Secondary production ofPrionospio caspersi (Annelida: Polychaeta: Spionidae)

Abstract

The annual somatic production of Prionospio caspersi Laubier was estimated, between July 1986 and, at a sandy shallow-bottom station in the area facing the Po River Delta, Italy, where this species is one of the most abundant. Primary recruitment occurs in summer, and maturation of gametes the following spring. Body sizes were estimated from the surface area of the anterior end of worms, projected onto a monitor and recorded using a digitizer tablet. Measurements, to the tenth setiger, were correlated with total length, total body surface area and AFDW. The annual production was 8.06 g m -2 yr-1 (AFDW) and the production:biomass (P:B) ratio 4.09. The results are discussed in relation to some physical and chemical features of the environment, stressing differences with the life cycle of other coexisting populations.

Life Cycle, Growth and Secondary Production in a Brackish‐Water Population of the PolychaeteNotomastus latericeus (Capitellidae)in the Mediterranean Sea

“…(1989), who reported higher values, but in a laboratory population. The obtained P : B ratio seems to be low, especially if compared with that of other annual species (CARRASCO & ARCOS, 1980;PRICE & WARWICK, 1980;OYENEKAN, 1986;1987;AMBROGI, 1990). Following the equation of ROBERTSON with a P : B ratio equal to 4.5.…”

“…Moreover, production was lower in 1990 than in 1991, at least until July. This production value is not very high when compared with other polychaete species (WARWICK et ul., 1978;CARRASCO & ARCOS, 1980;PRICE & WARWICK, 1980;KRISTENSEN, 1984;VALDERHAUG, 1985; AMBROGI, 1990), especially considering the fast growing of the species and the environment it inhabits. However, comparison is difficult because the species are not all estuarine forms and belong to different families.…”

Population dynamics and production of Scolelepis gaucha (Polychaeta: Spionidae) on the sandy beaches of Southern Brazil

“…Although spionids are one of the most common benthic community species in shallow marine ecosystems (Blake 1983), data on their population dynamics and production are comparatively few (Buchanan & Warwick 1974, Warwick et al 1978, Vazquez & Rojas 1980, Warwick & George 1980, Rees 1983, Tamai 1985, Lambeck & Valentijn 1987, Ambrogi 1990, Steinle et al 1990). To a great extent, this scarcity of numerical data reflects the methodological difficulties in sampling and measuring small, soft-bodied infaunal species with a short life-span.…”

Population dynamics and production of <i>Streblospio benedicti</i> (Polychaeta) in a non-polluted estuary in the Basque coast (Gulf of Biscay)

“…Biomass in Gernika followed the seasonal pattern of density (Fig. 2), as occurred in other Streblospio populations (Sardà and Martín, 1993;Sola, 1997), and for other small size poly-chaetes such as Prionospio caspersi (Ambrogi, 1990). However, density and biomass showed a different seasonal behaviour, sometimes with opposite fluctuations, in the case of large size polychaetes with longer life cycles such as Hediste diversicolor (Sola, 1997;García-Arberas and Rallo, 2002b) or Marenzelleria viridis (Sardà et al, 1995).…”

“…The polychaete body usually appears broken due to sampling and sieving operations, so the use of partial size measurements instead of total length or the number of segments is highly extended in studies of population dynamics and in order to estimate biomass and production (Möller, 1985;Ambrogi, 1990;Sardà and Martin, 1993;Mendez et al, 1997). The width of the fifth thoracic setiger is usually the maximal thoracic width of Streblospio and other spionid species and is generally used as a size estimate (Tamai, 1982;Yokohama, 1990;Sardá et al, 1995).…”