J. Fernando Márquez-Farías

• PhD.
• Professor (Full) at Facultad de Ciencias del Mar. Universidad Autonoma de Sinaloa.

Information about reproductive parameters, such as age and length at which half the population matures (A50 and L50) of the pelagic thresher (Alopias pelagicus) in the Mexican Pacific, is scarce. To fill this knowledge void, we used maturity data collected from 2015 females and 2030 males captured by pelagic longliners in the Mexican Pacific during...

The pelagic thresher shark (Alopias pelagicus) is considered overexploited; however, information about its biology in the Eastern Pacific is scarce, particularly age estimation and growth modeling. Age was estimated by counting growth bands in the cervical vertebrae. Specimens, ranging in size from 85.00 to 174.90 cm precaudal length (PCL), were co...

Se presenta el análisis de la información disponible sobre la pesquería de tiburón y pez vela en el Pacífico de Costa Rica. El objetivo principal fue evaluar el impacto económico y biológico de estas pesquerías, así como proporcionar información sobre la dinámica espaciotemporal de la flota. Se analizaron los datos de desembarques de tiburón y pez...

Length at life stages of the white shark Carcharodon carcharias is not well known for most of the 9 populations of this species, including in the western North Atlantic (WNA). We analyzed length and maturity data by sex for 87 white sharks with sizes ranging 138-501 cm total length (TL), captured, studied, and released by OCEARCH during 2012-2022,...

Many species of sharks and their relatives show a strong affinity to coral reefs and add high value to reef fisheries and tourism. Despite the economic and ecological importance of these elasmobranchs to reef systems, a recent study found no sharks on almost 20% of surveyed coral reefs around the world. In this chapter, we review relevant informati...

Knowledge of life history and fish reproduction is essential to understand the population dynamics of exploited shark populations. We provide information regarding the length, weight, and sex ratio of Carcharhinus longimanus (oceanic whitetip shark), Galeocerdo cuvier (tiger sharks) and Alopias superciliosus (bigeye thresher sharks) from longline b...

The occurrence of the Filetail catshark Parmaturus xaniurus is rare in the Gulf of California (GC), and its population structure is unknown. We reported its occurrence as bycatch of the Pacific hake fishery in the northern GC. We examined 22 mature females (412-620 mm total length) caught at 263.0-360.2 m depth.

En el presente informe se resume la información obtenida en el reporte “Análisis de la información de la pesquería de grandes pelágicos de interés comercial capturados y desembarcados por las flotas que operan dentro y fuera de la ZEE del Pacífico de Costa Rica”. En términos generales, se muestran las zonas de operación y desembarques de la flota p...

An update of the age and growth for juveniles of the short fin mako shark (I. oxyrinchus) from the Mexican Pacific is presented, based on the analysis of growth band counts from dorsal vertebrae of 198 individuals [110 females, 74–231 cm of total length (TL) and 88 males, 72–231 cm TL) caught during 2008–2018. New available information on vertebral...

The Smooth Butterfly ray Gymnura micrura is caught directly and indirectly in the Gulf of Mexico. In order to know their life history, the age and growth parameters were estimated in 96 females captured from October 2015 to September 2016. The age was assigned following conventional protocols comparing the counts between readers and assuming an ann...

The crocodile shark, Pseudocarcharias kamoharai, is a species of ecological and economic importance in the marine ecosystems of Ecuador. Although it is a fishery resource for local consumption, biological and ecological information and appropriate fishery management are needed to allow its sustainable use. This research aimed to analyze the populat...

La raya mariposa Gymnura micrura es capturada directa e indirectamente en el golfo de México. Para conocer su historia de vida, se determinó la edad y se estimaron los parámetros de crecimiento en 96 hembras capturadas durante octubre 2015 a septiembre 2016. La edad se asignó siguiendo protocolos convencionales comparando los conteos entre lectores...

Life-history studies of species discarded in fisheries are a low priority, particularly those of age and growth estimation. Consequently, almost everything is unknown about such species despite their having been caught as bycatch over the long term. In this study, age estimates were obtained by using the vertebrae of round stingrays (Urobatis halle...

This study aimed to establish the distribution of As, Cd, Cu, Pb, and Zn, in the muscle and liver of the spotted ratfish Hydrolagus colliei from the northern Gulf of California to establish the bioaccumulation background data in this species. The individuals (n = 110) were obtained by bycatch from the Gulf of California hake fisheries, and the meta...

