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Vol. 63, 2024
(update: 2024.1.26)
Age and Growth of the Indian
Squid, Uroteuthis duvaucelii:
Analysis of Statolith Microstructure and Length Frequency Data
Jessica
M. Legaspi1,* , Annabelle G.C. del
Norte-Campos2, and Wilfredo L. Campos3,*
doi:-
1Kuroshio
Science Program, Graduate School of Integrated Arts and Sciences, Kochi
University, 200 Otsu, Monobe, Nankoku City, Kochi 783-8502, Japan.
*Correspondence: E-mail: jessicamanagalegaspi@gmail.com (Legaspi)
2Marine Bio Lab, Division of Biological Sciences,
College of Arts and Sciences, University of the Philippines Visayas,
Maty, Miagao, 5023, Iloilo, Philippines. E-mail: adcampos@up.edu.ph
(del Norte-Campos)
3OceanBio Lab, Division of Biological Sciences,
College of Arts and Sciences, University of the Philippines Visayas,
Maty, Miagao, 5023, Iloilo, Philippines. *Correspondence: E-mail:
wlcampos1@up.edu.ph (Campos)
(Received 12 September 2023 /
Accepted 6 February 2024 / Published -- 2024)
Communicated by Chien-Hsiang Lin
Understanding the age and
development of a species provides knowledge about its longevity and
growth, which are crucial in assessing its life history to maintain the
sustainability of its fisheries. Over 3000 samples of Uroteuthis duvaucelii were
collected from trawl catches off Concepcion, Iloilo, Western Visayas,
Philippines, from April 2018 to September 2019. Daily rings in the
statolith were used to determine the age. The estimated age ranged from
73 to 154 days old, corresponding to sizes of 3.1 to 28.1 cm mantle
length. The presence of small individuals (~4 cm) throughout the year
indicate continuous spawning of this species. Growth curve patterns of U. duvaucelii were examined using
two techniques: growth from size-at-age data (statolith increments) and
growth generated from length-frequency data using the ELEFAN software
package. Both methods yielded results that were remarkably different
from one another. The growth curve generated from length frequency
analysis produced an asymptotic growth. In contrast, size-at-age data
(mantle length-age relationship) revealed that U. duvaucelii does not grow
asymptotically. The growth of this tropical squid is best fitted with
exponential growth, exhibiting a continuous rapid growth and short
lifespan, a prominent characteristic observed in neritic species of
squids. This work provides evidence that asymptotic growth is not
applicable for the tropical squid species in the Visayan Sea,
Philippines.
Key words: Cephalopods, Growth, Age,
Statolith, Length Frequency
Citation: Legaspi JM, del Norte-Campos
AGC, Campos WL. 2024. Age and growth of the Indian squid, Uroteuthis duvaucelii: analysis of
statolith microstructure and length frequency data. Zool Stud 63:12.
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