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The silky shark Carcharhinus falciformis is considered one of the least productive pelagic shark species. The estimation of growth and demographic parameters presented here is fundamental to a sound knowledge of population status of the species in the Atlantic Ocean. Data was collected through an onboard observer program of the Brazilian chartered pelagic longline fishing fleet that operates in the Equatorial Southwestern Atlantic. Vertebral analysis produced the von Bertalanffy growth parameters for pooled sexes L∞ = 283.05 cm; k = 0.0987 yr-1 and t0 = -3.47 yr. Males reached sexual maturity at 8.6 yr and females at 9.9 yr. Longevity was estimated at 27.2 yr. Age structure analysis indicated that 80.5% of the catch was composed of juveniles, with recruitment to the fishery from the first year of life (age 1+). These biological parameters are responsible for the species’ low resistance to fishing pressure, and our demographic analysis (Leslie Matrix) shows an annual population decline of 12.7% yr-1 under the current fishing scenario for the period analyzed. Therefore, conservation measures must be enacted to reestablish the population of silky sharks to safe levels for the maintenance of this species in the South Atlantic.

The blue shark (Prionace glauca) is a large predator in marine ecosystems, figuring as the most common and abundant species in oceanic fisheries. For this reason, many studies on this species were conducted throughout its entire distribution range. However, no comparison has been made regarding the variability of the aspects addressed herein. Thus, the present study aims at analyzing the available information on P. glauca. This species constitutes between 85 and 90% of the total elasmobranchs caught by oceanic fisheries with pelagic longlines. Growth parameters reveal that individuals in the Atlantic Ocean show the highest asymptotic lengths when compared to those found in other oceans. Females present an average uterine fecundity of 30 embryos. Although it shows a diverse diet, it is mainly composed of teleost fish and cephalopods. Currently, the main threat to the species is commercial fishing, being listed in Brazil and worldwide, according to IUCN as Near Threatened. Regardless, information on crucial aspects, such as its population dynamics, are still scarce or unreliable for many areas. Despite the number of studies regarding its distribution, abundance, and biology, data for new stock assessments of P. glauca are still needed to improve the species’ management.

The present study describes the fishery and biology of Acoupa Weakfish Cynoscion acoupa, an important fishery resource in South America. We found and analyzed 31 articles and 10 publications about the species. Cynoscion acoupa is an estuarine marine species, which has a feeding habit with preference for fish and crustaceans. Its spawning occurs during two periods of the year and the size at maturity of females is 40 to 50 cm, while males mature earlier, with 38–40 cm. Their growth is considered slow to moderate, with growth coefficient k ranging from 0.13 to 0.28, and the species can reach up to 15 years of age. C. acoupa is target of commercial and recreational fisheries in estuarine and marine coastal environments, mainly in the northern region of South America. The fisheries occur throughout the year, with different fishing gear, being more frequent with gillnets. In addition, fishing is more frequent on juveniles, which may compromise the stock. This species is categorized as of Least Concern by the International Union for Conservation of Nature, although it has a high degree of vulnerability to fishing, which, combined with overexploitation, shows that C. acoupa should be listed as under threat of extinction to some degree. The lack of studies on the species makes it difficult to establish management measures. Therefore, further studies should be prioritized, especially on reproductive biology, growth and fishing exploitation.

International audience; Microchemical analyses were carried out in order to estimate the Strontium:Calcium (Sr:Ca) ratio in the otolith of the white mullet, Mugil curema, in the Pernambuco (at the Santa Cruz channel, Brazil) in order to determine its connectivity between the estuary and ocean. Variation in the otolith Sr:Ca ratio was directly related to salinity, with greater salinity denoting a higher otolith Sr:Ca value. Data on the otolith Sr:Ca ratio demonstrates that the individuals analyzed are born in areas of salinity that are characteristic of the estuary, where they develop until approximately one year of age, at which point they migrate to areas of greater salinity until reaching sexual maturity (3 years of age) in the sea. Spawning occurs in the ocean, after which M. curema individuals may either remain or return to the estuary until the next spawning. Differences in estuarine salinity were found for young of-year individuals and may be related to the season when spawning took place, since M. curema females are found spawning throughout the year. The hypothesis is that higher salinity in the dry season leads to a greater otolith Sr.Ca signature among individuals spawned in this season from birth until one year of life. On the other hand, the lower salinity in the rainy season leads to a lower otolith Sr:Ca signature among individuals spawned in this season. These information are important for the adequate management of the white mullet stock in northeastern Brazil.

