Breaking Ground in Recurrent or Metastatic Head and Neck Squamous Cell Carcinoma: Novel Therapies Beyond PD-L1 Immunotherapy.

The treatment for recurrent/metastatic (R/M) head and neck squamous cell carcinoma (HNSCC) with immune checkpoint inhibitors (anti-PD1) with or without chemotherapy has led to an improvement in survival. Yet, despite this therapeutic advancement, only 15%-19% of patients remain alive at four years, highlighting the poor survival and unmet need for improved therapies for this patient population. Some of the key evolving novel therapeutics beyond anti-PD1 in R/M HNSCC have included therapeutic vaccine therapies, bispecific antibodies/fusion proteins and multitargeted kinase inhibitors, and antibody-drug conjugates (ADCs). Multiple concurrent investigations of novel therapeutics for patients with R/M HNSCC beyond anti-PD(L)1 inhibition are currently underway with some promising early results. Beyond immune checkpoint inhibition, novel immunotherapeutic strategies including therapeutic vaccines ranging from targeting human papillomavirus-specific epitopes to personalized neoantigen vaccines are ongoing with some early efficacy signals and large, randomized trials. Other novel weapons including bispecific antibodies, fusion proteins, and multitargeted kinase inhibitors leverage multiple concurrent targets and modulation of the tumor microenvironment to harness antitumor immunity and inhibition of protumorigenic signaling pathways with emerging promising results. Finally, as with other solid tumors, ADCs remain a promising therapeutic intervention either alone or in combination with immunotherapy for patients with R/M HNSCC. With early enthusiasm across novel therapies in R/M HNSCC, results of larger randomized trials in R/M HNSCC are eagerly awaited.

Prevalence and Outcomes of COVID-19 among Hematology/Oncology Patients and Providers of a Community-Facing Health System during the B1.1.529 ("Omicron") SARS-CoV-2 Variant Wave.

(1) Background: the SARS-CoV-2 (COVID-19) pandemic continues, and patients actively receiving chemotherapy are known to be at enhanced risk for developing symptomatic disease with poorer outcomes. Our study evaluated the prevalence of COVID-19 among patients and providers of our community-facing county health system during the B1.1.529 ("Omicron") COVID-19 variant wave. (2) Methods: We retrospectively analyzed patients that received care and clinical providers whom worked at the Jackson Memorial Hospital Hematology/Oncology clinic in Miami, Florida, USA, from 1 December 2021 through 30 April 2022. We assessed demographic variables and quality outcomes among patients. (3) Results: 1031 patients and 18 providers were retrospectively analyzed. 90 patients tested positive for COVID-19 (8.73%), while 6 providers tested positive (33.3%) (p = 0.038). There were 4 (10.3%) COVID-19-related deaths (and another outside our study timeframe) and 39 non-COVID-19-related deaths (89.7%) in the patient population (p = 0.77). COVID-19 accounted for 4.44% of our clinic's total mortality, and delayed care in 64.4% of patients. (4) Conclusions: The prevalence of COVID-19 positivity in our patient cohort mirrored local, state, and national trends, however a statistically significant greater proportion of our providers tested positive. Almost two-thirds of patients experienced a cancer treatment delay, significantly impacting oncologic care.

Update 2021: Management of Small Cell Lung Cancer.

BACKGROUND: Accounting for 14% of lung cancer, small cell lung cancer (SCLC) is a highly aggressive neuroendocrine malignancy with rapid proliferation, early spread, and poor survival. AIM AND METHODS: We provide an overview of recent advances regarding SCLC pathogenesis, subtypes, and treatment development through literature review of key trials. RESULTS: There are no validated biomarkers or approved targeted treatments for this overly heterogeneous disease, but recent analyses have identified some promising targets and four major subtypes which may carry unique therapeutic vulnerabilities in SCLC. Treatment wise, only a third of patients present with limited stage SCLC, which can be managed with a combined modality approach with curative intent (usually chemo-radiotherapy, but in some eligible patients, surgery followed by systemic treatment). For advanced or extensive stage SCLC, combined chemotherapy (platinum-etoposide) and immunotherapy (atezolizumab or durvalumab during and after chemotherapy) has become the new standard front-line treatment, with modest improvement in overall survival. In the second-line setting, for disease relapse ≤ 6 months, topotecan, lurbinectedin, and clinical trials are reasonable treatment options; for disease relapse > 6 months, original regimen, topotecan or lurbinectedin can be considered. Moreover, Trilaciclib, a CD4/CD6 inhibitor, was recently FDA-approved to decrease the incidence of chemotherapy-related myelosuppression in SCLC patients. CONCLUSIONS: While modest improvements in survival have been made especially in the metastatic setting with chemo-immunotherapy, further research in understanding the biology of SCLC is warranted to develop biomarker-driven therapeutic strategies and combinational approaches for this aggressive disease.

Interspecific synchrony is related to body-length similarity in a fish community under prolonged drought conditions.

Interspecific synchrony and trait-based differences between species are likely to be related to each other. Therefore, we investigated interspecific synchrony patterns in a fish community under prolonged drought conditions, using a trait-based approach. We hypothesized that trait-similarity would predict interspecific synchrony among fish populations. We also expected that a general synchronous pattern for the whole community would be high during a severe drought context, indicating low stability. The study was conducted in a semi-arid reservoir between 2010 and 2017, which encompassed a five-year period of severe drought. We considered species differences in body length, gonadosomatic index, relative condition factor, and trophic level and found that interspecific synchrony was negatively related to species differences in body length. This result can be related to species requirements in terms of habitats and food resources. We also found a significant level of community-wide synchrony, with important implications for community stability during periods of prolonged drought. In conclusion, our results indicated a strong effect of environmental filtering in fish population dynamics over time. We highlight the importance of a trait-based approach to shed light on understanding ecological processes driving population dynamics.

Targeting of CD40 and PD-L1 Pathways Inhibits Progression of Oral Premalignant Lesions in a Carcinogen-induced Model of Oral Squamous Cell Carcinoma.

