Composition and spatial distribution of subtidal decapoda on the "Reef Coast", northeastern Brazil, evaluated through a low-impact visual census technique

Abstract

This study investigated the composition and spatial distribution of the sublittoral decapods on the reefs of Porto de Galinhas Beach, southern coast of Pernambuco, Brazil, through the Underwater Visual Census technique. Data were collected monthly, at night during full-moon tides in low tide periods from June 2004 to May 2005, using SCUBA diving and a visual census with a fixed belt transect (20 m long). Three sampling areas were defined: Confined Waters (low hydrodynamics) with shallow sites (up to 2.5 m deep); Semi-open Water (3 to 6 m deep), influenced by waves and tidal currents (moderate hydrodynamics); and Open Water (7 to 10 m deep), in the breaker zone (high hydrodynamics). A total of 6,287 individuals of 34 species belonging to the infraorders Brachyura (19 species), Achelata and Anomura (5 species each), Caridea (3 species), and Stenopodidea and Astacidea (1 species each) were collected. Two decapod assemblages were distinguished: in a habitat with low hydrodynamics and shallow (Confined) water; and in a habitat with moderate to high hydrodynamics and depths of 3 to 10 m (Semi-open and Open water). At the sites with high hydrodynamics, i.e., the Open-water Area in the breaker zone, decapod diversity was significantly lower than in the other, protected areas on the reef bench. These results suggest that the distribution of subtidal decapods on coastal reefs is influenced by depth and exposure to water stress caused by waves and currents (hydrodynamics). The visual census technique with SCUBA proved to be suitable for ecological studies on subtidal decapods.

Peer Review #1 of "Diversity and abundance of conspicuous macrocrustaceans on coral reefs differing in level of degradation (v0.1)"

“…The diogenid Calcinus tibicen had a similar abundance as M. coryphe on Bonanza, but was the dominant species on Limones. This small hermit crab, which is an omnivorous detritivore (Hazlett, 1981), has also been reported as abundant on shallow coral reefs in Panama (Abele, 1976), Cuba (Martínez-Iglesias & García-Raso, 1999), the Virgin Islands (Brown & Edmunds, 2013), and Brazil (Giraldes, Coelho Filho & Coelho, 2012). Brown & Edmunds (2013) discovered that C. tibicen can live commensally on hydrozoans of the genus Millepora ("fire corals").…”

Recognizing Panulirus meripurpuratus sp. nov. (Decapoda: Palinuridae) in Brazil—Systematic and biogeographic overview of Panulirus species in the Atlantic Ocean

“…The implementation of a low impact monitoring methodology such as nocturnal Underwater Visual Censuses suggested by Giraldes et al (2015a, b) is urgently required to obtain the necessary ecological data about these large lobsters in coastal areas. The use of Underwater Visual Censuses has proved successful in obtaining ecological indexes for decapod species including spiny lobsters (Faria Júnior et al 2007;Lozano-Álvarez et al 2007;Rios-Lara et al 2007;Bertelsen et al 2009;Teschima et al 2012;Giraldes et al 2012Giraldes et al , 2015aGiraldes et al , 2015b. These in-situ studies can provide important ecological information which will aid the protection of threatened lobster species such as; intensity and seasonality of recruitment, differences in populations between sites, foraging habits, feeding behaviour, seasonal changes, spatial distribution, lunar influence, anthropogenic influence, niche differentiations, among others.…”

“…The natural recruitment ratio of new specimens into the population for this species in Brazil is uncertain, as biological data has traditionally been provided by analysis conducted by the fishing industry. It is important to report that the recruitment of this species happens in shallow coastal reefs and as suggested by Giraldes et al (2012Giraldes et al ( , 2015a, it is possible to monitor this large lobster in coastal areas using nocturnal underwater visual cense and obtain information about species recruitment using low impact methods.…”

“…(Based in Ivo & Pereira 1996;Rocha et al 1997;Melo 1999;George 2006;Silva & Fonteles-Filho 2011;Giraldes et al 2012Giraldes et al , 2015ab;as P. argus in Brazil).…”

Composition, density, and shell use of hermit crabs (Crustacea: Paguroidea) from subtidal boulder fields in southeastern Brazil

“…In contrast, the use of scientific scuba diving to study decapods is an important addition to complement the traditional methodologies employed; it can be used for creating a decapod checklist and generally represents an important tool to study and monitor decapod assemblages in reef environments (Giraldes et al, 2012(Giraldes et al, , 2015. During the last decade, an increasing number of studies in Brazil with decapods were made using scuba diving (Bouzon & Freire, 2007;Alves et al, 2012;Giraldes et al, 2015;Soledade et al, 2015).…”