This study aimed to establish the distribution of As, Cd, Pb, Cu, and Zn in the main tissues (muscle, liver, gonads, and gills) of the Pacific hake (Merluccius productus) from the northern Gulf of California to establish baseline bioavailability levels in the northern stock. The results for Pb and Cd were the lowest in the studied tissues (Pb < 0.0...

We report the reproductive strategy of the speckled guitarfish, Pseudobatos glaucostigmus, a poorly studied elasmobranch caught in the south-eastern Gulf of California. Of 2068 specimens collected from the artisanal and industrial shrimp trawl fisheries, 1073 were females and 995 males. The sex ratio of adults and embryos did not deviate significan...

Distribution of arsenic (As) in tissues and gonads of the Indo-Pacific sailfish Istiophorus platypterus and the dolphinfish Coryphaena hippurus from the SE Gulf of California was evaluated. The bioaccumulation patterns of As were the same in the two species. In I. platypterus, As levels (mg kg-1, wet weight) were gonads (7.4 ± 1.1) > liver (3.1 ± 0...

The Straits of Florida comprise an important migratory route for apex predators moving among the Gulf of Mexico, Atlantic Ocean, and Caribbean Sea. Off Cuba’s northwestern coast, various gear types are used by Cuban fishers, including small‐scale pelagic longlines. We report here the results of a 2011–2019 monitoring program for the longline fleet...

The bioaccumulation of arsenic (As) in the muscle, liver, kidneys, and brain of the shark Sphyrna lewini was measured in 40 juvenile specimens from southeast Gulf of California. Additionally, the biomagnification factor was calculated through prey items from stomach contents of the analyzed specimens. The concentrations of As (mg kg⁻¹, wet weight)...

The aim of this study was to use a Bayesian approach to estimate age and growth parameters for the golden cownose ray (Rhinoptera steindachneri) in the southern Gulf of California in Mexico. Age estimates were obtained through analysis of vertebrae of 249 individuals. The von Bertalanffy growth function (VBGF) and Gompertz growth model (GM) were fi...

The purpose of this work was to use the deep-water chimaera Hydrolagus colliei to examine the bioaccumulation and availability of Hg and Se in its deep-water habitat; the Se:Hg molar ratio was calculated to establish baseline information of the species and its associated ecosystem. The organisms were collected from northern Gulf of California. Hg l...

Many shark species show regional structure and seasonal movements, complicating the gathering of life history data needed for fisheries management. Length-at-maturity is a relatively straightforward trait to quantify through the sampling of fisheries landings and is of great value for stock assessment. We report here on the median size at maturity...

The fishery for Pacific hake (Merluccius productus) was established in the northern Gulf of California (NGC) in Mexico in 2000. To describe relevant features of the fishery and biology of Pacific hake, we analyzed 5 years of data from an on board observers program. Using generalized additive models, we standardized catch per unit of effort (CPUE),...

Characterization of essential habitat for sharks is a key requirement for effective conservation of shark populations. In Cuba, shark essential habitat is largely undocumented. Here we present the first study of a shark nursery area in Cuban waters, for the lemon shark. Nursery areas for lemon sharks are typically surrounded by mangroves and contai...

In the present study, we confirm the presence of the Chimaera cubana (Howell Rivero 1936) in Matanzas Bay, north Cuba. Condition of the reproductive tract suggests the specimen was sexually mature female of 82.5 cm total length. Systematic monitoring of these deep-sea fishes is necessary to understand the life history of this primitive fish.

Los Condrictios son un amplio grupo de peces cartilaginosos que engloba a tiburones, rayas, quimeras (Carrier et al. 2012) los cuales se caracterizan por tener un bajo crecimiento poblacional y atributos biológicos que los hacen vulnerables a la sobrepesca provocando la disminución de sus poblaciones (Bonf il, 1995; Musick et al. 2000). En el Golfo...

Biodiversity of marine-coastal ecosystems of Cuba sustains high levels of fishing activity. Due in part to heavy fishing pressure, managers and scientists recognize signs of overfishing for many stocks, intensified by increasing rates of tourism and coastal development. These factors threaten the health of those ecosystems and jeopardize the econom...