Between 2003 and 2005, vertebrae of 151 Xingu River Potamotrygon leopoldi (Potamotrygonidae) (75 males and 76 females) were analysed to derive a growth curve for this species. The disc width (WD ) was significantly different between sexes, with females measuring 149-700 mm WD and males 109-500 mm WD . The average percentage error for vertebrae readings of the whole sample was 2·7%. The marginal increment ratio (RMI ) showed an increasing trend with the highest value in November, decreasing from December on. The majority of vertebrae displaying RMI zero, occurred in September, but the annual periodicity of ring deposition throughout the year was not conclusive. Tetracycline (TCN) injected specimens were held in captivity for 13 months and displayed a fluorescent mark in vertebrae confirming a yearly periodicity of band pair formation with the translucent ring deposited in September-October. The Akaike information criterion (AIC) showed that, among the seven models considered, the best fit was obtained for the von Bertalanffy modified with W0 (where W0 = WD at birth) for both sexes. Growth parameters for females were: W0 = 149 mm; W∞ = 763·06 mm; k = 0·12 year- 1 , whereas for males: W0 = 109 mm; W∞ = 536·4 and k = 0·22 year-1 . Maximal ages were 7·2 years in males and 14·3 years in females. The species shows sexual dimorphism expressed in the growth pattern, size at maturity, longevity and asymptotic sizes. Concern for sustainability is raised due to the construction of the Belo Monte Hydroelectric Power Plant (2015 and 2016) in the State of Para causing changes to the habitat of this species, which is endemic to the Xingu River and two of its tributaries.

The smalltail shark, Carcharhinus porosus, was the most abundant elasmobranch species in fisheries off Brazil’s northern coast (BNC) in the 1980s, but its population has been declining since the 1990s. For this reason, a demographic analysis is necessary to determine the extent of this decline and the fishing effect on the BNC’s population. Therefore, we performed a stochastic demographic analysis of the population in the BNC, and considered its global center of abundance. Smalltail shark specimens (n = 937) were collected with gillnets in Maranhão state, eastern BNC, in the 1980s with sizes ranging between 29.6 and 120.0 cm total length. Most of the individuals (90.6%) caught were juveniles (< 6 years-old), and the mortality and exploitation rates showed that the species was overexploited (92.3% above the fishing mortality corresponding to the population equilibrium threshold). The smalltail shark’s biological characteristics, such as slow growth and low fecundity, demonstrate that it is one of the least resilient species among similar sized coastal sharks in the region. All these factors yielded an annual decrease of 28% in the intrinsic population growth rate, resulting in a population decline of more than 90% in only 10 years, and much higher for the current period. This set of features comprising fishing recruitment occurring upon juveniles, overfishing, and intrinsically low resilience make the population unable to sustain fishing pressure and severely hamper biological recruitment, thus causing this drastic population decline. Furthermore, several local extinctions for this species in the northeastern and southeastern regions of Brazil highlight its concerning conservation scenario. Therefore, since similar fisheries characteristics occur throughout its distribution range, C. porosus fits the criteria E of the IUCN Red List for a critically endangered species and urgent conservation measures are needed to prevent its extinction in the near future.

Several species of lizards are disappearing around the world. Their populations are declining on a global scale and for carrying out conservation actions, it is necessary to identify the real risks of extinction and the threats that affect the species. Alternative methodologies that are commonly applied and also the use of different approaches are important tools to fill gaps concerning various threats and vulnerabilities of the species. The aim of this study was to test the effectiveness of the “Stobutzki sustainability” method in assessing the degree of vulnerability to extinction of lizards with occurrence registered in Pernambuco, Brazil. 41 species were evaluated by using the “Stobutzki sustainability” method, based on scoring and ranking. The analysis was made from a graphical representation of the factors of "Threats" and "Vulnerabilities" of lizards. The great majority of the species (n = 30) has not shown to be vulnerable. Only 11 lizards were not considered sustainable. The lizards Nothobachia ablephara, Cercosaura ocellata, and Procellosaurinus erythrocercus demonstrated a very high degree of vulnerability to extinction. The gymnophtalmidae family was the least sustainable. A total of 16 threats of anthropogenic origin for the populations of lizards in Pernambuco were detected. Half of the species of lizards (n = 21) have a low number of embryos per litter (