We have previously demonstrated that PD-1 blockade decreased the incidence of high-grade dysplasia in a carcinogen-induced murine model of oral squamous cell carcinoma (OSCC). It remains unknown, however, whether there are additional factors involved in escape from immune surveillance that could serve as additional targets for immunoprevention. We performed this study to further characterize the immune landscape of oral premalignant lesions (OPL) and determine the impact of targeting of the PD-1, CTLA-4, CD40, or OX40 pathways on the development of OPLs and oral carcinomas in the 4-nitroquinoline 1-oxide model. The immune pathways were targeted using mAbs or, in the case of the PD-1/PD-L1 pathway, using PD-L1-knockout (PD-L1ko) mice. After intervention, tongues and cervical lymph nodes were harvested and analyzed for malignant progression and modulation of the immune milieu, respectively. Targeting of CD40 with an agonist mAb was the most effective treatment to reduce transition of OPLs to OSCC; PD-1 alone or in combination with CTLA-4 inhibition, or PD-L1ko, also reduced progression of OPLs to OSCC, albeit to a lesser extent. Distinct patterns of immune system modulation were observed for the CD40 agonists compared with blockade of the PD-1/PD-L1 axis with or without CTLA-4 blockade; CD40 agonist generated a lasting expansion of experienced/memory cytotoxic T lymphocytes and M1 macrophages, whereas PD-1/CTLA-4 blockade resulted in a pronounced depletion of regulatory T cells among other changes. These data suggest that distinct approaches may be used for targeting different steps in the development of OSCC, and that CD40 agonists merit investigation as potential immunoprevention agents in this setting. PREVENTION RELEVANCE: PD-1/PD-L1 pathway blockade, as well as activation of the CD40 pathway, were able to prevent OPL progression into invasive OSCC in a murine model. A distinct pattern of immune modulation was observed when either the CD40 or the PD-1/PD-L1 pathways were targeted.

Role of Mitochondria in Cancer Immune Evasion and Potential Therapeutic Approaches.

The role of mitochondria in cancer formation and progression has been studied extensively, but much remains to be understood about this complex relationship. Mitochondria regulate many processes that are known to be altered in cancer cells, from metabolism to oxidative stress to apoptosis. Here, we review the evolving understanding of the role of mitochondria in cancer cells, and highlight key evidence supporting the role of mitochondria in cancer immune evasion and the effects of mitochondria-targeted antitumor therapy. Also considered is how knowledge of the role of mitochondria in cancer can be used to design and improve cancer therapies, particularly immunotherapy and radiation therapy. We further offer critical insights into the mechanisms by which mitochondria influence tumor immune responses, not only in cancer cells but also in immune cells. Given the central role of mitochondria in the complex interactions between cancer and the immune system, high priority should be placed on developing rational strategies to address mitochondria as potential targets in future preclinical and clinical studies. We believe that targeting mitochondria may provide additional opportunities in the development of novel antitumor therapeutics.

An evaluation of the economic viability of environmental offsets in the saltworks industry / Uma avaliação da viabilidade econômica de compensações ambientais na indústria salineira

ABSTRACT: The extraction of sea salt depends on the occupation of large areas at the estuary banks, many of them inserted in Permanent Preservation Areas (PPAs). Thus, the objective was to evaluate the economic viability of Environmental Offsets (EO) as an alternative to the unoccupied PPAs in the saltworks. In order to do so, 27 solar saltworks installed in the region of the Brazilian White Coast were evaluated for the occupation of PPAs - measured using images from satellite, georeferenced, vectored with corresponding PPA bands generated - and estimated to EO (Impact Degree x Sum of the investments necessary to implement the project) and Economic Impact (Net Present Value, with long-term interest rate of 7%) of vacating PPAs. It was considered that EO was feasible whenever the costs resulting from it were lower than the economic impact caused by the vacancy of the PPAs. The PPAs were tthe productive area of ​​the saltworksthat occupied 13.70% of PPAs. For all the evaluated enterprises the value corresponding to EO was lower than the Economic Impact resulting from the vacancy of the PPAs. Thus, EO is an economically viable and more attractive alternative to the eviction of PPAs by the saltworks industry and may also provide environmental gains due to the financing of conservation units in the areas of influence of the enterprises. However, there is a need to improve the methodology used to estimate the EO, since a maximum limit is set, the environmental impacts caused by the projects are underestimated.

RESUMO: A extração de sal marinho depende da ocupação de grandes áreas às margens de estuários, muitas delas inseridas em Áreas de Preservação Permanente (APPs). Assim, objetivou-se avaliar a viabilidade econômica da Compensação Ambiental (CA) como alternativa à desocupação de APP pelas salinas. Para tanto, 27 salinas instaladas na região da Costa Branca brasileira foram avaliadas quanto à ocupação de APPs - mensuradas por meio de imagens de satélites, georreferenciadas, vetorizadas com a geração de bandas de APP - e estimados a CA (Grau de Impacto x Somatório dos investimentos necessários para implantação do empreendimento) e o Impacto Econômico (Valor Presente Líquido, com taxa de juros de longo prazo de 7%) da desocupação das APPs. A CA foi considerada viável quando seus custos resultantes foram menor do que o impacto econômico causado pela desocupação das APPs. A área produtiva média das salinas ocupa 13,70% de APP. Para todos os empreendimentos avaliados, o valor correspondente a CA foi menor que o Impacto Econômico resultante da desocupação das APP. Assim, a CA é uma alternativa economicamente viável e mais atrativa frente à desocupação das APP pela indústria salineira, podendo ainda propiciar ganhos ambientais em decorrência do financiamento de Unidades de Conservação nas áreas de influência dos empreendimentos. Evidencia-se, contudo, a necessidade do aprimoramento da metodologia usada para estimar a CA, já que fixado um limite máximo, os impactos ambientais provocados pelos empreendimentos são subestimados.

