Ciencias Marinas最新文献

{"title":"Impacts of boat mooring disturbance on productivity and respiration in rhodolith beds from Catalina Island, USA","authors":"Dillon Dolinar","doi":"10.7773/cm.v46i4.3135","DOIUrl":"https://doi.org/10.7773/cm.v46i4.3135","url":null,"abstract":"Aggregations of rhodoliths, habitat-forming, free-living coralline red algae, form beds throughout the world’s oceans. On Santa Catalina Island, California, USA, rhodolith beds occur in protected coves where dense networks of moorings support recreational boating activities. The chains and spreader lines associated with these moorings chronically disturb the benthos, crushing the rhodoliths and reducing biodiversity of rhodolith-associated communities. Here, we examine how mooring disturbance affects rhodolith photosynthesis and respiration and characterize rhodolith-associated invertebrate respiration to better understand how this disturbance affects productivity by the ecosystem. To do this, we used a respiration chamber in the laboratory to measure the amount of oxygen produced and/or consumed by undisturbed (intact) rhodoliths, mooring-disturbed (“crushed”) rhodolith fragments, and laboratory-crushed rhodoliths, and the amount of oxygen consumed by the dominant rhodolith-associated invertebrate taxa. Our results indicate that rhodolith maximum net productivity is significantly reduced and rhodolith respiration is significantly increased by mooring disturbance in the field, but that crushing of the rhodolith thalli alone does not result in immediate changes to either of these measures. Rather, it appears that chronic crushing of rhodolith thalli, which results in their mortality and rhodolith habitat degradation, is required to elicit these metabolic changes. In addition, we observed variation in respiration rates among the 5 most commonly observed invertebrate taxa within the Catalina Island rhodolith beds, and scaling these respiration rates by each species’ abundance in the rhodolith beds and in adjacent mooring-disturbed (degraded) habitats indicated that mooring disturbance results in a decrease in community respiration by approximately 2.61 mg O2·m·d, with individual species contributing between 0.05 mg O2·m·d and 1.84 mg O2·m·d to this decrease. This study provides insight into the consequences of anthropogenic disturbance on productivity and respiration in these ecologically important habitats.","PeriodicalId":50702,"journal":{"name":"Ciencias Marinas","volume":"46 1","pages":"253-267"},"PeriodicalIF":0.7,"publicationDate":"2020-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42413569","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A sticky thicket of glue cells: A comparative morphometric analysis of colloblasts in 20 species of comb jelly (phylum Ctenophora)","authors":"Nicholas D Leonardi","doi":"10.7773/cm.v46i4.3118","DOIUrl":"https://doi.org/10.7773/cm.v46i4.3118","url":null,"abstract":"Ctenophores in the class Tentaculata are distinct from Cnidarians in that they use sticky, not stinging, tentacles to capture and subdue their prey. The structures that make these tentacles sticky are colloblasts, specialized multicellular adhesive structures for predation. Located on the tentacles, tentacle side-branches (tentilla), or oral tentilla, colloblasts are only found in comb jellies (phylum Ctenophora). To perform comparative anatomy of the diversity of ctenophore colloblasts, specimens were collected from the epito bathypelagic zones near the coasts of central California and the Hawaiian Islands using blue-water divers and remotely operated vehicles. Tentacle samples were immediately fixed in a 4% formalin solution at sea, and then prepared in the lab via secondary fixation in 2% OsO4 for scanning electron microscopy (SEM). Diversity of ultrastructural characteristics was observed using SEM, and the morphometrics of the collosphere, external secretion granules, and spiral filament were recorded for 20 species, within 9 families and 9 genera, including 13 undescribed species. Morphometry