The paralarval stage as key to predicting squid catch: Hints from a process-based model

Bruggeman, Jorn; Jacobs, Zoe; Popova, Ekaterina; Sauer, W. H. H.; Gornall, Jessica; Brewin, Robert J. W.; Roberts, Michael J.

doi:10.1016/j.dsr2.2022.105123

Cited by 2 publications

(1 citation statement)

References 78 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…That along with predation and high dependence on environmental conditions for recruitment success to the adult population can result in wide inter-annual fluctuations in abundance (Boyle and Rodhouse, 2005). As expected, the Paralarval phase is increasingly seen as being important in fisheries modelling (Bruggeman et al, 2022).…”

Section: Discussionsupporting

confidence: 56%

Cephalopod ontogeny and life cycle patterns

Vidal¹,

Shea

2023

Front. Mar. Sci.

View full text Add to dashboard Cite

Life cycle definitions provide the background for conceptualizing meaningful questions to address the mechanisms that generate different life cycle patterns. This review provides explicit definitions and explanations of the steps in a cephalopod life cycle, from fertilization to death. Each large step, or phase, is characterized by a particular developmental process and morphology. Each phase is composed of smaller developmentally distinct steps, or stages. The cephalopod life cycle is comprised of all or some of the following phases: Embryonic, Paralarval, Juvenile, Subadult, Adult and Senescent, and each life cycle is taxon-specific. All cephalopods have direct development and maintain a consistent body plan throughout ontogeny (i.e., no true larval phase and no metamorphosis). Most cephalopods have a life cycle marked by a long early life and a short adult life followed by senescence. Cephalopods have two developmental modes: they produce either small planktonic hatchlings as paralarvae, or large hatchlings as juveniles. All cephalopods go through a Hatchling stage soon after eclosion during which they rely on two modes of nutrition: endogenous (yolk) and exogenous (prey). Many cephalopods with planktonic paralarvae will become benthic early in their life cycle during their Settlement stage or remain pelagic during their Metapelagic stage. Juvenile growth is fast and ontogenetic changes (outside of gonadal maturation) generally cease at the end of the Juvenile phase. The Subadult phase begins when the definitive adult morphology (except for size and body proportions) is acquired (e.g., full complement of photophores). Sexual organs undergo most of their development during the Subadult phase. The Adult phase starts with spawning competency and concludes when gonads are spent. The Senescent phase begins with spent gonads and ends with death. Using this new terminology, we examine the patterns of cephalopod life cycles and find that there are four main patterns based on the presence of a Paralarval phase and the habitat occupied by each phase: Holopelagic (all phases are pelagic), Holobenthic (all phases are benthic), Merobenthic and Meropelagic (phases alternate between benthic and pelagic environments). In these two last patterns, the main difference is the presence of a Paralarval phase in Merobenthic species. The definitions and terminology proposed here provide a unifying framework for future ecological, evolutionary and life cycles research on cephalopods.

show abstract

Section: Discussionsupporting

confidence: 56%

Cephalopod ontogeny and life cycle patterns

Vidal¹,

Shea

2023

Front. Mar. Sci.

View full text Add to dashboard Cite

show abstract

Impact of environmental conditions on English Channel long-finned squid (Loligo spp.) recruitment strength and spatial location

Marcout,

Foucher,

Pierce

et al. 2024

Front. Mar. Sci.

View full text Add to dashboard Cite

The English Channel has the highest long-finned squid landings in the Northeast Atlantic, making squid one of the most valuable resources exploited by demersal fisheries operating in this area. This resource consists of two short-lived long-finned squid species: Loligo forbesii and L. vulgaris, which have a similar appearance (they are not distinguished by fishers) but differ in the timing of their life cycle: in L. forbesii, the recruitment peak occurs in July while in L. vulgaris recruitment peak occurs in November. The abundance and distribution of cephalopod species, such as Loligo spp., depends on favourable environmental conditions to support growth, reproduction and successful recruitment. This study investigated the role of several environmental variables (bottom temperature, salinity, current velocity, phosphate and chlorophyll concentrations) on recruitment biomass (in July for L. forbesii and November for L. vulgaris), as based on environmental data for pre-recruitment period from the Copernicus Marine Service and commercial catches of French bottom trawlers during the recruitment period over the years 2000 to 2021. To account for non-linear relationship between environmental descriptors and the biological response, General Additive Models (GAM) were fitted to the data. Separate models were obtained to forecast L. vulgaris and L. forbesii biomass indices during their respective recruitment periods. These models explain a high percentage of variation in biomass indices (65.8% for L. forbesii and 56.7% for L. vulgaris) and may be suitable to forecast the abundance (in terms of biomass) and spatial distribution of the resource. Such forecasts are desirable tools to guide fishery managers. Since these models can be fitted shortly before the start of the fishing season, their routine implementation would take place in real-time fishery management (as promoted by fishery scientists dealing with short-lived species).

show abstract

The paralarval stage as key to predicting squid catch: Hints from a process-based model

Cited by 2 publications

References 78 publications

Cephalopod ontogeny and life cycle patterns

Cephalopod ontogeny and life cycle patterns

Impact of environmental conditions on English Channel long-finned squid (Loligo spp.) recruitment strength and spatial location

Contact Info

Product

Resources

About