The daggernose shark, Isogomphodon oxyrhynchus is endemic to the northern of South America from Trinidad and Tobago to Tubarao bay in Maranhao state (Brazil) where collapsed since the 1990’s, due to several gillnet fisheries for teleost fishes, fisheries targeting sharks, including the daggernose shark, itself, and trawling for shrimp. Based on gillnets with meshes 80– > 200 mm, we analyzed the intrinsic and extrinsic vulnerabilities of the species through different scenarios investigating the species’ resilience. Samples were collected from December 1989 to September 1991, off the coast of Maranhao. Mortalities were M = 0.188 and Z = 0.653 for males and 0.725 in females. Only a scenario without fishing allowed for the population to remain in equilibrium. The survival of young specimens between 1 to 6 years was critical to sustainability according to elasticities that exceeded 70%. The intrinsic rebound ( r z ) of 0.039, demonstrated the species low resilience. An unsustainable exploitation was revealed for different ages at first capture ( t c ) when the maximal yield per recruit ( YPR ) provided F m a x (0.15), below the actual F = 0.47 in 1991 when an exploitation rate E = 0.72 was obtained. Using data collected in 1980/1990 the species was globally categorized in 2006 as critically endangered (CR) similar to assessments in Brazil in 2004. After a three-generation period the species, which did not recover, is now collapsed matching the predicted quasi-extinction condition which claims for urgent and effective conservation measures.

Age and growth of the dolphinfish Coryphaena hippurus caught off north-eastern Brazil were studied by counting growth increments on scales and otoliths. A sample (n = 2338) measuring 7·7-195 cm fork length (LF ) was collected from September 2001 to February 2003. The scales (n = 69) removed from six different regions of the body were examined and those from the caudal region exhibited greater morphological regularity, symmetry and a smaller rate of regeneration. The regression between caudal scale radius (RS ) and LF displayed was linear (LF = 28·334 RS + 9·186; r(2) = 0·754). Otolith micro-increments were counted assuming daily periodicity. Ages estimated from otoliths ranged from 64 to 659 days. The von Bertalanffy growth model was fitted based on the otolith readings generating L∞ = 194·1 cm LF , k = 0·912 year(-1) and t0 = 0·081 years. Species longevity was estimated to be c. 4 years. Ninety-eight per cent of the overall sample was adult specimens well above the age of first maturity in the study area. The large variability between scale length and LF and the failure to ascertain increment deposition periodicity suggest that scales are not appropriate for ageing C. hippurus and analysis of otolith micro-increments is deemed the best structure for ageing this species in the study area.

O objetivo do presente estudo foi estimar os primeiros parí­¢metros de crescimento e mortalidade de Biquara Haemulon plumierii no estado de Pernambuco, Brasil. Os otólitos sagittae foram coletados mensalmente de maio de 2013 a abril de 2014 a partir de desembarques da pesca comercial ao longo da costa de Pernambuco. O total de 333 indiví­­duos medindo 10,5 a 32,2 cm foram capturados. As distribuições de frequência de comprimento foram diferentes entre as áreas. Consequentemente, as relações peso-comprimento foram diferentes entre as áreas, bem como os parí­¢metros de von Bertalanffy. A relação peso-comprimento indicou crescimento alométrico negativo. Portanto, a equação de von Bertalanffy para sexos agrupados foi TLt = 31.1[1-e-0.1 (t +4.57)]. A idade máxima observada foi 21 anos e a mortalidade total foi 0,21 ano-1. As análises conduzidas indicam uma espécie com ciclo de vida longa e crescimento lento. Pequenos peixes recifais de pouca movimentação, como a biquara, são susceptí­­veis ao esforço pesqueiro, fatores ambientais e degradação, que afetam o crescimento e a mortalidade. Portanto, sugerimos uma avaliação do status atual do estoque.

We collected 729 Hypanus guttatus from the northern coast of the state of Rio Grande do Norte (RN), of which 196 were used to estimate age and growth. Ninety-five were male (12.7 to 57.0 cm disc width; WD ) and 101 were female (13.0 to 88.5 cm WD ); females were significantly larger than males. Cross sections of vertebrae showed band-pairs ranging from 0 to > 14 in females and from 0 to 9 in males. New-borns presented an opaque edge at birth in vertebrae without a birthmark. The average percentage of error (APE; %E) for the entire sample provided evidence that ages were repeatable. The mean monthly marginal increment (IM ) indicates annual band-pair formation from August to November. The annual cycle model for one band-pair deposition provided the best fit to data based on the AIC, with peaks between August and October, similar to that found in the IM analysis, suggesting an annual formation pattern. A multi-model approach that included four models based on the observed mean WD at age indicated a modified von Bertalanffy growth model as the best for describing the species growth: W0 (WD at birth) = 14.6 cm for both sexes; females W∞ = 98.61 cm (95% CI = 87.34-114.61 cm); k = 0.112 year-1 (CI = 0.086-0.148 year-1 ); males W∞ = 60.22 cm (CI = 55.66-65.35 cm); k = 0.219 year-1 (CI = 0.185-0.276 year-1 ). The age-at-maturity in males and females is 5 years and 7 years, respectively. The age composition shows that most (84%) specimens were aged 0 to 2 years. The information provided here is essential for analytical assessments of H. guttatus, which is subject to significant fishing pressure mainly on new-borns and juveniles.

