The annual pattern of reproduction of Talitrus saltator (Crustacea: Amphipoda: Talitridae)

Abstract

The reproductive cycle and breeding biology of Talitrus saltator (Montagu), a supralittoral talitrid amphipod, were investigated over a 15 month period on a sandy beach in the Isle of Man. The species is shown to have an annual, univoltine reproductive cycle with a period of high reproductive activity between May and late August. Two generations are present throughout most of the year and the life spans of female and male T. saltator were calculated to be approximately 18 months and 21 months respectively. Initial juvenile growth was rapid, juveniles attaining sexual differentiation within three to four months of hatching. Juvenile growth rates averaged 5–5 mm in 100 days decreasing to 1–3 mm in 100 days after sexual differentiation at around 8.0 mm. The relative brood size of incubating females was shown to be dependent on at least two factors, the length of the female and the stage of embryological development of the brood. It is suggested that photoperiod is the major exogenous factor controlling gonadal maturation and the duration of reproductive activity in T. saltator.

Population structure and dynamics ofOrchestia montagui(Crustacea: Amphipoda) in the Bizerte lagoon (northern Tunisia)

“…Other talitrid species such as T. saltator Bouslama et al 2007), Britorchestia brito and Deshayesorchestia deshayesii (AyariAkkari et al 2014 in press) reproduced following a seasonal pattern. Seasonal variation was also observed in a population of T. saltator on the Atlantic coast (Williams 1978), in O. gammarellus in the Baltic Sea (Persson 1999) and in O. mediterranea in the Medway estuary in the North of Europe. The non-reproductive rest period was observed from October to mid-April (Wildish 1979), but a population from Languedoc ponds (southern Europe) had its rest period from November to mid-March (Louis 1977).…”

“…Seasonal reproduction occurred from February to November for D. deshayesii in the Ionian Sandy Beach in Southern Italy (Prato et al 2009). Williams (1978) showed that populations of T. saltator from Britannic Island had a much shorter reproductive period, from May to the end of August.…”

“…In addition, the population dynamics and structure have focused on populations of Orchestia mediterranea (Louis 1977;Wildish 1979), Deshayesorchestia quoyana (Marsden 1991), Talitrus saltator (Williams 1978;Pavesi et al 2007) Orchestia gammarellus (Persson 1999;Pavesi et al 2007), Platorchestia platensis (Pavesi et al 2007) and Macarorchestia remyi (Pavesi & De Matthaeis 2009).…”

Life history of Talorchestia deshayesii (Amphipoda, Talitridae) in the Ionian sandy beach (southern Italy)

“…In talitrid, it was usual that the females were more numerous than males, e.g. in O. gammarellus (Jones and Wigham, 1993;Persson, 1999); Pseudorchestia brasiliensis (Cardoso and Veloso, 1996), T. saltator (Williams, 1978), and T. capensis (Van Senus, 1988). Gonçalves et al (2003) found a sex ratio different for two populations of T. brito, a sex ratio male biased for a population of the Portuguese coast and a population dominated by the females in Tunisia.…”

“…Many authors have described their spatial distribution and oriented movements in sandy beaches Scapini et al, 1999;Scapini and Quochi, 1992); their behavioural strategies (Fallaci et al, 1999); and their use as an environmental indicator (Rainbow et al, 1989;Moore et al, 1991;Weslawski et al, 1999;Fialkowski et al, 2000). However, there are few studies on thetalitrids'population biology (Williams, 1978;Elkaïm et al, 1985;Van Senus, 1988 Jones andWigham, 1993;Persson, 1999) The talitrid amphipod Talorchestia deshayesii (Audouin, 1826) is a sandhopper, which lives near the supralittoral level of sandy beaches under seaweed. It is a frequently recorded species along the European coasts: in the Mediterranean sea (Dahl, 1946); Baltic sea (Caspers, 1951) and in the North sea (Kalbrink, 1969).…”