of colloblasts reveals that the shape of the collosphere (the organizational unit of sticky granules) falls into 3 classifications: spherical, ellipsoidal, or non-uniform. External secretion granule deposition falls into 2 categories: clustered or patterned; the cap cell membrane was either present or absent. This morphological variation is summarized graphically and will be useful to describe the functional diversity and feeding ecology of the interesting and controversial phylum Ctenophora.","PeriodicalId":50702,"journal":{"name":"Ciencias Marinas","volume":"46 1","pages":"211-225"},"PeriodicalIF":0.7,"publicationDate":"2020-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49131664","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Chemical characterization of the soluble polysaccharides of the red alga Acanthophora spicifera from La Paz Bay, Baja California Sur, México","authors":"Valérie Chantal Gabrielle Schnoller, G. Hernández-Carmona, E. Hernández-Garibay, J. López-Vivas, M. Muñoz-Ochoa","doi":"10.7773/CM.V46I3.3090","DOIUrl":"https://doi.org/10.7773/CM.V46I3.3090","url":null,"abstract":"espanol\"Acanthophora spicifera\" es un alga roja invasiva que recientemente fue detectada en la bahia de La Paz, Baja California Sur, Mexico, donde se ha desarrollado en grandes biomasas. Debido a que es una nueva especie en la region, se desconocen las caracteristicas y las propiedades de los polisacaridos solubles (PS) que contiene . Con el proposito de determinar el contenido, la composicion quimica y las propiedades de los PS de A. spicifera, durante el ano 2013, se realizaron muestreos mensuales en punta Roca Caimancito en la bahia de La Paz, y se extrajeron y caracterizaron los PS nativos y los PS con tratamiento alcalino. El tratamiento alcalino redujo el rendimiento y modifico la composicion de los PS de A. spicifera. Los polisacaridos obtenidos antes o despues del tratamiento alcalino fueron de baja viscosidad y no gelificaron. En concordancia con los resultados obtenidos, la razon molar de los componentes (galactosa, 3,6-anhidrogalactosa, sulfatos [Gal:3,6-AG:sulfatos]) para los polisacaridos nativos (1.00:0.30:0.23) y los polisacaridos con tratamiento alcalino (1.00:0.30 :0.17) mostro que los PS de A. spicifera poseen una menor proporcion de sulfatos que la que corresponde a los polisacaridos que pertenecen a los carragenanos, pero mayor que la que corresponde a los polisacaridos pertenecientes al agar verdadero. Los espectros obtenidos de la espectrometria infrarroja con transformada de Fourier de los PS mostraron senales caracteristicas para galactanos sulfatados, con la presencia de acido piruvico; despues del tratamiento alcalino, se observaron senales caracteristicas para polisacaridos del tipo agar (agaroideo). Aunque los polisacaridos de A. spicifera no tienen propiedades gelificantes, es necesario realizar estudios adicionales para determinar la estructura de los PS que contiene esta especie con el proposito de encontrar usos apropiados para este recurso. English\"Acanthophora spicifera\" is an invasive red alga that was recently detected in La Paz Bay, Baja California Sur, Mexico, where it has developed into a large biomass. Because it is a new species in the region, the characteristics and properties of the soluble polysaccharides (SPs) that it contains are unknown. To determine the content, chemical composition, and properties of SPs in A. spicifera, monthly samplings were carried out in 2013 at Point Roca Caimancito in La Paz Bay, and native and alkali-treated polysaccharides were extracted and characterized. The alkaline treatment produced lower yields and modified the composition of A. spicifera SPs. The polysaccharides obtained before or after the alkaline treatment had low viscosity and did not have gelling properties. In line with the obtained results, the molar ratio of components (galactose, 3,6-anhydrogalactose, sulfates [Gal:3,6-AG:sulfates ]) for native (1.00:0.30:0.23) and alkali-treated (1.00:0.30:0.17) polysaccharides showed that A. spicifera