Castro, J.J.

Couce-Montero, L.

Espino-Ruano, A.

Guerra-Marrero, A.

Jimenez-Alvarado, D.

Perales-Raya, C. (Catalina)

English

Repositorio Institucional Digital del IEO

Age validation in early stages of Sepia officinalis and its application to age estimation of Sepia speciesAiram Guerra-Marrero1*, Lorena Couce-Montero1, Ana Espino-Ruano1, David Jiménez-Alvarado1, José J. Castro1 and Catalina Perales-Raya2Born Death~ 12 monthsBackgroundBackgroundOctopus vulgaris Octopus mayaHernández-López et al., 1999Peráles-Raya et al.,2000, 2014Villegas-Bárcenas et al. 2014Sepia officinalisLishchenko et al, 2018 Aim“Validate the growth marks in early stagesof Sepia officinalis beaks that allow us toestimate the real age in Sepia species”Experiment designCulture at 21º CFeed ad libitumSacrifices day by day, until day 5. Then every 5 days or by natural death.Culture at 18º CFeed ad libitumSacrifices day by day, until day 5. Then every 5 days or by natural death.Experiment 1 Experiment 2The experiments were repeated twice in order to standardize themethodology.Culture~40 μm LRL~ 5.5 mm DMLv29 individuals a 18ºC73 individuals a 21ºCMax age  31 daysPhase Iv47 individuals a 21ºCMax age  20 daysPhase IIFigure 1. Anterior region (lateral view) of the lower beak : Location of the main regions(R: rostrum, H: Hood, S: Developing shoulder); the arrow indicates the first incrementand the white segment indicates the width of the reading area (scale bar= 100 μm).Hatching day 10 days 20 daysReproducibilityThe increments were counted by two readers, both reading each beak two times . When counts of both readers coincided twice, the reading was taken as valid. Coefficient of variation (CV) (Perales-Raya, 2018) was calculated to determinethe precision (reproducibility) of the counts for each reader in each individual :   To avoid any bias by age groups, the CVs were averaged for each age group, and when CV<7.6% were taken as valid (Campana et al., 2001).ReproducibilityMean reading precision (CV) from the beak reading was 2.95 ± 5.98 %for all individuals. CV in age reading in sepia cultured at 21ºC (n=120)was 3.26 ± 6.75%, and 2.01 ± 2.47% for individual cultured at 18ºC(n=25).The methodology is validated1 increment  1 day of lifeTable 1. Results of: (a) lineal regression analysis for the number of growth increments (NI), the age (days from hatching) and width of the reading area (WRA) by rearing temperature (21º or 18ºC) in the Phase I. (b) General lineal model (GLM) coefficients; ***p<0.001 Regressions are divided by phasesFigure 2. Growth of cultured newly hatched Sepia officinalis: (A) Relationshipbetween the mean number of increments counted in the lower beak and thereal age; (B) Dorsal Mantle Length and the real age; (C) Lower beak growth (widthof the reading area; see Fig. 1) with real age. Data grouped by temperature in thedifferent phases.The rostrum was the best region of the beak where the sequence of growth increments was the most visible. The hatching mark was clearly identified Conclusions of Age validationThe high coincidence among readings indicates the reproducibility of readings of the rostral area in beaks of Sepia officinalis.Daily deposition was validated in the rostral area of lower beaks from 0 to31 days.No differences were observed in the daily deposition and the growthreading area at different temperatures (p=0,777).Applications- Sepia berthelotiA total of 1123 individuals of Sepia bertheloti were collected from June 2018 to January 2020. They were caught by commercial trawlers operating in Morocco (552 individuals) and Guinea-Bissau (571 individuals). Figure 3. Sampling areas (FAO Fishing Areas) where the commercialtrawlers caught Sepia bertheloti in Morocco (Tangier zone) (FAO 1.11)and Guinea-Bissau (FAO 3.13). Exclusive Economic Zone (EZZ) forMorocco (Tangier zone) and Guinea-Bissau in the FAO Fishing areasare shadedA subsample of 78 individuals from Morocco and 128 from Guinea-Bissau were analysed. The subsample was randomly performed  by categorizing the individuals by size range for both sexes every 5 mm of Dorsal Mantle Length (DML).The methodology used for processing the Lower beaks was that describedby Perales-Raya et al. (2010).Once the beaks were processed, they were analysed using a Nikon Microscope Multizoom AZ100 with and UV-epiillumination attachment (vertical reflected light). ResultsCuttlefishes from Guinea-Bissau showed an estimated agebetween 94 (72 mm DML) and 433 days (160 mm DML), witha mean age of 231.19 days. Estimated age for individuals fromMorocco ranged from 111 (60 mm DML) to 419 days (140 mmDML), with a mean value of 220.53 days.Figure 4. Appearance of growth increments in the lower beak section of Sepia bertheloti (300x).Guinea-BissauMoroccoAge (months)Dorsal MantleLength(mm)Dorsal Mantle Length (mm)Age (months)Table 2. Dorsal mantle length growth-rates for each age-class of Sepia bertheloti females and males from Morocco and Guinea-Bissau. G: instantaneous relative growth rate (% DML d-1); AGR: absolute growth rate (mm d-1). X̄: average; SD: standard deviation.ConclusionsAssuming the initial hypothesis of 1 increment – 1 day of life, according to the first experiment in Sepia officinalis, a maximum life expectancy of 433 days was obtained for Guinea-Bissau and 419 days for Morocco.Specimens from Guinea-Bissau showed larger sizes than individuals fromMorocco for the same age classes.The differences in growth patterns seem a priori to be related to the different oceanographic conditions of both areas (individuals from Guinea Bissau grow faster due to its warmer waters).Age validation in early stages of Sepia officinalis and its application to age estimation of Sepia speciesAiram Guerra-Marrero1*, Lorena Couce-Montero1, Ana Espino-Ruano1, David Jiménez-Alvarado1, José J. Castro1 and Catalina Perales-Raya2Thanks for you attention!

Age validation in early stages of Sepia officinalis and its application to age estimation of Sepia species

Perales-Raya, Catalina

Digital.CSIC

http://www.repositorio.ieo.es/e-ieo/bitstream/10508/16178/1/ISMS-198_Guerra_Marrero_SepiaOfficinalis_ISMS2022.pdf

Age validation in early stages of Sepia officinalis and its application to age estimation of Sepia species

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