness and/or a large number of endemic, rare, or endangered species. The present study focused on the evaluation of species richness and composition of the marine mammal community off the coast of Oaxaca. A total...
Knowledge of the alpha diversity contributes to the determination of conservation priorities by identifying regions with high species richness and/or a large number of endemic, rare, or endangered species. The present study focused on the evaluation of species richness and composition of the marine mammal community off the coast of Oaxaca. A total...
Avances en el estudio, manejo y conservación de la diversidad zoológica de México El XXII Congreso Nacional de Zoología en Mazunte, Oaxaca 245 trar consistencia en los comportamientos observados en campo con aquellos reportados por la literatura.
Sexual reproduction of zooxanthellate scleractinian corals in the Eastern Tropical Pacific (ETP) is influenced by the interactive effects of regional and local oceanographic conditions, as well as a variety of other environmental factors. Differences in spatial and temporal gamete development and reproductive patterns of three widespread scleractin...
Las algas constituyen un componente fundamental del ecosistema intermareal rocoso debido a su papel como productores primarios y fuente de alimento para invertebrados herbívoros. La recolecta incidental de macroalgas epibiontes puede vulnerar la biodiversidad y el ecosistema. Bajo el supuesto que la estructura de la comunidad de macroalgas epibiont...
Oaxaca alberga la más alta biodiversidad faunística y florística del sur de México y probablemente de todo el país; sin embargo, los esfuerzos de investigación se han
centrado en la parte terrestre, aunque se percibía que existe mucha información dispersa sobre la biodiversidad marina y costera de Oaxaca...
The brown sea cucumber Isostichopus fuscus (Ludwig, 1875) has been subjected to strong fishing pressure and is currently considered an endangered species by the IUCN Red List of Threatened Species. Spatial and temporal variations in density were analysed and population parameters of I. fuscus were estimated in three localities of the Southern Mexic...
In the intertidal zone availability of substrate is limited and epibiosis frequently occurs. The epibiotic community of a basibiont (substrate organism) at the intertidal rockyshore depends on the basibiont species, season and region. In mollusks, the main basibionts reported belong to the classes Gastropoda, Bivalvia and in lesser degree to Polypl...
The reef-associated echinoderm cryptofauna has received scarce attention notwithstanding its large-scale effects on reef community structures and ecosystem functioning world-wide. In the present study, a spatially hierarchical quantitative sampling protocol was designed to address Pocillopora damicornis-associated echinoderm diversity within and ac...
Octopus maya is the main species caught in Mexico. From September 2007 to June 2008, its sex ratio, reproductive season, frequency of non-vitellogenic and vitellogenic oocytes, reproductive indices, and size and weight at maturity, were evaluated. The monthly sex ratio was significantly different from 1:1. The major reproductive season occurs durin...
Diadema mexicanum is a common inhabitant of the Mexican Pacific coast and a key species for coral reefs dynamics. Several reproductive traits of D. mexicanum throughout one year at La Entrega Bay, Oaxaca (15°44′N), in the Mexican tropical Pacific, were analyzed. Maturity index or microscopic maturity index “MI” was calculated. Annual ratio of males...
The reproductive biology of the massive coral Pavona gigantea has been studied along Mexico’s Pacific coast, but basic aspects such as its relation to local environmental variables and its variation on a mesoscale level have not been addressed. The reproductive cycle of P. gigantea was monitored monthly over a two-year period (2010–2012) at four si...
Variations in progesterone (P4) and testosterone (T) levels in the gonad of Octopus maya from Sisal in Yucatan State, Mexico, were investigated by radioimmunoassays and in relation to four gonad maturation stages (GMS) and to the reproductive cycle, as represented by two maturity indices (microscopic ‘MiMI’ and macroscopic ‘MaMI’). According to the...
Diadema mexicanum, erizo de mar clave en los arrecifes coralinos del Pacífico Tropical Oriental: lo que sabemos y perspectivas futuras (Diadematoida: Diadematidae) Abstract: Diadema mexicanum, a key species of sea urchin in coral reefs of the Eastern Tropical Pacific: state of knowledge and future perspectives. Diadematids are among the most ecolog...
