Embryonic life of the loliginid squid Loligo vulgaris: comparison between statoliths of Atlantic and Mediterranean populations (original) (raw)
Related papers
The effect of temperature on growth of early life stages of the common squid Loligo vulgaris
The squid Loligo vulgaris has an extended spawning season within the upwelling system off north-west Portugal, and its paralarvae may thus develop under a wide range of environmental conditions. Both temperature and salinity are expected to affect the metabolism of young squid and we tested their effects on growth during the embryonic and post-hatching phase, based on measurements of growth increments in statoliths of juveniles and adults, using generalized additive models. There was no evidence that statolith increments representing early growth become unreadable in adult statoliths. Variability in the statolith size at hatching was weakly but significantly related to the variables in the model. On the other hand, the effects on statolith growth of both sea surface temperature and of sea bottom temperature were significant during early post-hatching life. Thicker increments are deposited in the statoliths of squid living under higher temperatures, which results in summer hatchers having larger statoliths at the age of 90 days. Inspection of the statolith accretion pattern, using a piecewise linear regression method, revealed an ontogenetic shift in increment width, which may be an indication of the age of transition from paralarva to juvenile. On this basis, it is suggested that the planktonic stage lasts 60 or 90 days, depending on whether the paralarvae lived at higher (.158C) or lower (,158C) sea surface temperatures. The life strategy under warmer conditions potentially favours survival by reducing the duration of the vulnerable planktonic phase. (2006) Oceanography and fisheries of the Canary Current/Iberian region of the eastern North Atlantic. In Brink K.H. and Robinson A.R. (eds) The sea. Volume 14B: the global coastol ocean. Cambridge, MA: Harvard University Press, pp. 877-931. Arkhipkin A.I. (2004) Diversity in growth and longevity in short-lived animals: squid of the suborder Oegopsina. Marine and Freshwater Research 55, 341-355. Arkhipkin A.I. (2005) Statoliths as 'black boxes' (life recorders) in squid. Marine and Freshwater Research 56, 573 -583.
Helgoland Marine Research, 2011
Early life stages of cephalopods are somewhat complex due to the life history strategy or species specificity of generalized ontogenetic patterns and processes. This work aimed to determine the time length of embryonic development at different temperatures, and if the egg size is a determinant of hatchling size in Sepiola atlantica d 0 Orbigny, 1839-1842. Successful hatching occurred in 98.5-100% of the eggs for each female. As seen in other coleoid cephalopods, temperature determines the amount of time for embryonic development in S. atlantica, and the obtained data were very similar to other coleoid cephalopods. Developmental times for temperatures at 13 ± 0.4°C, 18 ± 0.3°C and 16.4 ± 1.1°C were 61.8 ± 3.8, 22.6 ± 1.7 and 40.1 ± 4.8 days. The duration of embryonic development and hatchling mantle length was not strictly related. The egg volume was positively related to hatchling mantle length. Our results provide new records on the duration of embryogenesis and other information on reproductive patterns in this species. Some hatching and post-hatching behaviour are shown and discussed.
Moreno et al 2012 squid early growth
The squid Loligo vulgaris has an extended spawning season within the upwelling system off north-west Portugal, and its paralarvae may thus develop under a wide range of environmental conditions. Both temperature and salinity are expected to affect the metabolism of young squid and we tested their effects on growth during the embryonic and post-hatching phase, based on measurements of growth increments in statoliths of juveniles and adults, using generalized additive models. There was no evidence that statolith increments representing early growth become unreadable in adult statoliths. Variability in the statolith size at hatching was weakly but significantly related to the variables in the model. On the other hand, the effects on statolith growth of both sea surface temperature and of sea bottom temperature were significant during early post-hatching life. Thicker increments are deposited in the statoliths of squid living under higher temperatures, which results in summer hatchers having larger statoliths at the age of 90 days. Inspection of the statolith accretion pattern, using a piecewise linear regression method, revealed an ontogenetic shift in increment width, which may be an indication of the age of transition from paralarva to juvenile. On this basis, it is suggested that the planktonic stage lasts 60 or 90 days, depending on whether the paralarvae lived at higher (.158C) or lower (,158C) sea surface temperatures. The life strategy under warmer conditions potentially favours survival by reducing the duration of the vulnerable planktonic phase. (2006) Oceanography and fisheries of the Canary Current/Iberian region of the eastern North Atlantic. In Brink K.H. and Robinson A.R. (eds) The sea. Volume 14B: the global coastol ocean. Cambridge, MA: Harvard University Press, pp. 877-931. Arkhipkin A.I. (2004) Diversity in growth and longevity in short-lived animals: squid of the suborder Oegopsina. Marine and Freshwater Research 55, 341-355. Arkhipkin A.I. (2005) Statoliths as 'black boxes' (life recorders) in squid. Marine and Freshwater Research 56, 573 -583.
Turkish Journal of Fisheries and Aquatic Sciences, 2005
Loligo vulgaris Lamarck, 1798 spawns monocyclic and egg-laying occurs in separate batches during the spawning period (Rocha et al., 2001). Egg capsules of L. vulgaris are laid on the underside of rocky overhangs, on branched sessile organisms (Boletzky, 1998) or on fishing lines (Villenueva, 2000; Villanueva et al., 2003; see also “Materials and methods” of present study) and hang down in the water. The egg masses comprise dozens to hundreds of finger-like egg capsules, 60-160 mm in length, and each capsule containing 50-130 eggs of 1.92-2.88 mm in diameter (Mangold-Wirz, 1963; Worms, 1983; Marthy and Aroles, 1987; Martins, 2001; en, 2003, 2004). Temperature is the main factor that regulates the length of embryonic development in cephalopods (Boletzky, 1987). Embryogenesis of L. vulgaris depends on the experimental water temperature, ranging from a few weeks to a few months (Naef, 1928; Jecklin, 1934; Mangold-Wirz, 1963; Boletzky, 1974; 1987; en, 2003; 2004). Villanueva et al. (2003...