Age and growth were analysed on the basis of 372 vertebrae from specimens of the crocodile shark Pseudocarcharias kamoharai (66·0-122·0 cm, total length, LT ) collected in the south-western Atlantic Ocean. Centrum edge analysis suggested the first four months of the year as the period of band completion, leading to acceptance of free-living bands as annual. A pre-birth ring is formed in embryos >31·0 cm LT , whereas the birthmark is deposited in newborns of 46·1 ± 1·1 cm LT (mean ± s.d.). Growth was parameterized using seven models and the AIC was used for selection of the most plausible model. The von Bertalanffy growth model received the greatest support from the data, providing the following growth parameters for combined sexes: L∞ = 129·2 cm, k = 0·137 year(-1) and t0 = -3·9 years. No significant differences were detected in growth by sex, but significant differences in age composition by sex were found in the sample. Overall age ranged from 2 to >13 years in females and from 1 to 8 years in males. Males achieved first maturity at 3·1 years and females at 5·1 years, with pregnancy appearing at 4·8 years. Similar to other lamnoid species, P. kamoharai is relatively fast growing.

Two tagged-and-recaptured tiger sharks Galeocerdo cuvier, measuring 172 and 304 cm total length (L(T) ) and at age 0.75 and 3.50 years, exhibited unmatched growth rates of 118.4 and 55.5 cm year(-1), respectively. The larger fish was nearly mature, indicating that G. cuvier off Brazil could mature considerably earlier than conspecifics from other regions.

From August 1994 to January 1999 and July 2004 to December 2007, 369 blacknose sharks, Carcharhinus acronotus (Poey, 1860), (43.5–146 cm in total length, TL) were collected from gillnets and surveys (longline) carried out on the continental shelf off the state of Pernambuco, Brazil (07°15′45″S and 09°28′18″S). Vertebral sections from 131 males (43.5–124 cm TL) and 146 females (46–146 cm TL) were analyzed. The index of average percentage of error ( IAPE ) estimated from two readings ranged from 1.61 to 4.83 (mean: 6.66%) in the vertebrae of specimens between 0 and 15 years of age. The monthly marginal increment ( MIR ) ratio revealed a tendency toward band pair deposition between autumn and winter, whereas the monthly distribution of growth band pair classes revealed that the first band pair appears on the vertebrae of newborns (ages 0+) about 6 months after birth (by June). This deposition pattern was found in specimens with one, two and three band pairs on the vertebrae (1+ and 2+, respectively), thereby confirming annual band pair completion in winter. Growth parameters were derived using the von Bertalanffy model ( VBGM ), VBGM b (modified by length at birth: L 0 ), the Richards, Gompertz and Schnute models. No significant differences in growth rates were detected between the two sampling periods (1994–1999 and 2004–2008). Models with multiple inflection points, particularly the Richards model, best represented growth for the species, which was evidenced by the lowest Akaike information criterion value. There were no differences in growth between sexes. Growth parameters estimated for both sexes were L ∞ = 129.34 cm (SE = 1.35), k = 0.24 (SE = 0.009) and m = 1.34 with the Richards model. The “average” model was determined by averaging L ∞ between the models with substantial statistical support that were considered the most plausible (Richards and Gompertz). Thus, a consensual L ∞ = 130.69 cm, estimated by multi-model inference, was employed to minimize the effects of sample size and selectivity. Males and females mature at 6 years of age and the largest specimen in the catches was 15 years of age (132 cm TL). Local fishing exploitation using gillnets caught only juveniles, whereas the longlines used for the surveys caught subadult and adult specimens. C. acronotus is a relatively fast-growing species inhabiting shallow coastal waters throughout its lifespan, which is a pattern to be taken into account in the years to come for the management of coastal exploitation targeting valuable teleosts.

Accessible à l'adresse suivante : http://www.int-res.com/abstracts/ab/v7/n3/p199-206/; International audience; Age and growth studies on the white mullet Mugil curema present (Valenciennes, 1836) dissimilarities with regard to the parameters estimated. It is therefore necessary to undertake a growth analysis based on micro- and macrostructures of otoliths from the species in order to reveal the cause of such dissimilarities. Microstructures were validated through otolith marking by balneation in alizarine complexone and demonstrated daily periodicity. Daily microstructures were observed in individuals up to 15.7 cm in fork length and exhibited 5 distinct growth zones. Zones I, II and III (62 d) composed the first macrostructure and Zone IV (223 d) composed the second. It was not possible to see microstructures in Zone V and, beginning with this zone, macrostructures were considered annual, based on the analysis of mean monthly marginal increments. Using daily microstructures and annual macrostructures, the von Bertalanffy function provided the following parameters: L∞ = 34.4 cm, K = 0.365 and t0 = 0.311 yr. The following factors caused the dissimilarities between curves for white mullet: (1) absence of samples for ages 0+ and 1 yr, which caused a high value of mean lengths for these age classes and a diminished K-value; (2) the tendency toward overestimation at the age of 1 yr when estimated from macrostructures; (3) identification of the first 2 macrostructures as annual; and (4) absence of young-of-the-year specimens, causing t0 to be significantly different from 0. These factors lead to the underestimation of the parameters, which makes growth estimates imprecise.

