Fishery and life history of spot-tail mantis shrimp, <i>Squilla mantis</i> (Crustacea: Stomatopoda), in the Gulf of Cadiz (eastern central Atlantic)

Abstract

SUMMARY: Squilla mantis is an economically important species that is mainly caught by the Sanlucar de Barrameda bottom trawl fleet in the Gulf of Cadiz (eastern central Atlantic). Annual landings have ranged between 24 t in 1999 and 600 t in 2003, with a mean value of 269 t for the period 1984-2010. Catches have a marked seasonality, peaking in winter and showing the lowest values in summer. Larval abundance was negatively correlated with depth and distance from the coast but positively correlated with sea surface temperature. No correlation with sea surface salinity was found. The highest larval abundance was observed in June at 20-25 m depth, while adults were mostly found at 30-35 m depth. This species is mainly concentrated in the area of influence of the Guadalquivir River but is very scarce in the rest of the study area. The maturation of the ovary and the activity of the sexual accessory glands begin in early winter. The population is age-structured in three year classes and females reach first maturity within the second year class, at 23.7 mm carapace length.Keywords: Squilla mantis, fisheries, maturation, larvae, Gulf of Cadiz. RESUMEN: Pesquería e historia de vida de la galera, Squilla mantiS (CrustaCea: stomatoPoda) en el golfo de Cádiz (atlántiCo Centro-oriental). -La galera Squilla mantis es una especie de importancia económica en el Golfo de Cádiz (Atlántico Centro-oriental), capturada principalmente por la flota de arrastre de fondo de Sanlúcar de Barrameda. Los desembarcos anuales oscilaron entre 24 t en 1999 y 600 t en 2003 con un valor medio de 269 t en el periodo comprendido entre 1984 y 2010. Las capturas tienen una marcada estacionalidad, con un pico máximo en invierno y registrándose los valores más bajos en verano. La abundancia de larvas está negativamente correlacionada con la profundidad y la distancia a costa, mientras que una correlación positiva con la temperatura superficial del mar fue encontrada. No se encontró ninguna correlación con la salinidad superficial. Las mayores abundancias de larvas fueron observadas en junio en estaciones situadas a una profundidad de 20-25 m, mientras que los adultos fueron más abundantes a 30-35 m. Esta especie está principalmente concentrada en el área de influencia del río Guadalquivir, y es muy escasa en el resto del área de estudio. La maduración del ovario y la actividad de las glándulas sexuales accesorias comienzan a principio del invierno. La población está estructurada en tres clases anuales de edad, y las hembras alcanzan la primera madurez sexual dentro del segundo año, que corresponde con una longitud del cefalotórax de 23.7 mm.

Length–weight relationships for 22 crustaceans and cephalopods from the Gulf of Cadiz (SW Spain)

“…Crustacean length was measured to the nearest 0.01 mm from the orbit of the eye to the posterior border of the cephalothorax (carapace length; CL) using a digital caliper. Note that for S. mantis, CL was measured from the median posterior edge of the carapace to the base of the rostrum following Vila et al (2013). All specimens were weighed to the nearest 0.01 g using a digital balance (wet body weight, W).…”

“…For these species, fishing and biological traits have been widely described, e.g. Octopus vulgaris (Silva et al, 2002;Sobrino et al, 2011), Sepia officinalis (Tirado et al, 2003), Eledone moschata (Silva et al, 2004), Loligo vulgaris (Vila et al, 2010), Parapenaeus longirostris (Sobrino et al, 2005) and Squilla mantis (Vila et al, 2013). However, an update of local length-weight relationships of these species is needed since they vary over time and geographically (Merella et al, 1997;Guijarro et al, 2012).…”

Long-Wavelength Reflecting Filters Found in the Larval Retinas of One Mantis Shrimp Family (Nannosquillidae)

“…observ, [18]). Though the daytime depths and migratory behavior of stomatopod larvae have yet to be specifically measured, one study found that collections at 10-200 m daytime depth were sufficient to quantify larval abundance across a geographic region for the species (Squilla mantis, [19]).…”

A study on some population parameters of mantis shrimp (Squilla mantis L., 1758) in Izmir Bay (Aegean Sea)

“…(2012) defined abundance and biological features; and Vila et al . (2013) investigated fishery and life cycle.…”