SPs have a lower proportion of sulfates than that in polysaccharides bel","PeriodicalId":50702,"journal":{"name":"Ciencias Marinas","volume":"46 1","pages":"165-176"},"PeriodicalIF":0.7,"publicationDate":"2020-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41614552","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A simple method for the genetic identification of commercially important species in the Opisthonema genus Gill, 1861 in the southern Gulf of California","authors":"Carlos Iván Pérez-Quiñonez, C. Quiñonez-Velázquez, F. García-Rodríguez","doi":"10.7773/CM.V46I3.3059","DOIUrl":"https://doi.org/10.7773/CM.V46I3.3059","url":null,"abstract":"espanolSe aplico la tecnica de reaccion en cadena de la polimerasa-polimorfismos de longitud de fragmentos de restriccion (PCR-RFLP, por sus siglas en ingles) para identificar 3 especies del genero Opisthonema ( Opisthonema bulleri , Opisthonema medirastre y Opisthonema libertate ) en la region sur del golfo de California. Se disenaron 2 pares de iniciadores especificos para amplificar el gen mitocondrial COI y se seleccionaron 3 enzimas de restriccion ( Hpa II, Rsa I y Ava II) para comparar los patrones de RFLP entre las especies. Diferentes niveles de polimorfismo fueron detectados entre las muestras. Se generaron perfiles de restriccion especificos faciles de analizar, los cuales pudieran distinguir de manera inequivoca las 3 especies objetivo. El enfoque llevado a cabo aqui usando PCR-RFLP es relativamente barato, rapido y robusto, y proporciona una tecnica util para la identificacion de las especies del genero Opisthonema. . EnglishThe polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) technique was used to identify 3 species in the genus Opisthonema ( Opisthonema bulleri , Opisthonema medirastre , and Opisthonema libertate ) in the southern Gulf of California. Two specific primer pairs were designed to amplify the COI mitochondrial gene and 3 restriction enzymes ( Hpa II, Rsa I, and Ava II) were selected to compare the RFLP patterns among the species. Different polymorphism levels were detected among samples. Easily analyzed specific restric- tion profiles were created, which differentiated unequivocally among the 3 target species. The approach undertaken here using PCR-RFLP is relatively cheap, fast, and robust, providing a useful technique for the identification of species in the genus Opisthonema. .","PeriodicalId":50702,"journal":{"name":"Ciencias Marinas","volume":"46 1","pages":"145-154"},"PeriodicalIF":0.7,"publicationDate":"2020-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43430672","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of frequency and feeding time on growth, food utilization, somatic indexes and survival of juvenile white snook Centropomus viridis","authors":"María Isabel Abdo-de la Parra, L. E. Rodríguez-Ibarra, L. Ibarra-Castro, J. M. Martínez-Brown, G. Velasco-Blanco","doi":"10.7773/CM.V46I3.3089","DOIUrl":"https://doi.org/10.7773/CM.V46I3.3089","url":null,"abstract":"espanolEl robalo blanco del pacifico, \"Centropomus viridis\", se considera como una especie con alto potencial para su cultivo en Mexico por su alto valor economico y gran demanda en el mercado nacional. El crecimiento de los peces en cultivo depende, en gran medida, del regimen alimenticio, el cual incluye, frecuencia, tasa, tiempo y ritmo de alimentacion. El presente trabajo tuvo como objetivo determinar la frecuencia y la hora apropiada de alimentacion de juveniles de C. viridis en cultivo para optimizar el crecimiento y la supervivencia. Se utilizaron juveniles de 0.36 ± 0.01 g para evaluar de 1 a 5 frecuencias de alimentacion ad libitum por dia, con intervalos de 3 a 24 h, durante 6 semanas. Se determino el peso ganado (PG), la tasa de crecimiento (TC), la tasa especifica de crecimiento (TEC), la tasa de conversion alimenticia (TCA), la tasa de eficiencia alimenticia (TEA), el coeficiente de variacion (CV), el indice hepatosomatico (IH), el indice de grasa peritonea l (IGP) y la supervivencia (S) de los