Freshwater fish richness baseline from the São Francisco Interbasin Water Transfer Project in the Brazilian Semiarid

Among Neotropical freshwater ecoregions, the Mid-Northeastern Caatinga (MNCE) is a fish knowledge gap. Its temporary drainages are receptors of the São Francisco interbasin water transfer project (SFR-IWT) in the Brazilian semiarid. We provide a comprehensive baseline of fish richness of the five SFR-IWT basins. Species richness, shared, endemic, threatened and non-native species were obtained using sampling, ichthyologic collections, literature and online repositories (306 localities). In total 121, species were recorded, 111 of them native, and 16 (14.41%) listed for all basins. Higher richness of native species (78, 70.27%) was recorded in the São Francisco lower-middle stretch (SFRE), including 23 endemic, 61 (54.95%) in MNCE basins (13 endemic), and 28 (25.23%) shared between both ecoregions. In the MNCE, 50 species were recorded in Jaguaribe (JAG), 39 in Piranhas-Açu, 36 in Paraíba do Norte, and 32 in Apodi-Mossoró (APO). The number of species shared between the SFRE and each receptor basin varied from 24 (23.08%, JAG) to 20 (22.22%, APO). JAG contains 81.97% of the receptor basins' species. Its higher richness and endemism deserve special attention regarding the ongoing hydrological changes. This study will help detect possible modifications in the ichthyofauna of the main MNCE drainages.(AU)

Dentre as ecorregiões dulcícolas neotropicais, a Nordeste Médio-Oriental (MNCE) é uma lacuna de conhecimento sobre peixes. Suas drenagens temporárias são receptoras do projeto de transposição do São Francisco (SFR-IWT) no semiárido brasileiro. Fornecemos uma linha de base abrangente da riqueza de peixes das cinco bacias do SFR-IWT. Riqueza de espécies, espécies compartilhadas, endêmicas, ameaçadas e não-nativas foram obtidas através de amostragem, coleções ictiológicas, literatura e repositórios online (306 localidades). No total, foram registradas 121 espécies, 111 nativas e 16 (14,41%) listadas para todas as bacias. A maior riqueza de espécies nativas (78, 70,27%) foi registrada no trecho sub-médio do São Francisco (SFRE), incluindo 23 endêmicas e 61 (54,95%) nas bacias da MNCE (13 endêmicas), e 28 (25,23 %) compartilhadas entre ambas ecorregiões. Na MNCE, foram registradas 50 espécies na Jaguaribe (JAG), 39 na Piranhas-Açu, 36 na Paraíba do Norte e 32 na Apodi-Mossoró (APO). O número de espécies compartilhadas entre SFRE e cada bacia receptora variou de 24 (23,08%, JAG) a 20 (22,22%, APO). JAG contém 81,97% das espécies das bacias receptoras. Sua maior riqueza e endemismo merecem atenção especial em relação às mudanças hidrológicas em curso. Este estudo ajudará a detectar possíveis modificações na ictiofauna das principais drenagens da MNCE.(AU)

Olhar etnográfico e intervenção social na produção e uso de imagens: entrevista com José Roberto Novaes (Beto Novaes) / Ethnographic approach and social intervention in the production and use of images: interview with José Roberto Novaes (Beto Novaes)

Resumo Beto Novaes é professor aposentado do Instituto de Economia da Universidade Federal do Rio de Janeiro, onde coordena o projeto Educação através das Imagens. Desenvolve desde meados dos anos 1970 pesquisas e atividades de extensão baseadas no uso de imagens sobre trabalho e trabalhadores, em sua maioria no setor rural. Imagens são o meio que utiliza para aproximar a pesquisa e o saber acadêmico da sociedade, descontruindo hierarquia de saberes na qual o conhecimento acadêmico seria superior. Suas produções têm origem em demandas sociais para tratar de problemas com pouca visibilidade social, dentre eles: a exploração do trabalho e as migrações no mundo rural; trabalho infantil e das mulheres; resistências dos trabalhadores; agroecologia e enfrentamento aos agrotóxicos. Seu olhar etnográfico faz contraponto ao exercício da dominação por meio das narrativas dos trabalhadores, "dando voz para quem não têm voz" e, desenhando caminhos de enfrentamento e mudança da realidade. Seus documentários são ensinamentos da arte da etnografia e da prática de intervenção, não apenas para participar da mudança da realidade social, mas também para influenciar a práxis acadêmica. Seus filmes são também peças artísticas onde a beleza convive com a sensibilidade, generosidade, engajamento e esperança.

Abstract Beto Novaes is a retired professor of the Institute of Economics of the Federal University of Rio de Janeiro, where he coordinates the 'Education through Images' project. Since the mid-seventies, he has undertaken research and extension activities based on the use of images about work and workers, mostly in the rural sector. Images are the means used to bring research and academic knowledge closer to society, disrupting the hierarchy of knowledge in which academic knowledge is normally considered superior. His productions arise from social demands to deal with problems of little visibility such as: the exploitation of labor and migrations in the rural domain, child and female labor, workers' resistance, agroecology and confrontation with pesticides use. Through his ethnographic approach, he acts against the exercise of domination through workers' narratives, 'giving voice to those who have no voice', and designing ways of confronting with and changing reality. His documentaries express teachings in the art of ethnography and in the practice of intervention, not only with a view to change social reality, but also to influence academic praxis. His films are also artistic pieces where beauty coexists with sensitivity, generosity, commitment and hope.

Effects of a Supraseasonal Drought on the Ecological Attributes of Plagioscion squamosissimus (Heckel, 1840) (Pisces, Sciaenidae) in a Brazilian Reservoir.

The aim of this study was to evaluate the effect of a supraseasonal drought on the ecological attributes of Plagioscion squamosissimus. The fish were caught quarterly from February 2010 to November 2014 using gill nets in the reservoir of Santa Cruz, Rio Grande do Norte, Brazil. The abundance of the species was evaluated with the catch per unit effort (CPUE) metric and then correlated with the accumulated rainfall and water volume of the reservoir. The diet of the fish was evaluated using the feeding index (IAi). The proportional similarity index (PS i ) was used to evaluate the variation in the niches of the fish. The body condition was inferred through the relative condition factor, and its variation was assessed with ANOVA. A reduction in the abundance of the species that were positively correlated with the reservoir water volume was observed. The diet of the fish comprised shrimp, gastropods, fish, insects, shrimp larvae, and vegetable matter, with shrimp being the major component. PS i showed the occurrence of individual specialization during November 2013 and November 2014. The relative condition factor was not correlated with a reduction in the water volume of the reservoir. The supraseasonal drought did not affect the relative condition factor, diet, and the trophic niche, but it did affect the species abundance.

