Reproductive biology of dolphinfish, <em>Coryphaena hippurus</em> (Actinopterygii: Coryphaenidae), in Saint Peter and Saint Paul Archipelago, Brazil

In order to elucidate the main aspects related to dolphinfish reproduction around Saint Peter and Saint Paul Archipelago, 862 individuals caught in that area by commercial handline fishing were examined between 2007 and 2011. From those specimens, it was possible to assess the sex in 782 specimens (271 males and 511 females) and the levels of gonadal maturation in 536 of them (175 males and 361 females). The fork length (FL) of the examined specimens varied between 27 and 150 cm. Sex ratio found was 1.0 male: 1.9 females, but the difference was not statistically significant in April (χ2=0.08), August (χ2=0.82) and October (χ2=3.63). However, by size interval, sex ratio was 1.0 male: 1.0 female for FL between 120 and 130 cm. The gonadal index showed the highest values in February for males and in April for females. Most spawning-capable specimens were found in February (males 36.4%) and in May (females 42.2%). The length of size-at-50%-maturity (L50) was estimated at 70.66 cm FL for males and 68.60 cm FL for females. The results suggest that the period of highest reproductive activity occurs between April and June

Biología reproductiva del dorado, Coryphaena hippurus (Actinopterygii: Coryphaenidae), en el Archipiélago de San Pedro y San Pablo, Brasil

In order to elucidate the main aspects related to dolphinfish reproduction around Saint Peter and Saint Paul Archipelago, 862 individuals caught in that area by commercial handline fishing were examined between 2007 and 2011. From those specimens, it was possible to assess the sex in 782 specimens (271 males and 511 females) and the levels of gonadal maturation in 536 of them (175 males and 361 females). The fork length (FL) of the examined specimens varied between 27 and 150 cm. Sex ratio found was 1.0 male: 1.9 females, but the difference was not statistically significant in April (χ2=0.08), August (χ2=0.82) and October (χ2=3.63). However, by size interval, sex ratio was 1.0 male: 1.0 female for FL between 120 and 130 cm. The gonadal index showed the highest values in February for males and in April for females. Most spawning-capable specimens were found in February (males 36.4%) and in May (females 42.2%). The length of size-at-50%-maturity (L50) was estimated at 70.66 cm FL for males and 68.60 cm FL for females. The results suggest that the period of highest reproductive activity occurs between April and June.Con el objetivo de estudiar la reproducción del dorado capturado con línea de mano por la flota pesquera en los alrededores del Archipiélago de San Pedro y San Pablo, entre 2007 y 2011 se examinaron un total de 862 ejemplares de esta especie. Fue posible identificar el sexo de 782 de estos ejemplares (271 machos y 511 hembras), así como los estados de madurez gonadal de 536. La longitud furcal (LF) de los ejemplares examinados varió entre 27 y 150 cm. La proporción de sexos fue de 1 macho por 1.9 hembras, aunque en abril (χ2=0.08), agosto (χ2=0.82) y octubre (χ2=3.63) la proporción de sexos no fue significativamente diferente de 1:1, ni en los ejemplares entre 120 y 130 cm LF. El índice gonadal mostró mayores valores en febrero para machos y en abril para hembras. El mayor porcentaje de individuos maduros se observó en febrero y mayo. La talla de primera madurez sexual (L50) se estimó en 70.66 cm LF para machos y 68.60 cm LF para hembras. Los resultados sugieren que el periodo de mayor intensidad reproductiva se sitúa entre abril y junio

Broad Geographic Distribution of Roundscale Spearfish (Tetrapturus georgii) (Teleostei, Istiophoridae) in the Atlantic Revealed by DNA Analysis: Implications for White Marlin and Roundscale Spearfish Management

The recent validation of the roundscale spearfish (Tetrapturus georgii) within the western North Atlantic has introduced new complexities in the management of the overfished white marlin (Kajikia albida) in this region due to historical and contemporary misidentification between the two morphologically similar species. Compounding the management challenge for white marlin, which is currently assessed as a single Atlantic-wide stock, is an unclear picture of the extent of the roundscale spearfish\u27s overall Atlantic distribution. By using genetic tools (mitochondrial DNA ND4L-ND4 locus sequences) for species identification, we confirm that the roundscale spearfish has a much broader distribution than previously known, including the central North Atlantic and much of the western South Atlantic to at least 28°52′S. This much wider Atlantic distribution of the roundscale spearfish sympatric with its morphologically similar congeners, the white marlin and longbill spearfish (Tetrapturus pfluegeri), raises further management complexities: it increases the geographic scale for species misidentification in catch records that form the basis for stock assessments and uncertainty in currently accepted white marlin biological parameters. Additional vigilance in obtaining accurate species identification by improved fishery onboard observer training and incorporation of genetic tools is recommended for informing management of white marlin, longbill spearfish and roundscale spearfish throughout the Atlantic

Composição das capturas na pesca de atuns e afins em cardumes associados no atlântico oeste equatorial