juveniles. La TC y la TEC de los juveniles alimentados 3 veces al dia, independientemente de las horas de alimentacion, no presentaron diferencias significativas con respecto a los resultados obtenidos para los juveniles alimentados 5 veces al dia. La TCA fue significativamente mayor y la TEA significativamente menor en los tratamientos con juveniles alimentados una sola vez al dia en comparacion con el resto de los tratamientos. No se encontraron diferencias significativas en CV, IH y S entre los tratamientos. El IGP solo presento diferencias significativas entre los juveniles alimentados 1 y 5 veces al dia. Con base en los resultados obtenidos en el presente estudio, se sugiere que los juveniles de C. viridis se alimenten 3 veces al dia, con un intervalo de 6 h entre cada toma. Estos resultados ayudaran en el desarrollo de la biotecnologia de cultivo de esta especie. EnglishThe Pacific white snook, \"Centropomus viridis\", is considered a species with high farming potential in Mexico due to its high economic value and overall demand in the national market. Growth in farmed fish is largely determined by the dietary regimen, which includes feeding frequency, rate, time, and cycle. The aim of the present study was to determine the feeding frequency and appropriate feeding time for farmed C. viridis juveniles in order to optimize growth and survival. Juveniles weighing 0.36 ± 0.01 g were used to evaluate 1 and up to 5 ad-libitum feeding frequencies per day, with 3 to 24-h intervals, for 6 weeks. Gained weight (GW), growth rate (GR), specific growth rate (SGR), food conversion ratio (FCR), feeding efficiency rate (FER), coefficient of variation (CV), hepatosomatic index (HI), peritoneal fat index (PFI), and survival (S) were determined for juveniles. Regardless of the feeding hours, no significant differences were found in the GR and SGR values between juveniles fed 3 times a day and those fed 5 times a day. FCR was significantly higher and FER sig","PeriodicalId":50702,"journal":{"name":"Ciencias Marinas","volume":"46 1","pages":"155-163"},"PeriodicalIF":0.7,"publicationDate":"2020-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45551052","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Shell dimension-weight relationships in the blood cockle Larkinia grandis (Bivalvia: Arcidae) on the southeastern coast of the Gulf of California","authors":"M. I. Sotelo-Gonzalez, C. Sepúlveda, R. Sánchez-Cárdenas, L. A. Salcido-Guevara, M. García-Ulloa, A. Góngora-Gómez, J. A. Hernández-Sepúlveda","doi":"10.7773/CM.V46I3.3145","DOIUrl":"https://doi.org/10.7773/CM.V46I3.3145","url":null,"abstract":"espanolEl berberecho \"Larkinia grandis\" es un recurso comercialmente importante en el golfo de California, pero hay poca informacion disponible acerca de esta especie. En este estudio, se evaluaron las interacciones entre el peso corporal (BW) y la longitud (SL), la altura (SH) y el ancho (SW) de la concha en una poblacion de L. grandis en el golfo de California, Mexico. Se recolectaron a mano 80 berberechos mensualmente, desde agosto de 2017 hasta julio de 2018, de cerca y/o debajo de los arboles de mangle, en la costa sureste del golfo de California. El intervalo de medidas de las conchas (SL = 142.00–44.57 mm, SH = 85.50–31.15 mm, SW = 76.56–32.03 mm) indica que la poblacion muestreada estaba dominada por especimenes adultos. Solo el coeficiente de variacion para BW exhibio alta dispersion (23%–45%). Las relaciones potenciales de BW con SL, SH y SW no fueron lineales. La interaccion mas fuerte se encontro entre BW y SW (R² = 0.934); la relacion BW–SW describio mejor el crecimiento de este arcido. Todas las relaciones entre la dimension y el peso de la concha fueron significativas (P ≤ 0.05), lo cual indica tanto crecimiento alometrico negativo (SL–SW y SH–SW) como positivo (SL–SH, BW–SL, BW–SH y BW–SW). Los valores de b oscilaron entre 0.8950, para la relacion LogSH–LogSW, y 2.6240, para la interaccion LogBW–LogSH. Esta informacion preliminar es util para desarrollar estrategias de