Consecuencias de la mortandad masiva del erizo Diadema mexicanum (Diadematoida: Diadematidae) sobre la comunidad íctica arrecifal en bahía La Entrega, Huatulco, México Abstract: Consequences of a mass mortality event of the sea urchin Diadema mexicanum (Diadematoida: Diadematidae) on the reef icthic community in Bahía La Entrega, Huatulco, Mexico....
Population density, spatial distribution and natural mortality of the sea urchin Toxopneustes roseus (Camarodonta: Toxopneustidae) at three sites in Oaxaca, Mexico. The sea urchin Toxopneustes roseus is widely distributed along the east coast of the tropical Pacific, from Mexico to northern Peru. In our study we evaluated population features of thi...
Diadema mexicanum, a conspicuous inhabitant along the Mexican Pacific coast, is a key species for the dynamics of coral reefs; nevertheless, studies on population dynamics for this species are scarce. Monthly sampling was carried out between April 2008 and March 2009 at Isla Montosa and La Entrega, Oaxaca, Mexico using belt transects. Population de...
The echinoderms of the Southern Mexican Pacific have been studied for three centuries, but discrepancies
in the nomenclature of some species have pervaded through time. The objective of this work is to present the first updated checklist of all valid species and synonyms, and a historical review of the study of the echinoderms of the Southern Mexic...
Coral reefs have key species that control the community structure and composition, and exert influence on the stability and permanence of the reefs. When a key species is lost, there are important effects in the structure and diversity of the coexistent taxa. We analyzed the reef fish community in a period subsequent to the mass mortality event of...
Diadematids are among the most ecologically important sea urchin families. This review presents the state of knowledge of an important member of that family, Diadema mexicanum, in the Tropical Eastern Pacific based on studies carried out mainly in Panama, Costa Rica and Mexico. Density of D. mexicanum is low, fluctuating between 0.008 and 9.5 ind m...
In 2009 there was a report on an event of mass mortality of Diadema mexicanum in La Entrega, Bahías de Huatulco, and partial mortality in adjacent reef communities. In this study we estimated population density of D. mexicanum, as well as natural mortality and spatial distribution in 2 affected localities (San Agustín and Isla Montosa) during a sub...
As a result of literature review, collection visit and field work we compile the systematic list of stony corals (10 species), echinoderms (32 species) and fish (150 species) that inhabit the Parque Nacional Huatulco (PNH). The number of reported species (191) represents an increase similar to 66.9% respect to previous studies. Respect to other Pro...
As a result of literature review, collection visit and field work we compile the systematic list of stony corals
(10 species), echinoderms (32 species) and fishes (150 species) that inhabit the Parque Nacional Huatulco (PNH). The number of reported species (191) represents an increase ~ 66.9% respect to previous studies. Respect to other Protected...
Commercially available radioimmunoassays (RIA) with 125I-labeled hormones were adapted, developed and validated to quantify progesterone and testosterone in gonad extracts of Octopus maya, considered an easily domesticated species with potential in aquaculture. Development of the RIAs was divided into four phases: (1) extraction of progesterone and...
We investigated the current patterns of diversity by country and by class of echinoderms, and analyzed their biogeographical, depth, and habitat or substratum affinities, using the database of the appendix of this book. Traditionally, the area has been divided into five biogeographical Regions and nine Provinces that cover a wide climate range. Cur...
The sea cucumber Holothuria fuscocinerea is among the most common holothurian species widely distributed in the Tropical Eastern Pacific Region and is becoming a potentially important fishery in Mexico. Nevertheless, there are no studies about its reproductive biology. This study analyzed several reproductive traits of H. fuscocinerea based on mont...
The state of Oaxaca in southern Mexico harbors the highest faunistic and floristic biodiversity of the region;
however, to date, research effort has focused on terrestrial flora and fauna. Despite this bias, there is a large amount of dispersed information regarding the coastal and marine biodiversity of Oaxaca. The present study aimed to: 1) updat...
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 pr...