Population structure and reproduction of a migratory fish Leporinus piau (Characiformes: Anostomidae) in a semiarid tropical reservoir, Brazil / Estructura poblacional y reproducción del pez migratorio Leporinus piau (Characiformes: Anostomidae) en una represa tropical semiárida, Brasil

Abstract:Migratory fishes have been seriously impacted by the building of reservoirs and because of the negative effects of these projects such as the interruption of migratory routes, reduction or elimination of spawning/ feeding areas, and initial development can influence the population structure the migratory fishes, resulting in reduction in abundance. Leporinus piau is migratory fish widely distributed in the watersheds of the Brazilian semiarid and it is of importance for artisanal and sport fishing. The goal of the study was to evaluate the population structure and reproductive dynamics of the migratory species Leporinus piau in the Pau dos Ferros Reservoir, which is located in the semiarid region of Brazil. The CPUE, length structure, length-weight relation-ship, length at first maturity, sex ratio, gonad development and IGS were analyzed. Collections were performed quarterly between February 2011 and November 2012 using gillnets. The captured fish were counted; the standard length (cm) and total weight (g) were measured, and dissected to determine the sex and gonad maturity stage. The rainfall and reservoir water levels were recorded, and their correlations with the reproductive period and CPUE were analyzed. A total 549 individuals were captured. The average CPUE varied between 0.0259 individuals/m2*h (May/2011) and 0.0008 individuals/m2*h (August/2012), and significant differences were observed; however, significant correlations were not observed between rainfall and reservoir levels. The standard length varied between 5.9 cm and 20.7 cm, and the weight varied between 4.16 g and 271.5 g. A histogram analysis revealed that the 5-10 cm standard length class was the most abundant for juveniles and that the 10-15 cm class was the most abundant for adult females and males. The weight-length relationship was best fit by the equation log10Wt = -1.57711 + 3.00707 Log10 Ls, and the species presented isometric growth. The estimated length at first maturity was 12.76 cm. A total of 148 males and 82 females were collected (1.81:1, M:F), and these values were significantly different. The highest GSI was observed in February 2011 for both females (10.69) and males (5.72), and the GSI was significantly and positively correlated with rainfall. We concluded that the L. piau population is established in the reservoir and found that its reproduction period occurred during the rainy season between February and May. Rev. Biol. Trop. 64 (4): 1369-1381. Epub 2016 December 01.

Resumen:Los peces migratorios se han visto gravemente afectados por la construcción de embalses y los efectos negativos de estos proyectos, tales como la interrupción de rutas migratorias, reducción o eliminación de desove / áreas de alimentación. El desarrollo inicial puede influir en la estructura de la población de los peces migratorios, lo que resulta en la reducción en la abundancia de los mismos. El Leporinus piau es un pez migratorio que se encuentra ampliamente distribuido en las cuencas del semiárido brasileño y es de importancia para la pesca deportiva y artesanal. El objetivo del estudio fue evaluar la estructura de la población y la dinámica de reproducción de la especie migratoria Leporinus piau en el embalse Pau dos Ferros, región semiárida de Brasil. La relación estructura de tallas y talla-peso de la CPU la talla de la primera la madurez, proporción de sexos, el desarrollo gonadal y el IGS se analizaron. Con redes de enmalle se llevaron a cabo recolecciones trimestralmente entre febrero 2011 y noviembre 2012. Se contaron los peces capturados; se midieron la longitud estándar (cm) y peso total (g), y se disectaron para determinar el estadio del sexo y la madurez de las gónadas. Los niveles de agua de lluvia y los embalses se registraron y se analizaron sus correlaciones con el período reproductivo y la CPUE. Un total de 549 individuos fueron capturados. La CPUE promedio varió entre 0.0259 individuos/m2 * h (mayo/ 2011) y 0.0008 individuos/m2 * h (Agosto/2012), y se observaron diferencias significativas; sin embargo, ninguna correlación significativa se observo entre los niveles de lluvia y el nivel de la represa. La longitud estándar varió entre 5.9 y 20.7 cm, y el peso entre 4.16 y 271.5 g. Un análisis de histogramas, reveló que la clase estándar de 5-10 cm de longitud fue la más abundante de los jóvenes y que la clase 10-15 cm fue la más abundante de las hembras y machos adultos. La relación peso-talla se ajusta más adecuadamente a la ecuación log10Wt = -1.57711 + 3.00707 Log10 Ls, donde la especie presenta un crecimiento isométrico. La medida estimada de la primera madurez fue 12.76 cm. Se recogieron un total de 148 machos y 82 hembras (1.81: 1, M: F), y estos valores fueron significativamente diferentes. El más alto GSI se observó en febrero 2011, tanto para las mujeres (10.69) como para hombres (5.72), y el GSI fue significativa y positivamente correlacionado con la precipitación. Se llegó a la conclusión de que la población L. piau está establecida en la represa y encontramos que su periodo de reproducción se produjo durante la época de lluvias entre febrero y mayo.

Prognostic factors, predictive markers and cancer biology: the triad for successful oral cancer chemoprevention.

Oral squamous cell carcinomas represent a significant cancer burden worldwide. Unfortunately, chemoprevention strategies investigated to date have failed to produce an agent considered standard of care to prevent oral cancers. Nonetheless, recent advances in clinical trial design may streamline drug development in this setting. In this manuscript, we review some of these improvements, including risk prediction tools based on molecular markers that help select patients most suitable for chemoprevention. We also discuss the opportunities that novel preclinical models and modern molecular profiling techniques will bring to the prevention field in the near future, and propose a clinical trials framework that incorporates molecular prognostic factors, predictive markers and cancer biology as a roadmap to improve chemoprevention strategies for oral cancers.

Population structure and reproduction of a migratory fish Leporinus piau (Characiformes: Anostomidae) in a semiarid tropical reservoir, Brazil.

Migratory fishes have been seriously impacted by the building of reservoirs and because of the negative effects of these projects such as the interruption of migratory routes, reduction or elimination of spawning/feeding areas, and initial development can influence the population structure the migratory fishes, resulting in reduction in abundance. Leporinus piau is migratory fish widely distributed in the watersheds of the Brazilian semiarid and it is of importance for artisanal and sport fishing. The goal of the study was to evaluate the population structure and reproductive dynamics of the migratory species Leporinus piau in the Pau dos Ferros Reservoir, which is located in the semiarid region of Brazil. The CPUE, length structure, length-weight relationship, length at first maturity, sex ratio, gonad development and IGS were analyzed. Collections were performed quarterly between February 2011 and November 2012 using gillnets. The captured fish were counted; the standard length (cm) and total weight (g) were measured, and dissected to determine the sex and gonad maturity stage. The rainfall and reservoir water levels were recorded, and their correlations with the reproductive period and CPUE were analyzed. A total 549 individuals were captured. The average CPUE varied between 0.0259 individuals/m2*h (May/2011) and 0.0008 individuals/m2*h (August/2012), and significant differences were observed; however, significant correlations were not observed between rainfall and reservoir levels. The standard length varied between 5.9 cm and 20.7 cm, and the weight varied between 4.16 g and 271.5 g. A histogram analysis revealed that the 5-10 cm standard length class was the most abundant for juveniles and that the 10-15 cm class was the most abundant for adult females and males. The weight-length relationship was best fit by the equation log10Wt = -1.57711 + 3.00707 Log10 Ls, and the species presented isometric growth. The estimated length at first maturity was 12.76 cm. A total of 148 males and 82 females were collected (1.81:1, M:F), and these values were significantly different. The highest GSI was observed in February 2011 for both females (10.69) and males (5.72), and the GSI was significantly and positively correlated with rainfall. We concluded that the L. piau population is established in the reservoir and found that its reproduction period occurred during the rainy season between February and May.