conservacion y explotacion sostenible para esta especie de importancia economica en la region estudiada. EnglishThe blood cockle \"Larkinia grandis\" is a commercially important resource in the Gulf of California, but little information is available on this species. In this study, the interactions between body weight (BW) and shell length (SL), height (SH), and width ( SW) were evaluated in a L. grandis population in the Gulf of California, Mexico. Eighty cockles were hand-picked monthly from August 2017 to July 2018 near and/or under mangrove trees on the southeastern coast of the Gulf of California. The range of shell measurements (SL = 14 2.00–44.57 mm, SH = 85.50–31.15 mm, SW = 76.56–32.03 mm) indicates that the sampled population was dominated by adult specimens. Only the coefficient of variation for BW exhibited high dispersion (23%–45%). The potential relationships between BW and SL, SH, and SW were non-linear. The strongest interaction was found between BW and SW (R² = 0.934), with the BW–SW relationship best describing the growth of this ark clam. All shell dimension–weight relationships were significant (P ≤ 0.05), indicating both negative (SL–SW and SH–SW) and positive (SL–SH, BW–SL, BW–SH, and BW–SW) allometric growth. The b values ranged from 0.8950, for the LogSH–LogSW relationship, to 2.6240, for the LogBW–LogSH interaction. This preliminary information is useful for developing conservation and sustainable exploitation strategies for this species, which is of economic importance to this region.","PeriodicalId":50702,"journal":{"name":"Ciencias Marinas","volume":"46 1","pages":"185-192"},"PeriodicalIF":0.7,"publicationDate":"2020-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43420619","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Fibropapillomatosis in free-ranging green sea turtles (Chelonia mydas) off the central coast of Veracruz, Mexico","authors":"Emilio A Suárez-Domínguez","doi":"10.7773/cm.v46i2.3043","DOIUrl":"https://doi.org/10.7773/cm.v46i2.3043","url":null,"abstract":"espanolLa fibropapilomatosis (FP) es una enfermedad neoplasica que afecta a las tortugas marinas en aguas tropicales. Los individuos juveniles de tortuga verde (Chelonia mydas) parecen ser los mas afectados por los tumores cutaneos, que no son malignos, pero dependiendo de su numero, tamano y ubicacion, pueden comprometer la supervivencia. La prevalencia de la FP en tortugas marinas ha incrementado en las decadas pasadas en zonas como Espirito Santo (Brasil) y Texas (EUA), pero en Mexico pocos casos han sido documentados a la fecha. Durante 2017–2018 se registro por primera vez una prevalencia de FP del 12.2% en tortugas de vida libre en el Parque Nacional Sistema Arrecifal Veracruzano, un area sujeta a la presion ambiental y la presion antropica. De acuerdo con el analisis histopatologico de una muestra de tejido, los tumores fueron consistentes con las caracteristicas de fibropapilomas. Los tumores no fueron severos (0.01–7.16 cm), pero la mayoria tuvo una apariencia verrugosa y se encontraron en las aletas y los ojos, lo que podria representar un riesgo potencial para la salud de los juveniles. Se recomienda continuar el monitoreo de esta poblacion, y la informacion aportada aqui puede servir de base para estudios futuros en aguas mexicanas del golfo de Mexico, en donde la FP no habia sido reportada aun. EnglishFibropapillomatosis (FP) is a neoplastic disease affecting marine turtles around the tropics. Juvenile green sea turtles (Chelonia mydas) seem to be the most affected by the cutaneous tumors, which are not malignant but depending on their number, size, and location, can hamper survival. FP prevalence in sea turtles has increased over the past few decades in areas such as Espirito Santo (Brazil) and Texas (USA), but in Mexico few instances have been documented to date. Here we report a 12.2% FP prevalence in free-ranging turtles captured during 2017–2018 in the Veracruz Reef System National Park, a previously unreported site in Mexico, which is subject to environ-mental