Reviews in Fish Biology …, 2007
Statolith size and growth was used to determine the influence of abiotic factors on the growth of Loligo vulgaris and Sepioteuthis australis embryos. Recently spawned egg masses collected from the field were incubated in the laboratory under different levels of light intensity, photoperiod, or short periods of low salinity (30&). Double tetracycline staining was used to follow statolith growth. In L. vulgaris constant light conditions produced significantly slower growth in the embryonic statoliths and embryos held at summer photoperiod had slower statolith growth than those held at winter photoperiods. However once they hatched out there was no evidence that photoperiod affected statolith growth. After hatching, in all photoperiods statolith growth rates decreased in comparison with late embryonic rates. In S. australis embryos, differences between the high and medium light intensities for summer and intermediate photoperiods were found, suggesting that under summer incubation temperature, longer daylengths at medium light intensity favoured higher statolith growth for this species. In comparison to controls, slower statolith growth in S. australis embryos due to low salinity only occurred when exposed for 72 h. Comparison with previous studies indicates that temperature seems to be the main abiotic factor influencing statolith growth during early stages, however, interactions among all abiotic factors needs to be determined as well as the unknown influence of other isolated factors, e.g., oxygen concentration within the egg mass.
Growth strategies in the squid Loligo vulgaris from Portuguese waters
Marine Biology Research, 2007
The growth of the European squid Loligo vulgaris in northwest Portuguese waters is described and the influences of gender and hatching season analysed, based on statolith readings from individuals of a wide range of sizes. Male and female growth follows different models, males attaining a higher length-at-age than females. Males display increasing growth rates irrespective of the hatching season, but the length-at-age is higher in animals hatched during the warm season. Females may exhibit asymptotic growth or not, depending upon the environmental conditions to which they are exposed through their life cycle. Although growth rates after hatching are lower in females hatched during the cold season, favourable feeding and temperature conditions during the following spring and summer months contribute not only to increase growth rates but also to delay sexual maturation. The higher length-at-age of squid hatching in the warm season, observed in both genders, provides evidence that the temperature close to hatching has a significant impact on the size of juveniles and subadults. However, there is also strong evidence that throughout their life, environmental conditions continue to play an important role in growth rates and in defining the shape of growth.
Effect of temperature on statolith growth of the European squid Loligo vulgaris during early life
Marine Biology, 2000
Over the past decade, statolith interpretation has resulted in a major advance in our knowledge of squid population-dynamics, but the way in which environmental conditions aect the statolith increment-deposition ratio remains virtually unknown. The object of the present study was to determine the eect of temperature on this process, using tetracycline marks to validate statolith growth in Loligo vulgaris Lamarck, 1798 under rearing conditions equivalent to severe winter (11°C) and summer (19°C) temperature regimes. Tetracycline marking was performed every 10 d (at 10, 20, 30, 40, 50 and 60 d of age). The newly hatched squid paralarvae were slightly smaller in summer than those hatched in winter. Survival rates were similar in both cultures, but growth rates (wet mass) of summer squids were double those in winter. At hatching, statoliths were already longer in the summer squids, and growth rates were 2% d )1 as opposed to 0.9% d )1 for winter statoliths. For the dorsal dome area of the statolith, where more increment counts were made, statolith growth was of 3.25 lm d )1 in summer, and daily increment deposition was con®rmed in 87% of the statoliths. The slow growth of statoliths at winter temperatures yielded a mean growth of 1.1 lm d )1 ± insucient to discern the increments using light microscopy. Subsequent SEM observation enabled only 21% of the winter statoliths to be read; these also indicated a deposition rate of one increment d )1 . Since the life span of L. vulgaris is '1 yr, squids will experience at least one winter during their life cycle, and this might be visible on the statolith.
Embryonic stages of the Patagonian squid Loligo gahi (Mollusca: Cephalopoda)
Veliger -Berkeley-
The embryonic development of Loligo gahi was observed from 4-day-old eggs to natural hatching. Egg strands spawned in the Valparaíso Bay, Chile, were transported to an open system tank for incubation. Temperatures ranged from 12.9°C to 13.5°C, salinities from 34%c to 35%c, and the photoperiod was 12L:12D. The period from spawning to hatching ranged from 30-35 days. The diameter of individual eggs ranged from 2.5-3.2 mm, and the dorsal mantle length of hatchlings varied from 2.6-3.1 mm. The pattern of chronological appearance of organs was quite similar to loliginid species prevíously examined (Loligo aff. gahi, Loligo bleekeri, Loligo pealei, Loligo vulgaris reynaudii, and Loligo forbesii). However, L. gahi had a different (faster) development time and a smaller embryo and hatchling size than L. bleekeri (Japan) and L. forbesii (eastern Atlantic Ocean). Differences (heterochronies) among species are discussed. Allometric growth of embryonic development in L. gahi using seven morphometric parameters was undertaken.