The present study aims to characterize the catch composition of the fishery for tunas in associated schools in the western equatorial Atlantic. For this purpose, a total of 109 landings on Areia Branca-RN, were observed, from June 2010 to May 2013, as well as on board in nine fishing cruises, from February 2011 to December 2012. The monitored fleet consisted of 9 boats, with an average length overall of 13.4 m. Landings amounted 691,533 kg (6,344.3 +/- 292.7 kg), with a predominance of bigeye and yellowfin tunas, and other bycatch species, such as dolphinfish, blue marlin, skipjack tuna, wahoo, and rainbow runner. Occasionally, other species such as swordfish and triggerfish were also observed.Departamento de Ciências Animais. Universidade Federal Rural do Semi Árido - UFERSA. Av. Francisco Mota, 572 – Bairro Pres. Costa e Silva – CEP: 59.625-900 – Mossoró – RN – BrasiUniversidade Federal de São Paulo – UNIFESP. Av. Dona Ana Costa, 95 - Vila Matias, Santos - SP, CEP: 11060-001Departamento de Pesca e Aquicultura. Universidade Federal Rural de Pernambuco – UFRPE. Av. Dom Manoel de Medeiros s/n. Dois Irmãos. CEP: 52171900 - Recife, PE – BrasilInstituto de Ciências do Mar. Universidade Federal do Ceará – UFC. Av. da Abolição, 3207 – CEP: 60.165-081 – Fortaleza – CE – BrasilUniversidade Federal de São Paulo – UNIFESP. Av. Dona Ana Costa, 95 - Vila Matias, Santos - SP, CEP: 11060-001Web of Scienc

Biología reproductiva del candil gallito Holocentrus adscensionis (Osbeck, 1765) caputrado frente a las costas de Pernunbuco, Brasil

In the present work, specimens of Holocentrus adscensionis, caught off Pernambuco State, northeast Brazil, by small scale artisanal fishing boats, were analyzed with regard to gonad maturation, gonad index, size at first sexual maturity, fecundity, type and time of spawning. Two hundred and three specimens were randomly collected, 102 males and 101 females, resulting in a sex ratio very close to 1:1. Size at first sexual maturity was estimated at 14.6 cm fork length, which is smaller than the most caught size class. Females in final maturation were only recorded from October to March, while the proportion of resting females was the highest in June and July. The seasonal variation of sexual stages, together with the variation of the monthly mean gonad index, with the lowest values for females being recorded from May to July, suggests lower sexual activity for this species during this period of the year, which coincides with winter time. The pattern of ovarian development indicates that spawning is synchronous, with oocytes ripening in more than two groups. It is therefore characterized as a batch spawning. Absolute fecundity ranged from 56274 to 249863 oocytes.En el presente estudio se analizó la madurez gonadal, índice gonadosomático, edad de primera madurez, fecundidad y tipo y periodo de puesta de los especimenes de Holocentrus adscensionis, capturados frente al estado de Pernambuco (noreste de Brasil) por pequeños barcos de la flota artesanal. Se tomó una muestra al azar de 203 especimenes, 102 machos y 101 hembras, obteniéndose una relación de sexos próxima a 1:1. Se estimó la edad de primera madurez a los 14.6 cm de longitud total, menor a la mayoría de tallas capturadas. Hembras en el estadio final de maduración fueron únicamente recolectadas de octubre a marzo, mientras que la más alta proporción de hembras en reposo fue de junio a julio. La variación estacional de estadios sexuales, junto con la variación mensual del índice gonadosomático medio (con los menores valores para las hembras de mayo a julio), sugiere una menor actividad sexual de la especie durante este periodo del año (invierno). El patrón de desarrollo ovárico indica que la puesta está sincronizada con la maduración de los oocitos y tiene lugar en más de dos grupos, siendo pues característica de puestas parciales. La fecundidad absoluta fue de 56274 a 249863 oocitos

Genetic Population Structure of the Recently Validated Billfish, the Roundscale Spearfish, and Its Genetic Diversity and Demographic History Compared to Its Istiophorid Congener, the White Marlin