Population structure and reproductive period of two introduced fish species in a Brazilian semiarid region reservoir.

The Amazonian fish species Plagioscion squamosissimus (Sciaenidae) and Cichla monoculus Cichlidae), have been widely introduced into different reservoirs in Brazil, and have caused many negative mpacts on local fish fauna. The aim of this study was to evaluate the population structure (abundance, length structure, length-weight relationship, sex ratio, and length at first maturity) and the reprodutive period of these wo species in the Santa Cruz Reservoir (built in 2002), located in the Brazilian semiarid region, for their adequate management and local species conservation policies. Specimens were collected quarterly in eight sites from February 2010 to November 2013 using gillnets (12 to 70 mm mesh between adjacent knots). The specimens captured were counted and the following biometric and biological data were analysed: standard length, total weight, and reproductive data, such as, sex, weight and gonadal maturity stage. The species abundances were estimated by CPUE and expressed as the number of individuals per gill net area x gill net exposition time (m2 x h); length frequency histograms were built with intervals of 5 cm. The length-weight parameters were estimated with a linear regression after a logarithmic transformation of the data. With the reproductive data we estimated sex ratio, reproduction period and length at first maturity (L50). We captured a total of 1,071 specimens of P. squamosissimus and 156 specimens of C. monoculus. Both species showed higher abundances in 2010, 0.004306 m2 x h and 0.00022 m2 x h, respectively, but this parameter decreased from 2010 to 2013. Standard length ranged between 6.4 and 46.2 cm for P. squamosissimus (20.025.0 cm was the most frequent class), and 7.0 and 38.7 cm for C. monocidus (10.0-15.0 cm was the most frequent class). The length-weight relationships were described by the following equations: log10Wt = -1.8349+3.0899log10Lp and R2= 0.9795 for P. squamosissimus, and log10 Wt = -1.7944+3.0885log10Lp and Wt = 0.0160 and R2 = 0.9929 for C. monoculus; both species exhibited positive allometric growth. The sex ratio for both species differed from 1:1, with a predominance of females for P. squamosissimus and males for C. monoculus. The Lp50 was estimated to be 15.90 cm for P. squamosissimus and 15.65 cm for C. monoculus, and the reproductive data indicated that both species reproduced throughout the year. We concluded that although the population of both species reduced their abundance over the study period, P. squamosissimus and C. monoculus are established and structured populations in the Santa Cruz Reservoir with individuals growing satisfactorily and reproducing in all seasons, without a well-defined reproductive peak. We suggest that the managers may allow the artisanal and/or sport fisheries of these species.

Population structure and reproductive period of two introduced fish species in a Brazilian semiarid region reservoir / Estructura poblacional y período reproductivo de dos especies introducidas de peces en una represa de una región semiárida brasileña

The Amazonian fish species Plagioscion squamosissimus(Sciaenidae) and Cichla monoculus(Cichlidae), have been widely introduced into different reservoirs in Brazil, and have caused many negative impacts on local fish fauna. The aim of this study was to evaluate the population structure (abundance, length structure, length-weight relationship, sex ratio, and length at first maturity) and the reprodutive period of these two species in the Santa Cruz Reservoir (built in 2002), located in the Brazilian semiarid region, for their adequate management and local species conservation policies. Specimens were collected quarterly in eight sites from February 2010 to November 2013 using gillnets (12 to 70 mm mesh between adjacent knots). The specimens captured were counted and the following biometric and biological data were analysed: standard length, total weight, and reproductive data, such as, sex, weight and gonadal maturity stage. The species abundances were estimated by CPUE and expressed as the number of individuals per gill net area x gill net exposition time (m2 x h); length frequency histograms were built with intervals of 5 cm. The length-weight parameters were estimated with a linear regression after a logarithmic transformation of the data. With the reproductive data we estimated sex ratio, reproduction period and length at first maturity (L50). We captured a total of 1 071 specimens of P. squamosissimusand 156 specimens of C. monoculus.Both species showed higher abundances in 2010, 0.004306 m2 x h and 0.00022 m2 x h, respectively, but this parameter decreased from 2010 to 2013. Standard length ranged between 6.4 and 46.2 cm for P. squamosissimus(20.025.0 cm was the most frequent class), and 7.0 and 38.7 cm for C. monoculus(10.0-15.0 cm was the most frequent class). The length-weight relationships were described by the following equations: log10Wt = -1.8349+3.0899log10Lp and R2 = 0.9795 for P. squamosissimus,and log10Wt = -1.7944+3.0885log10Lp and Wt = 0.0160 and R2 = 0.9929 for C. monoculus;both species exhibited positive allometric growth. The sex ratio for both species differed from 1:1, with a predominance of females for P. squamosissimusand males for C. monoculus.The Lp50 was estimated to be 15.90 cm for P. squa-mosissimusand 15.65 cm for C. monoculus,and the reproductive data indicated that both species reproduced throughout the year. We concluded that although the population of both species reduced their abundance over the study period, P. squamosissimusand C. monoculusare established and structured populations in the Santa Cruz Reservoir with individuals growing satisfactorily and reproducing in all seasons, without a well-defined reproductive peak. We suggest that the managers may allow the artisanal and/or sport fisheries of these species.