La Totoaba Totoaba macdonaldi, es una especie endémica del Alto Golfo de California, la más grande de la familia Sciaenidae que puede alcanzar 2 m de LT y 135 kg. En la década de 1940 se desarrolló una pesquería sobre esta especie dada la demanda de su vejiga natatoria por el mercado asiático. La falta de regulación en las capturas aunado a la redu...

Introducción: En el norte del golfo de California se desarrolla la pesquería industrial de merluza (M. productus). Esta pesquería se desarrolló durante al menos 20 años al amparo de un permiso de pesca comercial de escama marina y recientemente fue integrada a la carta nacional pesquera (D.O.F. 2018). A la fecha se desconocen sus parámetros poblaci...

Records of white sharks (Carcharodon carcharias) sightings or captures from the southern Gulf of California have been poorly documented and anecdotal evidence is limited. Even rarer is the event of a juvenile in subtropical waters. In the present paper, we report the capture of a juvenile female white shark taken in the lower Gulf of California, wh...

In 2007, three rays identified as Rhinoptera brasiliensis based on tooth series counts were captured in the northern Gulf of Mexico, a region far outside their accepted range of the coastal waters of southern Brazil. Genetic analyses confirmed that these individuals were distinct from R. bonasus, the only recognized indigenous rhinopterid in the Gu...

Cadmium, lead, copper, and zinc were analyzed in the dorsal muscle, liver, gonad, and stomach contents of 67 sailfish, Istiophorus platypterus, from the Eastern Pacific. Muscle exhibited the following pattern (μg/g wet weight): Zn (15.05 ± 1.24) > Cu (0.461 ± 0.026) > Cd (0.434 ± 0.099) > Pb (0.025 ± 0.001); liver Zn (119.1 ± 7.6) > Cd (95.1 ± 11.0...

A systematic list of the elasmobranches caught in two fishing trips made during May and June of 2013, on board of a bony-fish trawler ship in the central-east side of the Gulf of California is reported. Fifty nine tows within 45-320 m depth were made. The list recorded 11 species of elasmobranchs (4 sharks and 7 rays) grouped in 8 orders and 9 fami...

Nerocila acuminata (Crustacea: Isopoda: Cymothoidae), ectoparasite of speckled guitarfish Pseudobatos glaucostigma (Elasmobranchii) from southeastern Gulf of California, Mexico The ectoparasite isopod, Nerocila acuminata attaches to the skin of a variety of marine fish species; however , there is not much literature that mentions it infesting elasm...

Distinguishing individual natal origins of highly dispersive species is essential for quantifying the extent of connectivity among spatially separated groups. Variation in the chemical composition of calcified structures has been used to determine natal origins of many organisms but the utility of this approach to sharks and rays has only recently...

Isurus oxyrinchus is a species mostly caught on pelagic longline fisheries. In this study, the occurrence of I. oxyrinchus pregnant female caught to northwest of Cuba is reported; we describe for the firsttime the development stage of the embryos for this region and compare its development phase with previoussurveys carried out in other regions. Th...

The Pacific hagfish (Eptatretus stoutii) and the dark hagfish (E. deani) occur in the North-Eastern Pacific. These two species in the Myxinidae Family, are primitive fish that have a cartilaginous skeleton and lack eyes, jaws, scales and paired fins (Clark & Summers 2007). The Pacific hagfish is the most abundant species, supporting a fishery in th...

Mercury and selenium were assessed in the sailfish, Istiophorus platypterus, from the Eastern Pacific. Sixty-seven individuals were sampled, muscle, liver, kidney, gonads and the prey found in the stomach contents were isolated during fishing 2011-2013 tournaments. Hg exhibited the following pattern (μgg(-1) wet weight): liver (0.57±0.07)>muscle (0...

The industrial shrimp fishery is one of the most important fisheries in Mexico, however, the lack of selectivity of the trawling nets produces the bycatch of until 241 species of fishes, molluscs and crustaceans (López-Martínez et al., 2010), what is translated in to an important ecological impact. The monthly variation of the bycatch: shrimp catch...

Selenium and mercury were evaluated in muscle, liver, kidney, brain, and the stomach contents of juvenile scalloped hammerhead shark Sphyrna lewini. Se:Hg molar ratios were calculated. The average Hg levels in muscle ranged from 0.12 to 1.17 μg/g (wet weight); Hg was <0.39 μg/g in liver and kidneys and <0.19 μg/g in brain. The lowest value of Se wa...