The recent validation of the roundscale spearfish (Tetrapturus georgii) as a distinct species within the Atlantic, coupled with the facts that it is sympatric with and strongly resembles the overfished white marlin, has clouded management and conservation efforts for both species. It is now realized that historical misidentifications of roundscale spearfish as white marlin have occurred and have therefore complicated management efforts for the latter, since stock assessments have unknowingly been conducted on a species complex. Furthermore, the population status of roundscale spearfish is largely unknown. To aid management of both billfish species, we delineated the genetic population structure of roundscale spearfish in the western Atlantic and assessed its genetic diversity and demographic history relative to the white marlin. We genotyped 203 roundscale spearfish collected from the Northwest (NWA) and Southwest Atlantic (SWA) (n = 144, and n = 59, respectively) at 11 microsatellite loci, and sequenced a 585 bp segment of the mitochondrial control region (mtCR) for a subset (n = 83) of these individuals (NWA n = 42, SWA n = 41). The combined marker sets provided mixed evidence for population differentiation in the western Atlantic. Microsatellite population-level comparisons demonstrated some evidence of genetic differentiation among individuals from the NWA and SWA (FST = 0.004; P = 0.05); however, individual-based, multi-locus cluster analyses grouped these individuals into a single genetic unit. Analysis of mtCR data also showed mixed evidence of differentiation (ÔST = 0.0037, P = 0.284; Snn = 0.618;P = 0.015). Demographic analyses using roundscale spearfish mtCR data and a previously published white marlin mtCR dataset demonstrated substantial historical population growth for both species. Estimates of genetic diversity (Ɵ) appeared to be higher for the white marlin relative to the roundscale spearfish [0.758 (0.532-1.197) and 0.433 (0.295-0.730), respectively], although there was some overlap in confidence intervals. The estimate of lower roundscale spearfish effective female population size, reflected by Ɵ, is consistent with a smaller roundscale population size relative to white marlin as evidenced by fishery observer catch data in the NWA. The mixed signal of population genetic differentiation of roundscale spearfish coupled with a seemingly smaller population size compared to the already depleted white marlin stock, suggests that in the absence of clear contradictory evidence, a two-stock (NWA vs SWA) approach may be the prudent precautionary management strategy for this newly recognized billfish

Global phylogeography of sailfish: deep evolutionary lineages with implications for fisheries management

Since the Miocene profound climatic changes have influenced the biology and ecology of species worldwide, such as their connectivity, genetic population structure, and biogeography. The goal herein is to evaluate the phylogeography of sailfish Istiophorus platypterus between the Atlantic, Indian, and Pacific oceans. Our results evidenced a high genetic diversity and three distinct populations among the ocean basins with limited gene flow among them. In addition, the species is characterized by two deep evolutionary lineages that diverged during the Miocene/Pliocene transition, one of them is circumtropical while the other is restricted to the Atlantic Ocean. These lineages evolved along the successive glacial-interglacial cycles from the Pleistocene and remained isolated from each other in glacial refugium until deglaciation. Assessments of sailfish suggest it may be subject to overfishing and the results herein imply the need to re-evaluate the current stock delimitations and management measures adopted by the Regional Fisheries Management Organizations, especially in the Atlantic and the Indo-Western Pacific oceans to effectively manage the species. In addition, this work highlights that both lineages should at least be treated as two distinct management units in the Atlantic Ocean until their taxonomic status is fully resolved, given their high genetic divergence.Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP)Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP) [2011/23787-0, 2014/26508-3, 2016/09204-6, 2017/17605-3, 2018/20610-1]; Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq)Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPQ) [306054/2006-0, 470762/2013-6]; IRD/Ob7 [2016/1251, 2017/1004]; European UnionEuropean Commission [2016/1251, 2017/1004]; Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior - Brasil (CAPES)Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES) [001]info:eu-repo/semantics/publishedVersio

Diet of the oilfish Ruvettus pretiosus (Perciformes: Gempylidae) in the Saint Peter and Saint Paul archipelago, Brazil

Feeding aspects of the oilfish, Ruvettus pretiosus, were studied based on 360 stomachs of both male and female specimens caught off the Saint Peter and Saint Paul Archipelago. The total length of the specimens ranged from 52.4 cm to 189.0 cm. Of the 360 stomachs examined, 135 presented some food and 225 were empty. Thirty-four taxa were identified, represented by 16 fish, 17 cephalopods and 1 crustacean. The stabilization of the food items richness was attained at 35 food items and 104 stomachs, approximately. A remarkable predation upon the flying fish Cheilopogon cyanopterus was observed around SPSPA, directly related to the main reproductive period of this species in the area. The oilfish's food spectrum shows that the species feeds on a wide vertical range in the water column, catching prey items at the surface or in shallow waters, as well as epi-mesopelagic fish, in addition to mesopelagic cephalopods.<br>Aspectos alimentares do peixe-prego, Ruvettus pretiosus, foram estudados com base nos estômagos de 360 espécimes, de ambos os sexos, capturados nos arredores do Arquipélago de São Pedro e São Paulo. Todos os exemplares foram capturados com linha de mão. O comprimento total dos exemplares variou de 52,4 cm a 189,0 cm. Dos 360 estômagos examinados, 135 apresentaram algum alimento e 225 estavam vazios. Trinta e quatro táxons foram identificados, representados por 16 peixes, 17 cefalópodes e um crustáceo. A estabilização da riqueza dos itens alimentares foi obtida com 35 itens e 104 estômagos. Uma predação notável sobre o peixe-voador Cheilopogon cyanopterus foi observada nas adjacências do ASPSP, diretamente relacionada com o principal período reprodutivo dessa espécie na área. O espectro alimentar do peixe-prego mostra que a espécie se alimenta em uma ampla faixa vertical na coluna d'agua, capturando desde presas de superfície ou águas rasas, a peixes epi-mesopelágicos, além de cefalópodes mesopelágicos