Las especies de peces amazónicos Plagioscion squamosissimus(Sciaenidae) y Cichla monoculus(Cichlidae), se han introducido ampliamente en diferentes embalses en Brasil, y han causado muchos impactos negativos sobre la fauna de peces locales. El objetivo de este estudio fue evaluar la estructura poblacio-nal (abundancia, estructura de tallas, relación talla-peso, proporción de sexos, y talla de primera madurez) y el período reproductivo de estas dos especies en la represa Santa Cruz, (construida en el 2002), situada en la región semiárida de Brasil. Las muestras se recogieron trimestralmente en ocho sitios de febrero 2010 a noviembre 2013 mediante redes de pesca (12 a 70 mm). Los ejemplares capturados se contaron y se analizaron los siguientes datos bio-métricos y biológicos: longitud estándar, peso total, y datos reproductivos, tales como: sexo, peso y estado de madurez gonadal. Capturamos un total de 1 071 ejemplares de P. squamosis-simusy 156 de C. monoculus.Ambas especies mostraron mayor abundancia en el 2010, 0.004306 m2 x h y 0.00022 m2 x h, respectivamente, pero este parámetro disminuyó de 2010 a 2013. La longitud estándar osciló entre 6.4 y 46.2 cm para P squamosissimusy 7.0 y 38.7 cm para C. monoculus.Las relaciones talla-peso fueron descritas por las siguientes ecuaciones: log10Wt = -1.8349 + 3.0899log10Lp y R2 = 0.9795 para P squamosissimusy log10Wt = -1.7944 + 3.0885log10Lp y Wt = 0.0160 yR2 = 0.9929 para C. monoculus;ambas especies mostraron un crecimiento alométrico positivo. La proporción de sexos para ambas especies difirió de 1:1, con un predominio de hembras en P. squamosissimusy machos en C. monoculus.El LP50 se estimó en 15.90 cm para P. squamosissimusy 15.65 cm para C. monoculus,los datos de reproducción indicaron que ambas especies se reproducen durante todo el año. Llegamos a la conclusión de que aunque la población de ambas especies redujo su abundancia durante el período de estudio, P. squamosissimusy C. monoculusestán ...

Analysis of artisanal fisheries in two reservoirs of the upper Parana River basin (Southeastern Brazil)

We compared the artisanal fisheries, in terms of catch strategies, productivity, and gross per capita income, at two reservoirs: the Barra Bonita (an eutrophic reservoir with some introduced species), and the Jurumirim (an oligotrophic reservoir, with no introduced species). Published data and structured interviews with fishers were used to evaluate fishing activity, fish biomass, and the financial performance of the fisheries. In the Barra Bonita Reservoir we analysed data from 745 fishing trips, from which 86,691.9 kg of fish were landed, with a mean CPUE of 62.4 kg/fisher-1 day-1. The main type of fish caught was tilapia (71,513.5 kg; CPUE of 51.5 kg/fisher-1 day-1), which constituted 82.5% of the biomass caught. In the Jurumirim Reservoir, we analysed data from 2,401 fishing trips, from which 25,093.6 kg of fish were landed, with a mean CPUE of 10.4 kg/fisher-1 day-1. The main type of fish caught was "traíra" (6,158.6 kg; CPUE of 2.6 kg/fisher-1 day-1), which constituted 24.5% of the biomass caught. Ordination analysis (PCA) indicated that there was a difference in composition between the fishing reservoirs and ANCOVA showed that there was a significant difference in fish production between the reservoirs. A Student's t-test showed that fishers in the Barra Bonita Reservoir had a significantly higher gross per capita income than those from the Jurumirim Reservoir. Although the Barra Bonita Reservoir has a higher fish production and the fishers earn a higher gross per capita income, we recommend the Jurumirim Reservoir as a model for artisanal fishery management because fishing activity in this reservoir is viable in the long term and such a model would promote conservation and sustainability. This contrasts with the Barra Bonita Reservoir, in which the fishery is not viable in the long term, due to environmental problems caused by artificial eutrophication and the introduction of alien species. It is also noted that in many countries, management of fisheries based on exotic species has not been viable in the long term.

Nós comparamos a pesca artesanal, em termo de estratégia de captura, produtividade e renda per capita bruta em dois reservatórios: Barra Bonita (reservatório eutrófico e com espécies introduzidas) e Jurumirim (reservatório oligotrófico e sem espécies introduzidas). Dados publicados e entrevistas estruturadas mensais com os pescadores sobre a atividade de pesca, quilo pescado e rendimento financeiro, foram usados para as análises. No reservatório de Barra Bonita foram analisados dados de 745 viagens pesqueiras, que desembarcaram 86.691,9 kg de pescado, com CPUE de 62,4 kg/pescador-1 dia-1. O principal pescado foi a tilápia (71.513,5 kg, CPUE de 51,5 kg/pescador-1dia-1) que representou 82,5% da biomassa pescada. No reservatório de Jurumirim analisamos dados de 2.401 viagens pesqueiras, que desembarcaram 25.093,6, como CPUE de 10, kg/ pescador-1 dia-1. O principal pescado foi a traíra (6.158,6 kg, CPUE de 2,6 kg pescador-1 dia-1), que representou 24,5% da biomassa pescada. Uma análise de ordenação (PCA) indicou diferença na composição pesqueira entre os reservatórios e uma ANCOVA indicou diferença na produção pesqueira entre os reservatórios. Teste t de Student foi significativo e os pescadores do reservatório de Barra Bonita tiveram maior renda per capita bruta. Embora o reservatório de Barra Bonita tenha tido maior produção pesqueira e os pescadores maior renda, recomendamos o reservatório de Jurumirim como modelo para gestão de pesca artesanal nos reservatório, pois a atividade mostrou ser viável em longo prazo bem como ecologicamente correto. Isto contrasta como o reservatório de Barra Bonita, em que a pesca não é viável em longo prazo, devido a problemas ambientais provocados pela eutrofização artificial e pela introdução de espécie. Observou-se que em muitos países, o manejo da pesca com espécies exóticas, não tem sido viável em longo prazo.