The stomachs of 464 speckled guitarfish Rhinobatos glaucostigma were sampled from the south-eastern Gulf of California (GC) to determine diet composition. Numerical indices and prey-specific index of relative importance (%IPSIR ) were used to determine the feeding strategy of the species. An analysis of similarity (ANOSIM) was used to determine dif...

We determined the Hg content of blood, placenta and umbilical cord of 20 pregnant females of the viviparous Pacific sharpnose shark, Rhizoprionodon longurio and of the livers of the embryos contained in their right and left uterus, aiming to provide information on the amount of this metal offloaded during pregnancy by the mother to the embryos. Hg...

The catch of clam Panopea spp. in Mexico is very recent and there is a growing demand for its commercial exploitation, causing a strong pressure on the resource. The sedentary condition and natural history of these species coupled with the lack of surveillance can lead to overfishing of the stock, so identifying vulnerable stages of their populatio...

Given the high degree of uncertainty on key parameters associated with age and growth of shortfin mako and other pelagic sharks, the Shark Working Group (SHARKWG) of the International Scientific Committee for Tuna and Tuna-like Species in the North Pacific Ocean (ISC), have highlighted the need to take action to standardize protocols for sampling c...

Demographic analysis was used to estimate the trend of population growth of the Rhinobatidae family in the southeastern of Brazil. Different scenarios were evaluated and results showed that without fishing, population can increase to a maximum of 10% per year as observed for Rhinobatos horkelli. In another scenarios considering the presence of fish...

We analyzed the size structure and weight-length relationship of Rhinobatos glaucostigma in the continental shelf of Sinaloa, Mexico. A total of 1129 specimens were examined, of which 491 were female and 638 were males. The sizes for females were 7.4 to 87 cm of total length (LT) with mean of 39.7 cm and males ranged 8.3 and 71.9 cm with mean of 40...

In this study we describe for the first time the reproductive tract morphology and we provide meristic data of the chi-mera Hydrolagus melanophasma from three specimens caught (two females and one male) on the west coast of Baja California. The three specimens were adults. The two females measured 112.6 cm TL and 117 cm TL, and weighed 5555 g and 6...

In this work we compared the cadmium (Cd), copper (Cu), lead (Pb), and zinc (Zn) contents of muscle, liver and placenta of gestating females of the viviparous shark Rhizoprionodon longurio and of muscle, liver and umbilical cord of their respective embryos. The higher values of the essential Cu and Zn were in embryonic or embryo-related tissues (pl...

Size at first maturity was determined for females and males of smooth hammerhead shark, Sphyrna zygaena captured in the Gulf of California during 1995-2000. A total of 1,041 organisms (461 females and 580 males) were analyzed. The size of females ranged 46.0-286.3 cm of total length (TL) whereas the size of males ranged 49.5-278.0 cm TL. The most r...

Size at first maturity was determined for females and males of smooth hammerhead shark, Sphyrna zygaena captured in the Gulf of California during 1995-2000. A total of 1,041 organisms (461 females and 580 males) were analyzed. The size of females ranged 46.0-286.3 cm of total length (TL) whereas the size of males ranged 49.5-278.0 cm TL. The most r...

We analyzed the size structure and weight-length relationship of Rhinobatos glaucostigma in the continental shelf of Sinaloa, Mexico. A total of 1129 specimens were examined, of which 491 were female and 638 were males. The sizes for females were 7.4 to 87 cm of total length (LT) with mean of 39.7 cm and males ranged 8.3 and 71.9 cm with mean of 40...

ABSTRACT. The feeding habits of the sharpnose shark Rhizoprionodon longurio of the SE Gulf of California are described using the stomach contents of 250 specimens (135 males and 115 females) obtained weekly from December 2007 to March 2008 in the two main landing sites of the artisanal fishing fleet of Mazatlan. The mean total length (TL) was 77.7...

The feeding habits of the sharpnose shark Rhizoprionodon longurio of the SE Gulf of California are described using the stomach contents of 250 specimens (135 males and 115 females) obtained weekly from December 2007 to March 2008 in the two main landing sites of the artisanal fishing fleet of Mazatlan. The mean total length (TL) was 77.7 ± 12.8 cm...