and anthropogenic pressures. Histopathological analysis of one tissue sample revealed tumors were consistent with the characteristics of fibropapillomas. They were not severe (0.01–7.16 cm), but the majority had a verrucous appearance and were mainly found on the flippers and eyes, being potentially detrimental to the health of juvenile turtles. We recommend continued monitoring of this population, and the information provided here can serve as a baseline for future studies in this area of the Gulf of Mexico, where FP had not been reported.","PeriodicalId":50702,"journal":{"name":"Ciencias Marinas","volume":"46 1","pages":"133-143"},"PeriodicalIF":0.7,"publicationDate":"2020-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46196051","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of the octopus fishery on the American horseshoe crab population in the Ría Lagartos Biosphere Reserve, Mexico","authors":"J. S. Gío, G. A. Ramírez, Héctor Javier Ortiz León, R. Bustillos, Carmen Olivia Rosas Correa, José Manuel Castro Pérez","doi":"10.7773/cm.v46i2.2992","DOIUrl":"https://doi.org/10.7773/cm.v46i2.2992","url":null,"abstract":"espanolSe ha documentado que la cacerolita de mar Limulus polyphemus se captura de forma ilegal para uso como carnada de Octopus spp. en algunas localidades de la peninsula de Yucatan, Mexico. Para conocer si la pesqueria de pulpo pudiese tener una influencia negativa en las poblaciones de este limulo, se muestrearon organismos de L. polyphemus 2 veces al ano, antes y despues del comienzo de la temporada anual de pulpo, durante 4 anos consecutivos (2015–2018) en Rio Lagartos y San Felipe, situados en la Reserva de la Biosfera Ria Lagartos (RBRL), Yucatan. Se trazaron cuadrantes perpendiculares a la vera del manglar y se midieron los parametros fisicoquimicos del agua (profundidad, temperatura, oxigeno disuelto, pH, salinidad y conductividad electrica), asi como la granulometria del sedimento marino (mediante el tamizado de Folk). Se registro el numero de individuos vivos, el numero de hembras y la longitud promedio. No se encontraron diferencias significativas en los parametros fisicoquimicos del agua ni en la sedimentologia registrada (P > 0.05). Los muestreos evidenciaron pocos organismos por sitioestudiado: 22 en Rio Lagartos y 24 en San Felipe, ambos resultados antes de iniciada la temporada de pulpo de 2017. En los muestreos poste-riores al inicio de la temporada de pulpo de 2018, solo se observaron 2 organismos en Rio Lagartos y ninguno en San Felipe. Los resultados evidenciaron una disminucion significativa en el numero de ejemplares vivos de L. polyphemus despues de iniciada la temporada de pulpo, asi como tambien una disminucion en la longitud promedio de los organismos, lo que sugiere un efecto negativo en las poblaciones de la cacero-lita de mar derivado de las actividades propias de la pesca del molusco. Se requieren mas estudios que integren otros factores fisicoquimicos, biologicos y socioeconomicos para dilucidar la potencial amenaza de esta pesqueria sobre las poblaciones de este limulo en la RBRL. EnglishThe American horseshoe crab, Limulus polyphemus, has been reported to be illegally caught for use as Octopus spp. bait in some localities of the Yucatan Peninsula, Mexico. To learn if the octopus fishery could be negatively influencing the limulus populations in the area,L. polyphemus individuals were sampled twice a year, before and after the annual octopus fishing season, over 4 consecutive years (2015–2018) in Rio Lagartos and San Felipe, both in the Ria Lagartos Biosphere Reserve (RLBR), Yucatan. Quadrants were drawn perpendicular to the mangrove edge, physicochemical parameters in the water (depth, temperature, dissolved oxygen, pH, salinity, and electrical conductivity) were determined, and granulometry of marine sediments was measured (Folk technique). The number of live specimens, number of females, and average length were recorded. No significant differences were found for the physicochemical properties of water or the