Evidence map›Paper›PMID 42219221›Full record

ArticleJournal of fish biology2026

Life-history traits of the blackbelly lanternshark Etmopterus lucifer off the Pacific coast of northeastern Japan.

Arata Hirahara, Mai Suzaki, Yoji Narimatsu, Orio Yamamura

Abstract read
In one paragraph

Article in Journal of fish biology, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

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0citing papers in PubMed
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1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

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3 · Its place in the literature

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0 citing papers in PubMed.

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4 · The record

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PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

4 authors.

Arata HiraharaGraduate School of Fisheries Sciences Hokkaido University, Hakodate, Japan.ORCID https://orcid.org/0009-0007-8508-2656
Mai SuzakiGraduate School of Fisheries Sciences Hokkaido University, Hakodate, Japan.
Yoji NarimatsuDemersal Fish Resources Division, Fisheries Stock Assessment Center, Fisheries Resources Institute, Japan Fisheries Research and Education Agency, Hachinohe, Japan.
Orio YamamuraGraduate School of Fisheries Sciences Hokkaido University, Hakodate, Japan.ORCID https://orcid.org/0000-0002-8887-2043

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

The growth, maturity, reproductive biology and life cycle of the blackbelly lanternshark Etmopterus lucifer, a small deep-sea species with an extremely high population density off the Pacific coast of northeastern Honshu, Japan, were examined. Age was estimated by counting growth bands in cross-sections of the second dorsal fin spine and validated through marginal increment ratio (MIR) analysis, which revealed an apparent decrease in June-July values compared to other months, indicating that growth bands are formed annually. The females examined were 0-13 years old and the males were 0-10 years old. The size and age at 50% maturity were 344 mm TL and 6.53 years for females, and 288 mm TL and 3.82 years for males, respectively. Although the blackbelly lanternshark exhibited a high von Bertalanffy growth coefficient and early age at maturity compared to other squalids, its fecundity was relatively low, with an average of 8.6 ripe oocytes per female. These results indicate that the blackbelly lanternshark is an r-selected life-history species with a high growth coefficient and early maturity that is achieved by limiting its asymptotic length. The mating season was inferred to be in early summer, corresponding to a decline in the male gonadosomatic index (GSI). In contrast, based on increases in female GSI values and oocyte diameters, ovulation likely occurs from autumn to spring. The similarity in oocyte diameters in the resting and maturing stages, combined with an intermediate uterine state between mature and gravid, indicates that this species does not achieve immediate postpartum gestation, instead requiring a prolonged interval for ovarian maturation and uterine contraction before the next reproductive cycle. Therefore, although the blackbelly lanternshark has relatively low fecundity within one reproductive season, this species has fast growth and maturity, which may contribute to its prosperity in the study region.

Indexed as

Life History TraitsSharksAnimalsFemaleFertilityJapanMalePacific OceanReproductionSeasonsSexual Maturationage and growthdeep‐sea sharklife cyclematurityreproductive biologySqualiformes

Identifiers

PMID42219221
PMCPMC13521718

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.