In December 2014, the Brazilian Minister of the Environment released the new national red lists enumerating 2113 plants and 1173 animals threatened with extinction ([ 1 ][1]). Of the 475 aquatic species on the list, 83 are commercially exploited by fisheries, mainly as by-catch. The industrial

Marginal increment ratio (MIR) analyses were conducted as part of age and growth studies on three coastal/semi-oceanic species, the smalltail shark, Carcharhinus porosus, dagger-nose shark, Isogomphodon oxyrhynchus and the night shark C. signatus, and two ubiquitous oceanic species, blue shark, Prionace glauca, and whitetip shark, C. longimanus, collected in equatorial areas off Brazil with the aim of establishing the interspecific temporal nature of vertebral band formation. Monthly variations in marginal bands were analyzed using mean MIR on the entire sample as the standard method for all species. Reasons for the inconclusive results regarding these species are critically appraised with respect to three main sources of bias that are associated with marginal increment analysis (MIA). Bias due to insufficient sample sizes may have hampered the analysis for I. oxyrhynchus and C. longimanus due to movements from shallow waters to seamounts for the former species and to extensive migrations for the latter. Bias due to data collection over too long a period is thought to have influenced monthly mean MIR for C. porosus and P. glauca. For the latter, individuals from different age groups lay down rings at different times, making band deposition inconsistent between individuals. Finally, bias due to births occurring over too long a period was the prevalent cause for confounding MIR values among I. oxyrhynchus and C. signatus species, whose birth period lasts several months and leads to different ages within the same cohort. Other approaches used for MIA in C. signatus and P. glauca led to distinct times of band formation by age-groups when compared to MIR applied on the entire sample. For the daggernose shark, delays in events related to the reproductive cycle from one year to the next were also found to confound MIR. Requirements for the use of MIR implying a band width that displays a sinusoidal cycle when temporally plotted (month or season) were not fulfilled for any of these species. The method has been of little utility for detecting the periodicity of band deposition among sharks from the tropics. This emphasizes the need for supplying information on the temporal periodicity of pair deposition based on other methods.

Between 1992 and 2000, 681 blue sharks, Prionace glauca(173.8–310 cm total length, TL) were collected off northeastern Brazil (Brazilian EEZ). Vertebral sections of 156 males (173.8–310 cm TL) and 80 females (185.5–283 cm TL) were analysed. The index of average percentage error (IAPE) ranged from 0 to 3.1% for 3–12 growth rings (GRs). Mean marginal increment (MI) decreased from November to January without, however, conclusively confirm the annual pattern of deposition. Growth parameters were derived using the von Bertalanffy growth function (VBGF), the Richards function and the Schnute function. VBGF was that which best fit the data. Parameters derived from back-calculated lengths, K = 0.157, L∞ = 352.1 cm and t0 =− 1.01 year, were considered to best describe growth. First maturity sizes of 225 cm for males and 228 cm for females corresponded to 5-GRs individuals. A 310-cm male had 12 GRs which was the highest number in the entire sample. Growth rates of 33.9 cm per GR were estimated from birth to the first band corresponding to 60.2% of size at birth, which is 56.4 cm. Adult males were 90.5% of the entire male sample and, adult females corresponded to 79.6% of the sample of females. The male sample was composed of individuals from 3 to >11 GRs and females were 3 to 10 GRs. Males were larger (with higher number of GRs) and outnumbered females in the overall sample, as commonly occurs in catches worldwide. Despite the hypothesis of differential growth by sex, postulated by several authors, the present study demonstrated that growth curves did not differ significantly, even considering significant vertebral radius (VR)–TL regressions for males and females. Higher growth rates were found in the southern Hemisphere, leading to significant differences in VBGF when compared to other areas. Discards and unreported catches are of great concern for conservation of this important apex predator. © 2003 Elsevier B.V. All rights reserved.