The lipid content and fatty acid composition of the liver oil from the ray fish species Urotrygon chilensis, Urobatis halleri, Rhinobatos glaucostigma, Rhinoptera steindachneri and Dasyatis dipterura, rajiforms captured in the State of Sinaloa, México, was examined, and the variation in the fatty acid composition determined by multivariate analysis...

El trabajo presenta un breve resumen cualtitativo de las especies más importantes capturadas en un crucero exploratorio de las aguas profundas del centro del Golfo de California, realizado en mayo de 2013.

INTRODUCCIÓN. Las rayas, tiburones y especies relativas conocidos en general como elasmobranquios engloban aproximadamente mil especies mayoritariamente marinas que habitan un amplio rango de profundidades. Su pesca ha aumentado aceleradamente durante las tres últimas décadas. Mediante estudios previos se sabe que los elasmobranquios son particular...

Intrinsic rebound potential of the endangered (Totoaba macdonaldi) population, endemic to the Gulf of California, México a b s t r a c t The population of totoaba, Totoaba macdonaldi, an endangered, endemic, large sciaenid in the Gulf of California collapsed from over exploitation and habitat degradation. The fishery stopped in 1975 and the current...

En 2008 el Pacífico mexicano contribuyó a la producción de almeja con 88% y el Golfo de México y Mar Caribe con 12%. En el Pacífico destacan Baja California Sur y Sinaloa mientras que Veracruz y Tabasco sobresalen en la zona del Golfo y el Caribe. bcs es el principal productor nacional. La captura de almeja Panopea globosa y P. generosa en México i...

Total mercury (THg) in liver and muscle of three costal sharks from Mexico were evaluated. The highest concentrations of THg in muscle tissue of juveniles were found in Sphyrna lewini (0.82 ± 0.33 mg kg(-1) wet basis). Rhizoprionodon longurio adults had the highest concentrations (0.92 ± 1.03 mg kg(-1)). THg concentrations in liver were low compare...

The feeding ecology and trophic level of the banded guitarfish, Zapteryx exasperata, from the Gulf of California, were assessed using stable isotope analysis (SIA) of carbon and nitrogen in muscle samples, and stomach contents analysis (SCA). Males and females showed similar diet preferences with a high diet overlap (Cλ = 0.99) and similar values o...

The shovelnose guitarfish Rhinobatos productus is the most abundant species in the artisanal ray fishery of the Gulf of California. This ray is captured when it approaches the coast for reproductive purposes and is highly vulnerable to gillnets used in the fishery. Despite the high production of elasmobranchs in the Gulf of California, studies on r...

The shovelnose guitarfish Rhinobatos productus is the most abundant species in the artisanal ray fishery of the Gulf of California. This ray is captured when it approaches the coast for reproductive purposes and is highly vulnerable to gillnets used in the fishery. Despite the high production of elasmobranchs in the Gulf of California, studies on r...

We report on the proportion of maturity stages as a function of size of the Pacific sharpnose shark Rhizoprionodon longurio. Based on the development of internal and external organs, males and females were classified as immature or mature. A logistic model was fitted to develop a maturity curve to estímate the length at which 50% of the individuals...

The white shark is known to inhabit the Gulf of California, but few published records exist for the most frequent localities of captures or sightings of this protected and relatively uncommon shark in Gulf waters. We have compiled and here report 38 records of white shark captures and reliable sightings for the Gulf. Records include individuals cau...

The effect of storage time on the quality of liver oil from two commercial rajiform species (Rhinoptera bonasus and Aetobatus narinari) captured in the Gulf of Mexico (State of Campeche coast line) was evaluated. Oil characterisation was conducted by physical (specific gravity, saponification index and water content) and chemical analyses (fatty ac...

The banded guitarfish, Zapteryx exasperata, is a common species in the artisanal elasmobranch fisheries in the Gulf of California. Fishery-derived specimens were examined to determine critical aspects of the reproductive biology of this poorly known group of rays. Two functional testes and ovaries were found in males and females respectively. Media...

To clarify the taxonomic status of Gymnura crebripunctata and Gymnura marmorata, the extent of morphological and nucleotide variation between these nominal species was examined using multivariate morphological and mitochondrial DNA comparisons of the same characters with congeneric species. Discriminant analysis of 21 morphometric variables from fo...