The starfish Pharia pyramidatus is a tropical species of high ecological importance, mainly because of its role as generalist predator. Nevertheless, there are no studies about its reproduction. This study analysed the reproductive biology of P. pyramidatus based on monthly time-series samples from April 2008 to March 2009 at Isla Montosa in the Me...
Mexico is one of the most biodiverse countries on the planet. Knowledge of echinoderm diversity in Mexico started in the XIX Century with Louis Agassiz in 1841. Currently, 643 species of echinoderms are known from Mexico, with Class Ophiuroidea the richest (197 species); Class Asteroidea follows with 185 species, then Class Echinoidea with 119 spec...
I n t r o d u c c i ó n as estrellas de mar (clase Asteroidea) son sin duda los miembros más conocidos de los equi-nodermos, y de los invertebrados marinos en general. Son conocidas también como "el em-blema de los mares". El cuerpo de estos animales, como su nombre lo dice, tiene forma de estrella: cuentan con un disco corporal central del que se...
We analysed the reproductive biology of the asteroid species Styracaster elongatus based on time-series samples from a 5000-m-deep site on the Porcupine Abyssal Plain (N.E. Atlantic). The ratio of males to females, the gonadosomatic index (GI), and pyloric caecum index (PCI) were determined and the results were corroborated by histological examinat...
The reproductive features of two North-Atlantic starfish species, Henricia abyssicola and Styracaster elongatus was determined in time series samples. Specimens of H. abyssicola were collected between
1250 and 1900m in the Porcupine Seabight, and specimens of S. elongatus were collected around 5000m
in the Porcupine Abyssal Plain. The ratio of male...
The sea urchin species Diadema mexicanum is a common inhabitant of the Bahias de Huatulco, an important reef area on the Pacific coast of Mexico (Reyes-Bonilla 2003). Until May 2009 the density of the sea urchins remained relatively constant through time since monitoring began in the 1990s, the highest being found at La Entrega (4–7 ind. m–2) (Beni...
Sea urchins of the genus Diadema play an important role as controlers of algal growth in coral reef and rocky reef communities, but high densities cause bioerosion of the reef framework. Between January 2006 and February 2007 (except April, July and August), population densities and mean test diameter of Diadema mexicanum were determined at Isla Mo...
We present a systematic list of the echinoderms (Asteroidea, Echinoidea) from the coast of Oaxaca in the Southern Mexican Pacific, based on museum specimens of the Colección Nacional de Equinodermos, Instituto de Ciencias del Mar y Limnología, Universidad Nacional Autónoma de México, National Museum of Natural History, Smithsonian Institution, Wash...
We present a systematic list of the echinoderms (Asteroidea, Echinoidea) from the coast of Oaxaca in the Southern Mexican Pacific, based on museum specimens of the Colección Nacional de Equinodermos, Instituto de Ciencias del Mar y Limnología, Universidad Nacional Autónoma de México, National Museum of Natural History, Smithsonian Institution, Wash...
The reproductive biology of the North Atlantic asteroid Henricia abyssicola is determined in time series samples taken from 1250 to 1900 m depth in the Porcupine Seabight (NE Atlantic). The male-female ratio, gonadosomatic index (GI), pyloric caecum index (PCI), fecundity and oocyte size distribution were determined and the results were corroborate...
Eggs of the shallow-water asteroids Asterias rubens and Marthasterias glacialis were
fertilized in vitro and incubated through the early embryonic cleavages until the larval stage. Early
embryos, blastulae, gastrulae, and swimming bipinnaria were subjected to a temperature/pressure
matrix of 5, 10, 15 and 20°C and 1, 50, 100, 150 and 200 atm. Early...
A very important objective of ecological research is to explain the evolution of life histories, more specifically how natural selection modifies reproduction and development in order to generate the patterns that are observed in nature. With few exceptions, the reproductive mechanisms and patterns found in deep-water echinoderms are entirely simil...
The community of echinoderms was characterized in two localities with reefs named La Entrega and Casa Mixteca of the Huatulco Bays, Oaxaca, México. The sampling was carried out from April of 1994 to April of 1995 every two months. For community characterization the Shannon diversity index (H´), Simpson dominance index (l) and Pielou evenness index...