Age and growth of Agassiz's parrotfish Sparisoma frondosum captured off Brazil (Pernambuco) were estimated using sagittal otoliths from 251 specimens. Sex of each specimen was determined and showed that 130 specimens were females (13.1 to 36.8 cm TL) and 121 were males (17.5 to 36.6 cm TL). The otolith marginal increment analysis indicated a single translucent ring formed every year. Parameters of growth curves were derived for the von Bertalanffy (VBGF) and Gompertz models. Based on the Akaike information criterion (AIC), both models were suitable for describing the growth of this species. VBGF parameters were estimated for males L∞ = 39.74 cm TL, K = 0.22, t0 = −1.63 years, females L∞ = 32.38 cm TL, K = 0.44; t0 = −0.23 years; and for the sexes combined L∞ = 33.66 cm TL, K = 0.41, t0 = −0.27 years. The study showed that 55% of individuals were 3 and 4 years of age, with maximal age of 9 years. Mature females (>17.6 cm TL) accounted for 45% of the sample. The age at first maturity for females was 1.6 years. For males the size at first maturity was not determined as immature individuals were not present in the overall sample. Also, primary males (PM) and specimens with gonads undergoing sexual transition were not found. The age structure and growth parameters for S. frondosum are an important contribution to the assessment of the state of exploitation of this species.

Between November 1992 and November 1997, 258 specimens (71.0–250.0 cm-TL) of Carcharhinus longimanus were collected off northeastern Brazil (Brazilian EEZ). Vertebral sections from 110 individuals, 44 males (71.0–235.5 cm), 60 females (81.0–230.0 cm) and six of undetermined sex (120.5–187.2 cm) were analyzed. Mean MIR analysis showed that one band is formed annually starting in August. Male and female growth is similar, back-calculated von Bertalanffy parameters were L ∞ = 325.4 cm, K = 0.075 yr −1 and t 0 = −3.342 yr −1 for both sexes, whereas observed length-at-age parameters were L ∞ = 284.9 cm; K = 0.996 yr −1 , and t 0 = −3.391 yr −1 . Observed length-at-age described growth better than back-calculated lengths. Maturity is reached for both sexes at 180.0–190.0 cm, or 6–7 year-old individuals. The overall sample ranged from a recently born male from the 0 age-class (71.0 cm) to a 17 year-old female (250.0 cm). Growth rates are 25.2 cm yr −1 in the first free-living year, 13.6 cm yr −1 from ages 1 to 4, 9.7 cm yr −1 for adolescents of age 5 and 9.10 cm yr −1 for mature individuals. The size-range of the overall sample is similar to others collected in different locations worldwide. The species follows the K -selected pattern like most elasmobranchs.

Pitaya fruit commercialized in southern Jalisco comes primarily from anthropogenic populations. These populations are associated with archaeological sites dating between 300 B.C. and A.D. 1200. Stand structure and productivity of five anthropogenic stands contrast sharply with that of natural and cultivated stands. Individuals from a natural stand have smaller-diameter trunks and canopies and produce less fruit than anthropogenic stands. Structure and productivity of one stand may correlate with the associated archaeological occupation. Individual productivity is highly correlated with diameter of the canopy. Both men and women participate in the harvest and sale of pitaya fruit earning the same or as much as three times that paid as wage laborers. Conservation of these stands and the associated archaeological sites would require land purchase and protection but the sale of pitaya fruits could sustain the efforts necessary to protect and manage these populations over the long term.

The shortfin mako (Isurus oxyrinchus) is a highly migratory pelagic shark that preferentially inhabits oceanic regions in practically all oceans. The wide distribution range of this species renders it susceptible to coastal and oceanic fishing operations. The International Union for Conservation of Nature (IUCN) and the International Commission for the Conservation of Atlantic Tunas (ICCAT) consider this species to be highly vulnerable, especially due to its biological parameters, which are different from those of other sharks that occupy the same niche (e.g., Prionace glauca). Consequently, considerable declines in abundance have been detected over various parts of its range, most of which are linked to oceanic longline fishing. The species has conflicting life history parameters in studies conducted in the last 30 years, especially with regard to age and growth. The main discrepancies regard the interpretation of the periodicity of the deposition of band pairs (BPs) on vertebrae and the possibility of ontogenetic variations in growth. Shortfin mako sharks (n = 1325) were sampled by onboard observers of the Brazilian chartered pelagic longline fleet based in northeast Brazil from 2005 to 2011. Lengths were 79 to 250 and 73 to 296 cm (fork length, FL) for males and females, respectively, with a statistically significant difference in size between sexes and differences in the proportion of individuals in each size class. The onboard observers collected a subsample of vertebrae (n = 467), only 234 of which were suitable for analyses. Reliability between readings was satisfactory. However, it was not possible to validate periodicity in the formation of age bands in the sample. Thus, the von Bertalanffy growth function was used to calculate growth rates for the species through the interpretation of BPs in different scenarios: one BP per year (s1), two BPs per year (s2) and two BPs per year until five years of life (s3). Growth parameters varied for both females (Linf = 309.7[s3] to 441.6[s1]; k = 0.04[s1] to 0.13[s3]; t0 = -7.08[s1] and -3.27[s3]) and males (Linf = 291.5[s3] to 340.2[s1]; k = 0.04[s1] to 0.13[s3]; t0 = -7.08[s1] and -3.27[s3]). To advance the understanding of the use of habitat, the first analysis of the spatial distribution of the life stages of the shortfin mako sharks caught by commercial longline fishing operations in the South Atlantic was performed. The findings indicate that the portion of the population exploited by the fleets is predominantly juvenile and future actions should take the following issues into account: improvements in the efficiency of data collection procedures, the reestablishment of the onboard observer program, emergency investments in studies that can contribute to a better understanding of habitat use and life history theory.

