scholarly journals Novel insights into early life stages of finned octopods (Octopoda: Cirrata)

2021 ◽  
Vol 140 (1) ◽  
Author(s):  
Alexander Ziegler ◽  
Abigail Miller ◽  
Nina Nagelmann
Keyword(s):  
Deep Sea ◽  
Early Life ◽  
Imaging Techniques ◽  
Three Dimensional ◽  
Life Stages ◽  
Early Life Stages ◽  
Egg Capsules ◽  
First Time ◽  
Capsule Size ◽  
Combined Data

AbstractThe finned or dumbo octopods (Octopoda: Cirrata) constitute a cephalopod (Mollusca: Cephalopoda) taxon almost exclusively comprising organisms that inhabit the deep-sea. This renders studying the general biology of adult cirrate specimens a difficult task, but even more so when it comes to gathering knowledge on their early life stages. During his comprehensive research exploits on cephalopod development, the late Sigurd von Boletzky (1942–2020) also sought to shed light on specific adaptations that eggs and embryos of these enigmatic deep-sea octopods might show. Based on his seminal work, the present article sets out to provide additional data on a broad range of early cirrate life stages, including egg capsules without any obvious embryonic stage as well as those containing embryos. These previously unreported specimens obtained from museum collections were analyzed using conventional morphological as well as modern three-dimensional imaging techniques. The present overview includes specimens from four of the five oceans, i.e., the Atlantic, Pacific, Indian, and Southern Ocean. Based on information on cirrate ovum, chorion, and egg capsule size as well as shape gathered from the literature, an attempt is made here for the first time to identify von Boletzky's as well as the specimens introduced here down to at least genus level. The combined data provide novel insights into early life stages of finned octopods, aiming to continue von Boletzky's legacy with regard to developmental research on a still largely enigmatic taxon of extant deep-sea cephalopods.

Early life stages, growth, and reproduction of spring-spawning ciscoes (Coregonus artedii) in Lac des Écorces, Quebec

1991 ◽  
Vol 69 (6) ◽  
pp. 1644-1652 ◽  
Author(s):  
Michel Hénault ◽  
Réjean Fortin
Keyword(s):  
Environmental Conditions ◽  
Early Life ◽  
Liver Weight ◽  
Life Stages ◽  
Early Life Stages ◽  
Total Length ◽  
Males And Females ◽  
Coregonus Artedii ◽  
Egg Diameter ◽  
First Time

The biological characteristics of an allopatric population of spring-spawning ciscoes, an extremely rare ecotype, were studied at Lac des Écorces (southwestern Quebec). Environmental conditions during the early life stages are marginal for the species; the eggs are deposited in the deeper section (>20 m) of the lake and the first larva was caught on 30 July. Epilimnetic temperatures were then near the upper lethal threshold for fall cisco larvae. Lac des Écorces ciscoes are very small at the end of their 1st year of life (mean total length 58 mm). They more than double in length during their 2nd year (mean total length 161 mm). Growth thereafter, longevity, fecundity, and egg diameter are within the observed ranges for the species. Spawning occurs from mid-May to early June. Males and females spawn for the first time at age 3. The best predictor of fecundity is liver weight. Gametogenesis occurs under environmental conditions different from those encountered by fall-spawning salmonids. Seasonal changes in the gonadosomatic and hepatosomatic indexes are discussed in terms of temperature, photoperiod, and hormonal influences.

Evolutionary individual-based model for the recruitment of anchovy (Engraulis capensis) in the southern Benguela

2002 ◽  
Vol 59 (5) ◽  
pp. 910-922 ◽  
Author(s):  
Christian Mullon ◽  
Philippe Cury ◽  
Pierrick Penven
Keyword(s):  
Early Life ◽  
Three Dimensional ◽  
Population Level ◽  
Threshold Temperature ◽  
Environmental Constraints ◽  
Life Stages ◽  
Early Life Stages ◽  
Individual Based Model ◽  
Individual Level ◽  
The Individual

Evolutionary simulations are developed to explore environmental constraints that select observed spatial and temporal spawning patterns for anchovy (Engraulis capensis) in the southern Benguela. They couple a realistic three-dimensional hydrodynamic model with an individual-based model in which an evolutionary-based reproductive strategy for adult fish and a passive transport for early life stages are implemented. The evolutionary success of spawning is quantified when patterns at the population level emerge after many generations from constraints at the individual level through a selective process. As a result, several self-sustaining populations are identified considering different sets of selective constraints. Simulated spawning patterns better match the observed mean spawning pattern when two selective environmental constraints are associated: a threshold temperature of 14°C, above which the development of early life stages is ensured, and the avoidance of offshore currents that constitute a loss of spawning products. Simulated recruitment patterns are more realistic when considering the constraint of reaching the nursery area. This modeling experience can help to identify, temporally and spatially, environmental factors important for fish recruitment and to establish a hierarchy of these factors. The probable coexistence in nature of several self-sustaining populations of pelagic fishes is shown to be important for recruitment studies.

Natural and anthropogenic effects on the early life stages of European anchovy in one of its essential fish habitats, the Guadalquivir estuary

2019 ◽  
Vol 617-618 ◽  
pp. 67-79 ◽  
Author(s):  
GF de Carvalho-Souza ◽  
E González-Ortegón ◽  
F Baldó ◽  
C Vilas ◽  
P Drake ◽  
...  
Keyword(s):  
Early Life ◽  
Anthropogenic Effects ◽  
Life Stages ◽  
Early Life Stages ◽  
European Anchovy ◽  
Guadalquivir Estuary ◽  
Fish Habitats

Incubation Temperature Influences the Duration of Egg Hatching and Early Development in the Boreal Digging Frog, Kaloula Borealis

2020 ◽  
Vol 3 (1) ◽  
pp. ACCEPTED
Author(s):  
Rho-Jeong Rae
Keyword(s):  
Water Temperature ◽  
Early Life ◽  
Rainy Season ◽  
Incubation Temperature ◽  
Life Stages ◽  
Early Life Stages ◽  
Egg Hatching ◽  
Significant Difference ◽  
The Mean ◽  
Hatching Rates

This study investigated the boreal digging frog, Kaloula borealis, to determine the egg hatching period and whether the hatching period is affected by incubation temperature. The results of this study showed that all the eggs hatched within 48 h after spawning, with 28.1% (±10.8, n=52) hatching within 24 h and 99.9% (±0.23, n=49) within 48 h after spawning. A significant difference was noted in the mean hatching proportion of tadpoles at different water temperatures. The mean hatching rates between 15 and 24 h after spawning was higher at a water temperature of 21.1 (±0.2) °C than at 24.1 (±0.2) °C. These results suggest that incubation temperature affected the early life stages of the boreal digging frog, since they spawn in ponds or puddles that form during the rainy season.

First Records and Descriptions of Early Life Stages of Cephalopods from Rapa Nui (Easter Island) and the Nearby Apolo Seamount

2019 ◽  
Vol 73 (1) ◽  
pp. 163 ◽  
Author(s):  
Sergio A. Carrasco ◽  
Erika Meerhoff ◽  
Beatriz Yannicelly ◽  
Christian M. Ibáñez
Keyword(s):  
Early Life ◽  
Easter Island ◽  
Life Stages ◽  
Early Life Stages ◽  
Rapa Nui
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