Composition and distribution of subtidal and intertidal crustacean assemblages in soft-bottoms of the Ria de Vigo (NW Spain)

Abstract

SUMMARY:The intertidal and subtidal soft-bottoms of the inner area of the Ria de Vigo (NW Spain) were sampled in November and December 1999, and spatial distribution of crustacean species was examined. Environmental variables from water and sediment were measured at each sampling site. Amphipods and myocopids were the numerically dominant orders (49.9 and 26.9% dominance), amphipods accounting for more than 54% of identified taxa. The highest crustacean densities occurred with 55-41 species and 5953.6-4346.4 ind. m -2 in external areas, where the diversity index reached the maximum values. Multivariate techniques revealed that distribution of crustaceans in the inlet was highly dependent on depth. Ordination analysis determined three major assemblages: Intertidal bottoms colonized by seagrasses and subjected to strong variations of salinity were dominated by the amphipod Melita palmata, harpacticoids and the isopod Idotea baltica (Group A). The amphipod Corophium cf. runcicorne and the cumacean Iphinoe tenella predominated in the muddy bottoms of central areas (Group B). These species were also present in the deep muddy bottoms of the mouth of the inlet, with high carbonate and gravel contents, and with the myocopids and the amphipod Microdeutopus cf. armatus displaying maximum dominances (Group C).Keywords: marine crustaceans, macrofaunal composition, soft bottoms, Ensenada de San Simón, Ria de Vigo, Atlantic Ocean.RESUMEN: Composición y distribución de las asociaciones de crustáceos submareales e intermareales en fondos blandos de la Ría de Vigo (NO España). -Los fondos blandos intermareales y submareales de la parte interna de la Ría de Vigo (NO España) fueron estudiados en relación a la distribución de los crustáceos y a las variables ambientales asociadas a sus aguas y sedimentos. Los anfípodos y miocópidos fueron los órdenes más abundantes (49.9 y 26.9%), presentando los anfípodos más del 54% de los taxa identificados. Las mayores densidades de crustáceos aparecieron en las áreas externas, con 55-41 especies y 5953.6-4346.4 individuos por m 2 , alcanzándose aquí los máximos valores de diversidad. Se emplearon técnicas multivariantes para analizar los datos, demostrando que la distribución de los crustáceos en la ensenada dependía principalmente de la profundidad. Se observaron tres principales asociaciones de crustáceos: Los fondos intermareales, colonizados por las fanerógamas marinas Zostera marina y Z. noltii y sometidos a drásticos cambios de salinidad, estuvieron dominados por el anfípodo Melita palmata, los harpacticoideos y el isópodo Idotea baltica (Grupo A). El anfípo-do Corophium cf. runcicorne y el cumáceo Iphinoe tenella predominaron en los fondos fangosos de la zona central (Grupo B). Estas especies también estuvieron presentes en los fondos profundos de la boca de la ensenada, donde los miocópidos y el anfípodo Microdeutopus cf. armatus presentaron sus máximas dominancias (Grupo C).

Abundance and diversity of amphipods (Crustacea: Peracarida) on shallow algae and seagrass in lagoonal ecosystem of the Mediterranean Tunisian coast

“…Some other authors have demonstrated that modification in habitat complexity affects crustacean assemblages (Sanchez-Jerez et al 1999;Ayala and Martin 2003;Vazquez-Luis et al 2008). Indeed, the importance of temperature should be interpreted carefully, since Ysebaert and Herman (2002) pointed out that longterm averages of environmental variables are more important than values obtained during samplings (Cacabelos et al 2010). Nevertheless, the difference in mean density between months can be explained by the ecological preferences of each species.…”

“…Variations in temperature and salinity have been cited by a number of authors as important factors for the occurrence of particular amphipod species (Nevis et al 2009;Mogias and Kevrekidis 2005). In fact, many ecological studies have shown salinity to be the main factor controlling zonation in the structure of the benthic communities (Cacabelos et al 2010). However, Bazairi et al (2003) have emphasized that this is not the main factor in brackish environments.…”

Amphipods from marine cave sediments of the southern Iberian Peninsula: diversity and ecological distribution

“…Studies carried out in the Atlantic zone of the Iberian Peninsula found between 34 and 79 different amphipod species in the northwestern area (Cunha et al 1999, Lourido et al 2008, Cacabelos et al 2010 and 93 species on the southern Portuguese coast (Carvalho et al 2012). On the other hand, in the Mediterranean area, an inventory of soft-bottom amphipods from the east coast of the Iberian Peninsula revealed the presence of 55 different species (de-la-Ossa-Carretero et al 2010).…”

Genetic divergence of tanaidaceans (Crustacea: Peracarida) with low dispersal ability

“…This species is recorded from all over the world, including Australia (Edgar 2008), Bermuda (Greve 1974), California (Richardson 1905, Sieg 1980, Japan (Shiino 1951), Sri Lanka (Stebbing 1905) and Spain (Cacabelos et al 2010). Such a cosmopolitan distribution is highly unlikely for organisms with low dispersal potential, such as tanaids (Larsen 2005), so the presence of a species complex is expected.…”