A sample composed of 4973 specimens of the spotted goatfish, Pseudupeneus maculatus (4.5-29.2 cm fork length) was collected off northeastern Brazil from 1999 to 2002. Sagittae (398) were analyzed for age and growth estimation using both annuli and microincrements. For the first approach, the mean monthly marginal increment ratio analysis suggested that one band is formed annually from May to June. With the microincrements analysis, 15 specimens were reared (3-71 days) for validation of periodicity using oxytetracycline. Fluorescent dyes were observed in 10 specimens (7.5-16.9 cm). After testing, one microincrement was found to form daily. Otolith sections were polished and analyzed using a light microscope (100-1200x magnifications). Individuals larger than 22.6 cm (4 years) showed heavily overlaid increments on the otolith edge, which hampered the counts. There was agreement on the size from counts on an annual and daily basis. The von Bertalanffy function provided the following parameters: L-infinity = 33.23 cm; K = 0.265; t(0) = 0.0883 year. The sample was composed of 0(+) to > 5-year-old specimens. Age at first maturity was 3.6 years (20 cm), whereas the recruitment age for fisheries was 3.9 years. Juveniles represented about half of the catch (48.7%), which may have implications for population equilibrium.

C. porosus is common throughout the year in shallow waters off the Maranhão coast, northern Brazil, where it is the most abundant elasmobranch species. Of 1128 smalltail sharks collected from June 1984 to November 1987 in gill-nets from coastal waters, ~80% were juveniles. Male and female numbers did not differ from a 1:1 ratio. Modal classes were 50.0–60.0 cm (TL) for both sexes. A 120.5 cm female was the largest specimen caught and a 29.4 cm male was the smallest. Age distribution for the whole sample ranged from 0 to >12 years. The length–weight relationship did not differ significantly between the sexes. Diameter of ovarian follicles, presence of eggs/embryos and nidamental gland traits in females point to a major physiological change toward maturity at about 70.0 cm. Vitellogenesis was first observed at 63.0 cm, and the smallest of the six pregnant females was 70.0 cm. There was a significant relationship between the number of embryos and female size. From September to November, ovulation and newborns were observed in catches. Resumo. Carcharhinus porosus é comum ao longo do ano em águas rasas do norte do Brasil onde é a espécie mais abundante entre os elasmobrânquios. De 1128 exemplares coletados em águas costeiras de junho 1984 a novembro 1987 em redes de emalhar ~80% eram jovens. O número de machos e fêmeas não diferiu da razão 1:1. A classe modal foi a de 50.0–60.0 cm para ambos os sexos. Uma fêmea de 120.5 e um macho de 29.4 cm corresponderam ao maior e ao menor exemplar capturado, respectivamente. A distribuição de idades na amostra total variou de 0 a >12 anos. Arelação peso–comprimento não mostrou diferenças significativas entre os sexos. O diâmetro dos ovócitos, presença de embriões/ovos e largura da glândula nidamentária nas fêmeas indica aquisição da maturidade em 70.0 cm. Foi estabelecida uma relação significativa entre o número de embriões e o tamanho das femeas. Entre setembro e novembro ocorre a ovulação e recém nascidos foram observados nas capturas.

