RESUMEN
Functional aspects of biological communities influence ecosystem processes and it is urgent to understand how human disturbances affect functional diversity and ecosystem functions and services. Our purpose was to address the use of different functional metrics of nematode assemblages to evaluate the ecological status of tropical estuaries subjected to different human activities, aiming to advance and improve the knowledge about the usefulness of functional attributes as indicators of environmental quality. Three approaches were compared: functional diversity indexes, single trait, and multi traits using the Biological Traits Analysis. The RLQ + fourth-corner combined method was used to identify relationships among functional traits, inorganic nutrients, and metals concentrations. Lower values of FDiv, FSpe, and FOri indicate a convergence of functions, characterizing impacted conditions. A dominant set of traits was related to disturbance, mainly inorganic nutrient enrichment. All the approaches allowed for the detection of disturbed conditions, however, multi traits was the most sensitive one.
Asunto(s)
Ecosistema , Nematodos , Animales , Humanos , Biodiversidad , Biota , EstuariosRESUMEN
Free-living marine nematodes of continental shelf of Portugal were studied through the goals of the Marine Biodiversity Information System Project (M@rbis 2015). Four species unknown to science and belonging to the families Axonolaimidae, Chromadoridae, Desmodoridae and Xyalidae are described. Besides Hypodontolaimus golikovy, Hypodontolaimus portuguese sp. n. is the only species in this genus which lacks precloacal supplements and gubernaculum but differs from the former mainly in cephalic setae length and amphidial fovea features. Metachromadora aliusa sp. n. doesn't have a unique diagnostic character, differing in many aspects from the other species of the genus instead, mainly teeth number in the buccal cavity, size of the cephalic setae and the amphidial fovea, velum presence in the spicules, number and shape of the precloacal supplements. The main character of Odontophora sinapophysis sp. n. is the absence of apophysis in the gubernaculum. Stylotheristus multipapillatus sp. n. is characterized by the presence of precloacal supplements (papilliform) and the gubernaculum formed by only a piece.