Assessing the feeding ecology of three sympatric squids Illex argentinus, Doryteuthis gahi and Onykia ingens off the Patagonian by combining stomach content and stable isotopic analysis

The Ommastrephidae Illex argentinus, the Loliginidae Doryteuthis gahi and the Onychoteuthidae Onikya ingens are squid species coexisting in the south part of the Patagonian Shelf, interacting for similar feeding resources. In the present study, we analyzed the feeding ecology, trophic position and trophic relationships of these three species by combining stomach content and stable isotopic approximations. In particular, stomach content and isotopic analysis were carried out on 20 D. gahi, 20 I. argentinus and 21 O. ingens collected from May 6th and 8th 2013 at depths between 147 and 220 m. The results indicated that the feeding habits of small and larger squids were different in the three species. The two main prey species for small D. gahi individuals were the euphausid Euphausia sp. and the amphipod Eutemisto gaudichaudi, and the main prey for larger D. gahi individuals were a fish and the Munididae Munida subrugosa. The main prey group of small I. argentinus individuals was the amphipod E. gaudichaudi and the myctophid fish, and the main prey for larger size I. argentinus individuals were the paralepididae Arctozenus risso and the Notothenidae Patagonotothen ramsayi, secondly by the squid group. Small O. ingens individuals fed on Micromesistius australis and Notophysis marginata while larger O. ingens individuals fed on Lampanyctus australis and Notoscopelus sp. D. gahi showed higher δ15N values than the other two species and small and larger D. gahi individuals showed similar isotopic values. The δ15N values of I. argentinus and O. ingens were higher for larger individuals. Finally, D. gahi differed in its δ13C values from I. argentinus and O. ingens and the less depleted δ13C values were found in the larger in D. gahi individuals. The results indicate that the three squid species preyed on organisms with similar trophic position, but due to their voracity and their active predation on similar trophic resources, small size individuals segregate their trophic niche from the larger ones. It is important to note that the δ13C values revealed that larger D. gahi individuals had a different distribution in the water column, which probably is a response of the reproductive activity of mature squid near to the surface water.Universidad Nacional Autónoma de Méxic

Griferías para duchas

Documento producto del convenio SENA- Asoceramistas en el que se explica que es una ducha sencilla, sus características, partes, funcionamiento y los materiales, herramientas y métodos para su instalación y mantenimientoDocument product of the agreement SENA- Asoceramistas in which it is explained that it is a simple shower, its characteristics, parts, operation and the materials, tools and methods for its installation and maintenanceGeneralidades -- Proceso técnico de instalación -- Materiales, herramientas y equipo -- Mantenimiento -- Recomendaciones técnicas -- Glosario de términos técnicos24 página

Teleducha con válvula

Documento producto del convenio SENA- Asoceramistas en el que se explica que es una tele ducha con valvula, sus características, ubicación, partes, funcionamiento y los materiales, herramientas y métodos para su instalación y mantenimientoGeneralidades -- Proceso técnico de instalación -- Materiales, herramientas y equipo -- Recomendaciones técnicas14 página

Teleducha con mezclador

Documento producto del convenio SENA- Asoceramistas en el que se explica que es una tele ducha con mezclador, sus características, ubicación, partes, funcionamiento y los materiales, herramientas y métodos para su instalación y mantenimientoDocument product of the agreement SENA- Asoceramistas in which it is explained that it is a shower with mixer, its characteristics, location, parts, operation and the materials, tools and methods for its installation and maintenanceGeneralidades -- Proceso técnico de instalación -- Materiales, herramientas y equipo -- Mantenimiento -- Recomendaciones técnicas -- Glosario de términos técnicos23 página

Mezclador 8''. Cierre corriente

Documento producto del convenio SENA- Asoceramistas en el que se explica que es una mezclador de cierre corriente para ducha, sus características, partes, funcionamiento, tipos y los materiales, herramientas y métodos para su instalación y mantenimientoDocument product of the agreement SENA- Asoceramistas in which it is explained that it is a mixer of current closure for shower, its characteristics, parts, operation, types and materials, tools and methods for its installation and maintenanceGeneralidades -- Proceso técnico de instalación -- Materiales, herramientas y equipo -- Mantenimiento -- Recomendaciones técnicas -- Glosario de términos técnicos24 página

Mezclador monocontrol

Documento producto del convenio SENA- Asoceramistas en el que se explica que es una mezclador monocontrol para ducha, sus características, partes, funcionamiento y los materiales, herramientas y métodos para su instalación y mantenimientoDocument product of the agreement SENA- Asoceramistas in which it is explained that it is a monocontrol mixer for shower, its characteristics, parts, operation and the materials, tools and methods for its installation and maintenanceGeneralidades -- Proceso técnico de instalación -- Materiales, herramientas y equipo -- Mantenimiento -- Recomendaciones técnicas23 página