Lipid composition by class, fatty acids, natural antioxidants (carotenes, tocopherols) and physicochemical characteristics of liver oil from three commercial rays, Rhinoptera bonasus (Chucha), Aetobatus narinari (Pinta) and Dasyatis americana (Bala) from the Gulf of Mexico were analyzed. Liver oil yield for R. bonasus, A. narinari and D. americana...

a b s t r a c t Baseline, species-specific information is largely unavailable for artisanal elasmobranch fisheries, but is essential for the monitoring of exploited populations and the development of effective management plans. Seasonal surveys were conducted during 1998–1999 in Sonora, Mexico to determine the extent and activities of artisanal ela...

IntroductionArtisanal fisheryPelagic longline fisheryGill-net fisheriesShrimp trawl bycatchFisheries interactions and stock assessmentRegulationsConclusions References

The banded guitarfish (Zapteryx exasperata) is a commercially-important species in the Northwest artisanal ray fishery of Mexico. However, very little information about its fisheries characteristics and catch abundance is available. Seasonal sampling was conducted between 1998─2000 and 2004─2005 in five fishery camps in the Gulf of California. Z. e...

The shortfin mako, Isurus oxyrinchus, is a highly migratory species with wide distribution. It is caught directly both as target and bycatch in pelagic fisheries. Detailed knowledge of the biology and nursery grounds of shortfin mako in Eastern Pacific Ocean is limited. Hence, insights on this issue will help understand the structure of the populat...

The blue shark is one of the main species caught in the artisanal fisheries in the northwest coast of Mexico. The age and growth was estimated by counting the growth bands on vertebral centra stained with silver nitrate from 204 sharks. Shark sizes ranged from 81 to 270 cm total length (TL), with a mean of 165 ± 35 cm and a sex ratio of 2:1 between...

The blue shark is one of the main species caught in the artisanal fisheries in the northwest coast of Mexico. The age and growth was estimated by counting the growth bands on vertebral centra stained with silver nitrate from 204 sharks. Shark sizes ranged from 81 to 270 cm total length (TL), with a mean of 165 +/- 35 cm and a sex ratio of 2: 1 betw...

Mexican fisheries landed an annual average of 28,950 metric tons from 1992 to 2002, of which 67% was caught off the Pacific Coast. The most important pelagic species landed were blue shark, threshers, hammerheads, and the silky shark. The major fisheries targeting sharks along the west coast of Mexico are the artisanal fishery, the pelagic longline...

Fish at the top of the food chain bioaccumulate and biomagnify toxic metals including mercury (Hg), at a higher rate than nonpredatory fish. However, although some top predator fish species are important in the human diet, the risks for consumers in Mexico are difficult to evaluate due to the scarce baseline information available. In the present ar...

Guitarfishes are a primary component of artisanal elasmobranch fisheries and are commonly taken as trawl fishery bycatch throughout the Gulf of California. However, little is known of the life history of this species. To address this lack of critical biological information, the reproductive biology of Rhinobatos productus was investigated in the ea...

The golden cownose ray, Rhinoptera steindachneri, was one of the most abundant species landed in artisanal elasmobranch fisheries in the northern Gulf of California (Baja California and Sonora) and Bahía Almejas, Mexico during 1998–1999. In the northern Gulf of California, R. steindachneri was most frequently observed during summer months (11.4% of...

Esta investigación fue posible realizarla en gran parte a través de los fondos proporcionados por la FUNDACIÓN

Description of one of the initial efforts for defining migration routes of pelagic sharks by means of telemetry in the Gulf of California.

The Gulf of California supports the largest ray fishery in Mexico. Sonora is a major ray-fishing state, reporting 56% (live weight) of the Pacific Ocean rays production. Bottom-set gillnets are the principal fishing gear deployed in this artisanal fishery. In the absence of long-term monitoring and complex biological data for fishery stock assessme...

The Pacific sharpnose shark, ( Rhizoprionodon longurio, Jordan and Gilbert, 1882), migrates along the Pacific coast of Mexico. It is captured with gillnets and bottom long lines commonly used in the artisanal fishery of Mazatlan. From a sample of 3 464 individuals, R. longurio was observed to be a viviparous shark of small size, which is born at an...