Reproduction, food dynamics and exploitation level of Oreochromis niloticus (Perciformes: Cichlidae) from artisanal fisheries in Barra Bonita Reservoir, Brazil

Nile tilapia (Oreochromis niloticus), which is exotic to South America, is the most common species caught in artisanal fisheries at the Barra Bonita Reservoir, Southeastern Brazil. This species is of great socioeconomic importance for the region and keeps active a population of about 500 fishers. In the present study we assess reproduction, food dynamics and level of exploitation of O. niloticus, caught by artisanal fisheries in the Barra Bonita Reservoir. Specimens were collected monthly, from July 2004-June 2005, and a total of 1 715 specimens were analyzed. Each specimen was examined to obtain biological and biometric data: standard length (cm), total weight (g), reproductive data (sex and stage of maturation), and stomach contents (empty, partly full, and full). We also estimated the sex ratio (by macroscopic observation of gonads), reproductive period (by ovarian development and seasonal average of gonadosomatic index in females), and feeding habits (by stomach contents). The possible relationship between abiotic factors and the reproductive period was statistically verified using Spearman’s Rank Correlation. The FiSAT (ELEFAN I) package was used to assess growth parameters, mortality rates and to infer exploitation rate from standard length frequencies. The O. niloticus population had a sex ratio of 1.3:1 (M:F). Results indicated that ripe females were captured throughout the year, with a higher frequency during the winter-2004 (with a frequency of 59%, at a mean temperature of 20.5°C), and in spring-2004 (with a frequency of 60.5% at a mean temperature of 21.18°C). The GSI mean values obtained by season were: winter-2004: 1.71; spring-2004: 1.72; summer-2005: 0.80, and autumn-2005: 1.19. The Spearman correlation indicated positive values with respect to pH, dissolved oxygen, electric conductivity, transparency and chlorophyll a, and negative values with respect to temperature, accumulated rainfall and altimetric benchmark. The main food items were phytoplankton and periphytic algae, observed in 99.6% of the analyzed stomachs. The estimated growth and mortality parameters were: L∞=33.60cm, k=0.63/year, longevity= 4.76years, Z=2.81/ year, M=1.20/year and F=1.61/year. The weight-length relationship was Ln Wt=-2.8532+2.8835 Ln Lp. The estimated yield per recruit values were as follows: E=0.570, Emax=0.776, E0.1=0.604 and E0.5=0.349. These results indicate that a well established population of O. niloticus is present at Barra Bonita Reservoir; with an active reproduction throughout the year, more intense during winter and spring, and that O. niloticus is a phytoplanktophagus species. There were no indications that this species is being overfished, we therefore recommend that, due to its exotic condition, no restrictions need to be taken on its fishing activities. Rev. Biol. Trop. 60 (2): 721-734. Epub 2012 June 01.

La exótica tilapia del Nilo (Oreochromis niloticus) es la especie mayormente capturada en la pesquería artesanal del embalse de Barra Bonita, sudeste de Brasil, de gran importancia socioeconómica para la región y para una población de unos 500 pescadores. El estudio analizo: la reproducción, la dinámica alimentaria y la explotación de O. niloticus, la cual fue capturada en la pesquería del embalse de Barra Bonita. Asimismo, se tomaron muestras mensuales y se analizo un total de 1 715 animales desde julio-2004 a junio-2005. De cada espécimen, se obtuvieron los siguientes datos biológicos y biométricos: longitud estándar (cm), peso total (g), datos reproductivos (sexo y estadio de maduración), contenido estomacal (vacio, parcialmente lleno y lleno). Estos datos fueron utilizados para estimar la proporción de sexo (a través de la observación macroscópica de las gónadas), el periodo reproductivo (a través de la distribución de la frecuencia de los estadios macroscópicos del desarrollo de los ovarios), y la media de la proporción del índice gonadosomático IGS de hembras, así como los hábitos alimentarios (a través de la observación del contenido estomacal). Para verificar las posibles relaciones entre los factores abióticos y el periodo reproductivo fue aplicada la correlación de Spearman. El software FiSAT (ELEFAN I) fue utilizado para evaluar los parámetros de crecimiento, tasa de mortalidad e inferir el grado de explotación, en donde se usaron los datos de frecuencia de longitud estándar. La población de O. niloticus presento una proporción de sexo 1.3:1 (M:H). Los resultados indicaron que hembras fueron muestreadas durante todo el ano, pero ha sido más frecuente en el invierno-2004-59.0% (temperatura media=20.05°C) y primavera-2004-60.5% (temperatura media=21.18°C). Los valores medios del IGS fueron: invierno-2004=1.71, primavera- 2004=1.72, verano-2005=0.80 y otoño-2005=1.19. La correlación de Spearman fue positiva para pH, oxigeno disuelto, conductividad eléctrica, transparencia y clorofila a, y negativo para temperatura, pluviosidad acumulada y variación del nivel del agua en el embalse. Los principales ítems de alimentación fueron fitoplancton y algas perifiticas observadas en 99.6% de los estómagos analizados. Los parámetros estimados del crecimiento y mortalidad fueron los siguientes: L∞=33.60cm, k=0.63/año, longevidad= 4.76 años, Z= 2.81/año, M=1.20/año y F=1.61año. La relación peso-longitud fue Ln Wt=-2.8532+2.8835 Ln Lp. Los valores de producción por reclutamiento estimado fueron=0.570, Emax=0.776, E0.1=0.604 y E0.5=0.349. Estos resultados indican que la población de O. niloticus está bien establecida en el embalse de Barra Bonita. Además, su reproducción ocurre durante todo el ano, pero es más intensa en el invierno y primavera; su dieta tiene como base el fitoplancton. Los resultados indican que no está ocurriendo sobrepesca de O. niloticus, por tanto, recomendamos que, debido a su naturaleza exótica, no se tomen restricciones a la hora de su pesca.

Reproduction, food dynamics and exploitation level of Oreochromis niloticus (Perciformes: Cichlidae) from artisanal fisheries in Barra Bonita Reservoir, Brazil.