Mezclador 8''. Cierre rápido

Documento producto del convenio SENA- Asoceramistas en el que se explica que es un mezclador de cierre rápido para ducha, sus características, partes, funcionamiento y los materiales, herramientas y métodos para su instalación y mantenimientoDocument product of the agreement SENA- Asoceramistas in which it is explained that it is a mixer of fast closing for shower, his characteristics, parts, operation and the materials, tools and methods for his installation and maintenanceGeneralidades -- Proceso técnico de instalación -- Materiales, herramientas y equipo -- Mantenimiento -- Recomendaciones técnicas – Glosario de términos técnicos23 página

Desagüe para bañera

Documento producto del convenio SENA- Asoceramistas en el que se explica que es un desagüe para bañera, sus características, partes, funcionamiento y los materiales, herramientas y métodos para su instalación y mantenimientoDocument product of the agreement SENA- Asoceramistas in which it is explained that it is a drain for bathtub, its characteristics, parts, operation and the materials, tools and methods for its installation and maintenanceGeneralidades -- Proceso de instalación -- herramientas y equipo -- Recomendaciones técnicas – Glosario de términos técnicos17 página

Relaciones tróficas entre el calamar gigante Dosidicus gigas y el pez luminoso Vinciguerria lucetia en el sistema de la corriente de Humboldt de Perú

Acoustic surveys for assessing the biomass and distribution of the jumbo squid (Dosidicus gigas) and the lightfish (Vinciguerria lucetia) were carried out in the Humboldt Current System of Peru in 2007 and 2008. At the same time, 937 jumbo squid were caught and their stomach contents analyzed. The diet of the jumbo squid was dominated by mesopelagic fish. The first component of their fish diet was V. lucetia and the second component was the myctophid fish Diogenichthys laternatus. Acoustic biomass estimates of these species show that V. lucetia is an important component in aggregative structures in the Humboldt Current System of Peru and its distribution and movements are closely related to the migratory movements of the jumbo squid. The trophic relationship observed between D. gigas and V. lucetia promotes an increase in jumbo squid biomass and, has a positive trophic effect on the ocean ecosystem.La biomasa de calamar gigante Dosidicus gigas y el pez mesopelágico Vinciguerria lucetia se obtuvo a partir de detección acústica en la Corriente de Humboldt de Perú durante 2007 y 2008. Simultáneamente, 937 calamares fueron capturados y se les analizó el contenido estomacal. La dieta de D. gigas estuvo dominada por peces, siendo V. lucetia el principal componente y en segundo lugar el mictófido Diogenichthys laturnatus. A partir de la evaluación de la biomasa de ambas especies, estimada por el método acústico, se observó que V. lucetia es uno de los principales componentes en el sistema de la Corriente de Humboldt de Perú y sus patrones de distribución y movimientos espacio-temporal están fuertemente relacionados a los desplazamientos migratorios del calamar. Estas relaciones tróficas promueven un incremento de la biomasa de D. gigas que es resultado de un patrón similar en V. lucetia, lo que propicia un efecto trófico positivo en el ecosistema oceánico

The significance of cephalopod beaks as a research tool: An update

The use of cephalopod beaks in ecological and population dynamics studies has allowed major advances of our knowledge on the role of cephalopods in marine ecosystems in the last 60 years. Since the 1960’s, with the pioneering research by Malcolm Clarke and colleagues, cephalopod beaks (also named jaws or mandibles) have been described to species level and their measurements have been shown to be related to cephalopod body size and mass, which permitted important information to be obtained on numerous biological and ecological aspects of cephalopods in marine ecosystems. In the last decade, a range of new techniques has been applied to cephalopod beaks, permitting new kinds of insight into cephalopod biology and ecology. The workshop on cephalopod beaks of the Cephalopod International Advisory Council Conference (Sesimbra, Portugal) in 2022 aimed to review the most recent scientific developments in this field and to identify future challenges, particularly in relation to taxonomy, age, growth, chemical composition (i.e., DNA, proteomics, stable isotopes, trace elements) and physical (i.e., structural) analyses. In terms of taxonomy, new techniques (e.g., 3D geometric morphometrics) for identifying cephalopods from their beaks are being developed with promising results, although the need for experts and reference collections of cephalopod beaks will continue. The use of beak microstructure for age and growth studies has been validated. Stable isotope analyses on beaks have proven to be an excellent technique to get valuable information on the ecology of cephalopods (namely habitat and trophic position). Trace element analyses is also possible using beaks, where concentrations are significantly lower than in other tissues (e.g., muscle, digestive gland, gills). Extracting DNA from beaks was only possible in one study so far. Protein analyses can also be made using cephalopod beaks. Future challenges in research using cephalopod beaks are also discussed.Cephalopod International Advisory Counci