Growth and reproductive parameters of Kalliapseudes schubartii in the estuarine region of the Lagoa dos Patos (southern Brazil)

Abstract

Kalliapseudes schubartii (Crustacea: Tanaidacea) is a tube dwelling invertebrate living in estuarine soft bottoms with distribution along the south-east and southern Brazilian and Uruguayan coasts. Individual growth, and reproduction were examined by taking samples for a year in the estuarine region of the Lagoa dos Patos (southern Brazil). The von Bertalanffy model described growth of K. schubartii (K=4.54 y−1, L∞=13.22 mm). Reproductive activity was observed in spring and summer. No relationship was observed between total length of females and brood size. Eggs, embryos, and mancas were often observed in a marsupium. Relative growth analysis showed two levels of allometry in the growth of chelipeds of males.

Mortality of Kalliapseudes schubartii in unvegetated soft bottoms of the estuarine region of the Lagoa dos Patos

“…Moreover, high proportions of brooding females are observed most of year (from spring to early autumn), and these brooding females have up to 47 mancas (juveniles) in the marsupium. Recruitment peaks are observed in spring and summer (Fonseca and D'Incao, 2003), and a small reproductive activity is observed even in winter, which suggests that K. schubartii has continuous reproduction. Continuous reproduction of K. schubartii has also been suggested elsewhere (Leite et al, 2003).…”

“…In the estuarine region of the Lagoa dos Patos, the mean size of the onset maturity (L50) of females is attained rapidly (two months after release from the marsupium) (Fonseca and D'Incao, 2003). Moreover, high proportions of brooding females are observed most of year (from spring to early autumn), and these brooding females have up to 47 mancas (juveniles) in the marsupium.…”

“…To estimate the mortality rate, age determination was performed indirectly by length-based methods. Parameters of individual growth (von Bertalanffy growth model) estimated for this population (Fonseca and D'Incao, 2003) were utilised to convert length to age (t). Instantaneous rate of total mortality (Z) was estimated by length converted catch curve -ln(N/∆t) = a+bt' -where the slope of regression (b) is the estimate of Z, N is the number of individuals in a given length class, ∆t is the time for the individuals growth through that length class and t is the mean age of the individual in that length class (Pauly, 1990).…”

“…This tanaid is both a deposit and filter-feeder that, in turn is prey for several secondary consumers (Bemvenuti, 1997b). In the estuarine region of the 'Lagoa dos Patos' (Patos Lagoon), while individual growth and reproductive parameters of K. schubartii have been previously studied (Fonseca and D'Incao, 2003), mortality rates have never been quantified. Regarding mortality rates, it has been hypothesized that K. schubartii would be the most preyed on when juveniles of fish and crustaceans use the estuarine region as nursery grounds (Bemvenuti, 1997b).…”

Apseudopsis adami, a new species of tanaidacean (Crustacea: Peracarida) from the NW Iberian Peninsula: postmarsupial development and remarks on morphological characters

“…Secondary males have been shown to derive from protogynous development in some cases (Lang 1958;Gardiner 1975), while in other species, they derive from males I which are simply subadults (Bamber 2010), and in other cases, all types of males are reproductive (Hamers and Franke 2000;Fonseca and D'Incao 2003). In Apseudopsis adami the penial tubercle is differentiated in the juvenile stage, and there is no particular reason to consider protogyny.…”