Nile tilapia (Oreochromis niloticus), which is exotic to South America, is the most common species caught in artisanal fisheries at the Barra Bonita Reservoir, Southeastern Brazil. This species is of great socioeconomic importance for the region and keeps active a population of about 500 fishers. In the present study we assess reproduction, food dynamics and level of exploitation of O. niloticus, caught by artisanal fisheries in the Barra Bonita Reservoir. Specimens were collected monthly, from July 2004-June 2005, and a total of 1 715 specimens were analyzed. Each specimen was examined to obtain biological and biometric data: standard length (cm), total weight (g), reproductive data (sex and stage of maturation), and stomach contents (empty, partly full, and full). We also estimated the sex ratio (by macroscopic observation of gonads), reproductive period (by ovarian development and seasonal average of gonadosomatic index in females), and feeding habits (by stomach contents). The possible relationship between abiotic factors and the reproductive period was statistically verified using Spearman's Rank Correlation. The FiSAT (ELEFAN I) package was used to assess growth parameters, mortality rates and to infer exploitation rate from standard length frequencies. The O. niloticus population had a sex ratio of 1.3:1 (M:F). Results indicated that ripe females were captured throughout the year, with a higher frequency during the winter-2004 (with a frequency of 59%, at a mean temperature of 20.5 degreeC), and in spring-2004 (with a frequency of 60.5% at a mean temperature of 21.18 degreeC). The GSI mean values obtained by season were: winter-2004: 1.71; spring-2004: 1.72; summer-2005: 0.80, and autumn-2005: 1.19. The Spearman correlation indicated positive values with respect to pH, dissolved oxygen, electric conductivity, transparency and chlorophyll a, and negative values with respect to temperature, accumulated rainfall and altimetric benchmark. The main food items were phytoplankton and periphytic algae, observed in 99.6% of the analyzed stomachs. The estimated growth and mortality parameters were: Linfinity=33.60cm, k=0.63/year, longevity= 4.76years, Z=2.81/ year, M=1.20/year and F=1.61/year. The weight-length relationship was Ln Wt=-2.8532+2.8835 Ln Lp. The estimated yield per recruit values were as follows: E=0.570, Emax=0.776, E0.1=0.604 and E0.5=0.349. These results indicate that a well established population of O. niloticus is present at Barra Bonita Reservoir; with an active reproduction throughout the year, more intense during winter and spring, and that O. niloticus is a phyto-planktophagus species. There were no indications that this species is being overfished, we therefore recommend that, due to its exotic condition, no restrictions need to be taken on its fishing activities.

Population structure and stock assessment of Hoplias malabaricus (Characiformes: Erythrinidae) caught by artisanal fishermen in river-reservoir transition area in Brazil.

Hoplias malabaricus is a viable economic alternative for artisanal fishermen who used to live on the banks of rivers that now are dammed in Brazil. In order to preserve the species' natural stock, the main objectives of this study were to obtain bio-ecological information on this species reproduction, feeding dynamics and the description of the extent of its exploitation in river-reservoir transition area in Brazil. This way, from January to December 2005, different fishery catches were made with gill nets by artisanal fishermen, and a total of 426 individual H. malabaricus were obtained and sampled. From each specimen, the following biometric and biological data were analyzed: standard length, total weight, stomach contents, reproductive data such as sex, weight and gonadal maturation stage; with these data we estimated sex ratio, reproduction period and feeding habits. To assess growth parameters and infer on the degree of exploitation, the standard length frequency data were analysed using the FISAT (ELEFAN I) computer program. Data revealed a sex ratio of 0.8:1 (M:F), that reproduction occurs all year around, being more intense during spring and summer; it also showed that H. malabaricus is piscivorous. The growth parameters and mortality were estimated at: L(infinity) = 35.18 cm, k = 0.32 year, longevity = 9.3 years, Z = 1.25 years, M = 0.63 year and F = 0.62 year. The weight-length relationship was: In Wt = -3.1663+2.7456 In Lp. The yield-per-recruit analysis produced the following values: E = 0.496, E(max) = 0.916, E0.1 = 0.701 and E0.5 = 0.378. Overall, our data suggest that the stock of H. malabaricus is not yet overfished in the studied area.

Population structure and stock assessment of Hoplias malabaricus (Characiformes: Erythrinidae) caught by artisanal fishermen in river-reservoir transition area in Brazil

Hoplias malabaricus is a viable economic alternative for artisanal fishermen who used to live on the banks of rivers that now are dammed in Brazil. In order to preserve the species’ natural stock, the main objectives of this study were to obtain bio-ecological information on this species reproduction, feeding dynamics and the description of the extent of its exploitation in river-reservoir transition area in Brazil. This way, from January to December 2005, different fishery catches were made with gill nets by artisanal fishermen, and a total of 426 individual H. malabaricus were obtained and sampled. From each specimen, the following biometric and biological data were analyzed: standard length, total weight, stomach contents, reproductive data such as sex, weight and gonadal maturation stage; with these data we estimated sex ratio, reproduction period and feeding habits. To assess growth parameters and infer on the degree of exploitation, the standard length frequency data were analysed using the FISAT (ELEFAN I) computer program. Data revealed a sex ratio of 0.8:1 (M:F), that reproduction occurs all year around, being more intense during spring and summer; it also showed that H. malabaricus is piscivorous. The growth parameters and mortality were estimated at: L∞=35.18cm, k=0.32 year, longevity=9.3 years, Z=1.25 years, M=0.63 year and F=0.62 year. The weight-length relationship was: ln Wt=-3.1663+2.7456 ln Lp. The yield-per-recruit analysis produced the following values: E=0.496, Emax=0.916, E0.1=0.701 and E0.5=0.378. Overall, our data suggest that the stock of H. malabaricus is not yet overfished in the studied area. Rev. Biol. Trop. 59 (1): 71-83. Epub 2011 March 01.

Hoplias malabaricus representa una alternativa económica viable para los pescadores artesanales que viven a la orilla de ríos que actualmente cuentan con represas en Brasil. El objeto del presente estudio fue evaluar la dinámica de la reproducción, alimentación, crecimiento y nivel de explotación de la especie nativa Hoplias malabaricus, capturada por pescadores artesanales en la zona de transición entre el río Paranapanema y el Embalse de Jurumirim. En 2005, los especimenes de H. malabaricus se obtuvieron utilizando redes agalleras de forma mensual y se registraron las siguientes características y datos biológicos de cada uno: longitud estándar, peso corporal, sexo, estadio reproductivo, peso de las gónadas y contenido estomacal. Estos datos fueron utilizados para estimar la proporción sexual, el período reproductivo y los hábitos alimenticios. Para evaluar los parámetros de crecimiento y el grado de explotación, los datos de frecuencia de la longitud estándar fueron analizados utilizando el software FISAT a través de la rutina ELEFAN I. Según los resultados obtenidos, la proporción sexual fue de 0.8:1 (macho:hembra); la reproducción fue observada durante todo el año, pero sobre todo en la primavera y el verano. El hábito alimentario fue piscívoro. Los parámetros de crecimiento y mortalidad fueron estimados en: L∞=35.18cm, k=0.32/año; longevidad= 9.3, Z=1.25/año, M=0.63/año y F=0.62/año. La relación longitud-peso fue: Wt=-3.1663+2.7456lnLp. El análisis de rendimiento por recluta estimó los siguientes valores: E=0.496, Emax=0.916, E0.1=0.701 y E0.5=0.378. Puede concluirse que la población de H. malabaricus en la región estudiada todavía no está siendo altamente explotada.