Seasonal Movement Patterns of the Bigfin Reef Squid Sepioteuthis lessoniana Predicted Using Statolith δ18O Values

Abstract

Sepioteuthis lessoniana is a widely distributed neritic squid in the Indo-Pacific Ocean. It is an important species in fisheries, but species management is difficult because of inadequate information regarding its life history. The daily growth and δ 18 O values from the core to the edge of statoliths of S. lessoniana collected in northern Taiwan were analyzed to predict the experienced temperature history along with ontogenetic stages. The probability of occurrence in a given area at each life stage in three seasonal groups was determined using salinity values, deduced and measured temperatures, and the known ecology of S. lessoniana. The results showed that ontogenetic variation in the statolith δ 18 O values in S. lessoniana reflected the seasonal temperature fluctuation observed in Taiwanese waters, which indicated the reliability of the prediction method. Complex and diverse distribution and movement patterns were observed in the three seasonal groups. The results also indicated the importance of the waters near the coast of northeastern Taiwan as a spawning ground. Based on a model prediction, the distribution of S. lessoniana is likely associated with water temperature and current. A potential migration route from the Penghu Islands to northeastern Taiwan suggests a high level of population connectivity in S. lessoniana in Taiwan. This study provides information on the spatial and vertical distribution of S. lessoniana at various ontogenetic stages, which is essential for resource management and conservation of this commercial species.

A checklist of cephalopods from continental shelf of Sarawak, Malaysian Borneo

“…They are caught in large numbers either as a targeted species or as by-catch products from the commercial fishery industries (Carpenter and Niem 1998). Interestingly, the bigfin squid S. lessoniana was previously reported to inhabit subtidal areas to a depth of 45 m (Alexander et al 2015) and 100 m (Chiang et al 2020) while in contrast, during the present study, this species was found at two stations in the Sarawak EEZ at a depth of 20 m and 140 m, respectively. The most commonly distributed species from Family Octopodidae was A. marginatus which was found at 19 out of the 153 stations sampled, this was followed by A. rex (4 stations), Cistopus sp.…”

Phylogenetic and morphological characteristics of Sepioteuthis lessoniana (Cephalopoda: Loliginidae) in the South China Sea and Andaman Sea

“…This study found 2 intermediate individuals of S. lessoniana. One possible reason for the intermediate individuals in this study is that the S. lessoniana small-size form male mated with the S. lessoniana medium-size form female due to the mitochondrial DNA (mtDNA) inherited from the female, supported with a previous study which showed that mature S. lessoniana moved seasonally for mating and spawning [22]. As a result, the small-and medium-size forms might meet and mate in the South China Sea.…”

“…The TSRT and ASRT of both forms had triangular teeth, whereas the average number of TSRT was 20.7 (range: [16][17][18][19][20][21][22][23][24][25] in the small-size form and 16.7 (range: 14-30) in the medium-size form. For the number of ASRT, the average number was 25.9 (range: 19-34) in the small-size form and 21.3 (range: 18-28) in the medium-size form.…”

Bacterial Dynamics in the Accessory Nidamental Gland of <i>Sepioteuthis lessoniana</i> throughout Maturation

“…Between April and October in Taiwan, S. lessoniana swims in groups to the shore for spawning. The population structure of S. lessoniana in Taiwan has been investigated using life history parameters, statolith geochemical signatures, and genetic analyses ( Ching et al , 2019 ; Chiang et al , 2020 ), and one predominant taxon was found in the water of northeastern Taiwan.…”