Age and growth of the daggernose shark, Isogomphodon oxyrhynchus, from northern Brazil were determined from 105 vertebral sections stained with alizarin red-S representing 46 males, 52 females and 7 specimens of unknown sex (58.4 to 141 cm-TL) and verified with length–frequency analysis of 1135 specimens (632 females and 503 males, 58–160 cm ). Marginal increments did not show significant differences throughout the year, and it was assumed that one band is formed annually. Different tests provided varying results for growth curve comparisons between sexes; the curves were similar, despite biological differences. von Bertalanffy growth parameters estimated from back-calculated mean lengths, observed mean lengths-at-age and length–frequency analysis were of the same magnitude. Parameters generated from observed length-at-age were chosen for describing growth for the species: L• 171.4 cm, k 0.12 year –1 and t0 –2.612 years. The largest female aged from vertebrae was 12 years old, whereas the largest male was aged at 7 years. Neonates, ~42.3 cm, showed one band in the vertebrae, formed at birth, or soon thereafter. Males are mature at 103 cm or 5–6 years and females at 115 cm or 6–7 years. Resumo. A idade e o crescimento do cação quati, Isogomphodon oxyrhynchus, do norte do Brasil foi determinada usando 105 vértebras seccionadas e coradas com alizarina vermelha-S de 46 machos, 52 fêmeas e 7 exemplares de sexo indeterminado (58,4–141 cm-CT). Análise de distribuição de frequência de comprimentos de 1135 indivíduos (632 femeas e 503 machos, 58–160 cm) foi utilizada como método de verificação. Os incrementos marginais não mostraram diferenças significativas ao longo do ano, assumindo-se que uma banda é formada anualmente. Com diferentes testes, usados para comparar curvas de crescimento entre os sexos, obteve-se resultados conflitantes; o crescimento foi considerado idêntico entre os sexos, apesar das diferenças biológicas entre machos e fêmeas. Os parâmetros de von Bertalanffy estimados do retrocálculo, comprimentos médios observados e da análise de comprimentos foram semelhantes, tendo sido escolhidos para descrever o crescimento da espécie: L• 8171,4 cm; k 0,12 year –1 et 0 –2,612 years. Amaior fêmea cuja idade foi estimada pelas vértebras tinha 12 anos enquanto o maior macho tinha 7 anos. Recém-nascidos de 42,3 cm apresentavam uma banda nas vertebras, formada ao nascer, ou logo depois do nascimento. Machos estão maduros em 103 cm ou 5–6 anos e fêmeas em 115 cm ou 6–7 anos.

Age and growth of C. porosus was estimated from seasonally formed marks in vertebrae of 504 specimens (30.0–101.0 cm total length), and from length–frequency data from 1128 individuals (29.4–120.5 cm). Estimated von Bertalanffy growth parameters were: from observed length-at-age, L∞ 125.1 cm, K 0.101 year-1 and t0 –2.89 year; from back-calculated lengths, L∞ 136.4 cm, K 0.077 year-1, t0 –3.27 year; and from length–frequency analysis, L∞ 131.0, K 0.080 and t0 –3.40. Growth did not differ significantly between sexes. Males and females were mature at 71.0 and 70.0 cm, respectively, corresponding to 6 years old. The largest shark aged from vertebrae was a 12-year-old female (101.0 cm). Growth rates calculated from mean observed lengths were 7.0 cm year-1 for the first four years and 4.0 cm year-1 after maturity. Lee’s phenomenon was not apparent. The annulus forms from September to January. Parameters derived from back-calculated lengths were considered to best describe growth. Like most carcharhinids, C. porosus follows the general pattern of K-selected species, exhibiting slow growth, late maturity and low fecundity. Resumo. A idade e o crescimento de C. porosus foram estimados a partir de marcas sazonais em vértebras de 504 indivíduos (30.0–101.0 cm comprimento total) e através de distribuição de freqÜências de comprimentos de 1128 indivíduos (29.4–120.5 cm). Os parâmetros de von Bertalanffy obtidos com comprimentos observados na captura foram: L∞ 125.1 cm, K 0.101 ano –1 e t0 –2.89 anos; com comprimentos retrocalculados: L∞ 136.4 cm, K 0.077 ano-1, t0 –3.27 anos, e da distribuição de freqÜências de comprimentos obteve-se: L∞ 131.0 cm, K 0.080 ano-1 e t0 –3.40. O crescimento não difere entre sexos. Machos e fêmeas são maduras com 71 e 70 cm, respectivamente, correspondendo a idade de 6 anos. O maior espécime cuja idade foi estimada das vértebras tinha 12 anos (101.0 cm). As taxas de crescimento calculadas dos comprimentos médios observados foram 7.0 cm ano-1 para os primeiros quatro anos e 4.0 cm ano-1 após a maturidade. O fenômeno de Lee não ocorreu. O anel se forma entre setembro e janeiro. Os parâmetros obtidos do retroclculo descreveram melhor o crescimento. Como muitos carcharhinideos, C. porosus segue o padrão das espécies da seleção K, exibindo crescimento lento, maturidade tardia e baixa fecundidade.