recorded sedimentology (P > 0.05). Samplings revealed a low number of organisms per site: 22 in Rio Lag","PeriodicalId":50702,"journal":{"name":"Ciencias Marinas","volume":" ","pages":""},"PeriodicalIF":0.7,"publicationDate":"2020-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43149401","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Physiological assessment of 2 color strains of Crassiphycus corneus (J. Agardh) Gurgel, J.N. Norris et Fredericq (Gracilariales, Rhodophyta): Effects of temperature and irradiance","authors":"J. Jofre, N. Navarro, E. Plastino","doi":"10.7773/cm.v46i2.3074","DOIUrl":"https://doi.org/10.7773/cm.v46i2.3074","url":null,"abstract":"Crassiphycus corneus (J.Agardh) Gurgel, J.N.Norris et Fredericq (Gracilariales, Rhodophyta) is a species with high-quality and high yields of polysaccharides and is therefore an important agarophyte on the west coast of the Atlantic Ocean. On the northeastern coast of Brazil, the populations of this species are mostly composed of individuals of the wild red color strain and by some individuals of the green color strain, the latter being scarcely studied. This work characterizes and compares the physiological performance of the wild red strain and the green variant under different temperature and irradiance conditions in the laboratory. The results indicate that the green and red strains are similarly tolerant to low temperatures (18 oC) but intolerant to high temperatures (35 oC). Both strains exhibited the highest growth rate at 25 oC and high irradiance (500 μmol photon·m–2·s–1). Under these conditions, photosynthetic rate and pigment content were similar in both color strains, but growth rates were higher in the red strain. Despite this difference, it is important to highlight that the green strain showed a growth rate of over 10%, which indicates that it could be used for cultures aiming to obtain products with added value.","PeriodicalId":50702,"journal":{"name":"Ciencias Marinas","volume":"46 1","pages":"119-132"},"PeriodicalIF":0.7,"publicationDate":"2020-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41507733","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Influence of partial replacement of fish meal and fish oil with vegetable products on the growth and muscle cellularity of juvenile shi drum, Umbrina cirrosa","authors":"María Dolores Ayala Florenciano, D. Erades, S. Villafranca, M. Arizcun","doi":"10.7773/cm.v46i2.30911","DOIUrl":"https://doi.org/10.7773/cm.v46i2.30911","url":null,"abstract":"Seven-month-old shi drum (Umbrina cirrosa) specimens (mean weight 18.98 g, mean length 11.80 cm) were classified into 2 groups, a control group (C) fed a standard diet and a vegetal group (V) fed a diet with partial replacement of fish meal and fish oil by vegetable products. The body and muscle parameters were studied on days 0, 27, and 62 of the experiment. On day 27, body length was similar in both groups, but body weight was significantly lower in group V than in group C. The transverse area of the white muscle was also significantly lower in V than in C. Hypertrophy was higher in C than in V, whereas hyperplasia was higher in V than in C. On day 62, the body parameters showed similar results to those found on day 27. Muscle cellularity was different from that found on day 27, since hypertrophy was higher in V than in C and hyperplasia was higher in C than in V. The feed conversion rate and specific growth rate were similar in both groups, but the daily intake rate was lower in V than in C. Therefore, it seems that the percentage of vegetables in the vegetal feed was excessively high and this caused less acceptance by the fish. The hepatosomatic, viscerosomatic, and intestinal length indices were similar in both groups. Survival was nearly 100% in both groups.","PeriodicalId":50702,"journal":{"name":"Ciencias Marinas","volume":" ","pages":""},"PeriodicalIF":0.7,"publicationDate":"2020-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46446825","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}