Variación espacio-temporal de la meiofauna submareal en una playa arenosa nororiental de Venezuela

Abstract

Spatio-temporal variation of subtidal meiofauna in a sandy beach from Northeastern Venezuela. Meiofauna organisms that play an important role in the trophic ecology of soft bottom benthos, have short life cycles and they respond quickly to disturbance and pollution. The present study shows the spatio-temporal variation of subtidal meiofauna (metazoans passing a 500µm sieve but retained on meshes of 40-63µm) in four shallow subtidal stations. Samples were taken in the sandy beach of San Luis, in the Northeastern coast of Venezuela, from October 2005 until September 2006. For this, three replicate sediment core samples (4.91cm 2), were collected monthly to a depth of 10cm into the sediment, and preserved in 6% formalin stained with rose Bengal. Specimens of 14 meiofaunal groups (Foraminifera excluded) were collected, being the nematodes, ostracods and harpacticoid copepods the most abundant. Monthly density was comprised between 64 and 503ind./10cm 2 , and mean density of stations between 173 and 449ind./10cm 2. There is a trend of low densities from October to February (end of the rainy season until the middle of the dry season). The San Luis beach control of the meiofaunal community is shared by climatic conditions and by the biology of the species found. The meiofauna mean density in San Luis beach (263ind./10cm 2) was low when compared to other studies in tropical areas. Rev. Biol.

Spatial and temporal variations of the subtidal meiobenthic community of the central coast of Venezuela

“…However, they compared their results with other studies worldwide, finding a low density for this zone. In fact, by excluding foraminifera quantified in this study, we obtained a meiobenthic density three times higher than the one obtained by Liñero et al (2013) on San Luis beach. However, the richness of foraminifera was similar to that found in Cartagena bay, Colombia (Osorio-Dualiby & Álvarez-León, 2011).…”

“…Although their densities were low, their presence in the meiobenthos could indicate the link between the planktonic and benthic communities, where these planktonic organisms migrate to the bottom to feed on benthic organisms (Schnack-Schiel & Isla, 2005). As in this study, Liñero et al (2013) identified 14 taxa on a beach in eastern Venezuela. The authors excluded foraminifera from their analysis, and found a dominance of nematodes with an average density of 155.80 ± 29.07 ind/10 cm 2 that represented 58.36%, followed by ostracods with 45.60 ind/10 cm 2 (17.10%), and harpacticoid copepods with 41.96 ind/10 cm 2 (15.7%).…”

“…The authors excluded foraminifera from their analysis, and found a dominance of nematodes with an average density of 155.80 ± 29.07 ind/10 cm 2 that represented 58.36%, followed by ostracods with 45.60 ind/10 cm 2 (17.10%), and harpacticoid copepods with 41.96 ind/10 cm 2 (15.7%). Liñero et al (2013) explained the difficulty of making comparisons with other studies due to the methodological differences that exist during Rev. Mar.…”

“…Gourbault et al (1998) pointed out that nematodes are the most dominant group in reef areas, which suggests their need to stay in more stable or protected areas. In fact, Dye & Lasiak (1986) and Liñero et al (2013) found that nematodes had preferences for fine sands. Although the sediments were not characterized in this study, this area is characterized by being of high energy with muddy-sandy sediments (Solé & Vera, 1997, Pereira et al 2020, which explains the abundance values found in this research.…”

“…In Venezuela, only a few studies have been conducted on this community. Woods & Tietjen (1985) analyzed the meiobenthos of the Venezuelan basin; Reyes et al (1999) studied the benthic community in the western side of the country; Martín et al (2007) conducted a baseline study in the eastern part of the country; Vásquez-Suárez et al (2010) analyzed meiofauna temporal variation in Raya Lagoon on Margarita Island;and Liñero et al (2013) studied the spatial and temporal variation of the subtidal meiofauna on a beach in the eastern zone. For this reason, this study proposed to describe the spatial and seasonal variations of the composition and abundance of subtidal meiobenthos in the central coast of Venezuela.…”