The food source of Sargasso Sea leptocephali

Miller, Michael J.; Hanel, Reinhold; Feunteun, Éric; Tsukamoto, Katsumi

doi:10.1007/s00227-020-3662-6

Cited by 16 publications

(20 citation statements)

References 147 publications

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“…Thus, leptocephali likely feed on the nutrient-rich soft marine snow particles composed of substances derived from various organisms, which have been decomposed by bacteria 67 . Our results are consistent with the low trophic position of the natural food of leptocephali estimated by stable isotopic analysis of the nitrogen located between primary producers and primary consumers 23 .…”

Section: Discussionsupporting

confidence: 90%

“…Artificially cultured Japanese eel survived by eating small POM (53 and 25 µm) from seawater 22 ; however, they died upon eating large POM (> 350 µm), strongly suggesting that relatively large zooplankton and/or phytoplankton, specifically those with hard or sharp bodies, seriously damaged the digestive organs of leptocephali. Smaller particles may therefore be of importance for these larvae 16 , and this corresponds with the food source known as marine snow detrital-type particles 23 . Small spherical particles (2–40 µm in diameter) of marine snow comprising polysaccharides and proteins within the aggregate is a common finding in both the gut contents of anguilliform leptocephali 15 , 16 , 23 , 55 and environmental water 16 , suggesting that marine snow particles originating from phytoplankton and cyanobacteria are a food source for the leptocephali 16 .…”

Section: Discussionmentioning

confidence: 99%

“…Smaller particles may therefore be of importance for these larvae 16 , and this corresponds with the food source known as marine snow detrital-type particles 23 . Small spherical particles (2–40 µm in diameter) of marine snow comprising polysaccharides and proteins within the aggregate is a common finding in both the gut contents of anguilliform leptocephali 15 , 16 , 23 , 55 and environmental water 16 , suggesting that marine snow particles originating from phytoplankton and cyanobacteria are a food source for the leptocephali 16 . Thus, food sources of eel larvae in the marine environment are assumed to be small or soft marine snow particles in POM 56 .…”

Section: Discussionmentioning

confidence: 99%

“…Further, analyses of fatty acids and lipids 17 , 18 and stable isotopes 20 – 22 , indicate that leptocephali feed on POM originating from organisms at lower trophic levels 13 – 16 , 19 – 22 . These observations suggest that marine snow detrital-type particles in the POM are a food source 23 .…”

Section: Introductionmentioning

confidence: 88%

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18S rRNA gene sequences of leptocephalus gut contents, particulate organic matter, and biological oceanographic conditions in the western North Pacific

Watanabe

Nagai

Kawakami³

et al. 2021

Sci Rep

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Eel larvae apparently feed on marine snow, but many aspects of their feeding ecology remain unknown. The eukaryotic 18S rRNA gene sequence compositions in the gut contents of four taxa of anguilliform eel larvae were compared with the sequence compositions of vertically sampled seawater particulate organic matter (POM) in the oligotrophic western North Pacific Ocean. Both gut contents and POM were mainly composed of dinoflagellates as well as other phytoplankton (cryptophytes and diatoms) and zooplankton (ciliophoran and copepod) sequences. Gut contents also contained cryptophyte and ciliophoran genera and a few other taxa. Dinoflagellates (family Gymnodiniaceae) may be an important food source and these phytoplankton were predominant in gut contents and POM as evidenced by DNA analysis and phytoplankton cell counting. The compositions of the gut contents were not specific to the species of eel larvae or the different sampling areas, and they were most similar to POM at the chlorophyll maximum in the upper part of the thermocline (mean depth: 112 m). Our results are consistent with eel larvae feeding on marine snow at a low trophic level, and feeding may frequently occur in the chlorophyll maximum in the western North Pacific.

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Section: Discussionsupporting

confidence: 90%

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 88%

See 2 more Smart Citations

18S rRNA gene sequences of leptocephalus gut contents, particulate organic matter, and biological oceanographic conditions in the western North Pacific

Watanabe

Nagai

Kawakami³

et al. 2021

Sci Rep

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“…The long, ribbon‐shaped leptocephali have a body composition and feeding behaviors that are different from other teleost larvae. Unlike most larval fishes, which are visual feeders with a diet of plankton, leptocephali appear to have a diet based on mucilaginous “marine snow” derived from a wide array of sources including discarded mucus houses of appendicularians and other gelatinous materials (Chow et al, 2019; Miller et al, 2020). At hatching, leptocephali are morphologically primitive larvae that have not yet developed jaws or digestive tracts, eyes, and other characteristics necessary for location and consumption of food (Halstead, 2019).…”

Section: Introductionmentioning

confidence: 99%

Lipid Composition and Utilization in Early Stage Leptocephalus Larvae of Bonefish (Albula vulpes)

Mejri

Adams

Shenker

et al. 2020

Lipids

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In order to encourage the survival of both captive and wild populations of bonefish (Albula vulpes), a deeper understanding of the species' early developmental characteristics is necessary. During ontogenesis, bonefish utilize lipids as a source of energy before the start of exogenous feeding. The goal of this study is to gain insight into the energetic needs of bonefish leptocephalus larvae in the post‐hatch larval stage. Broodstock were collected in the wild and hormone induced. Spawning yielded eggs that were fertilized and were then incubated until hatching. Larval development was monitored throughout the duration of the trial until all larvae perished. Samples of larval tissue were taken to the lab for lipid analysis and composition was compared at different developmental stages. Larval lipid composition was significantly different across sample groups showing a change in lipid content related to development. After hatching, larvae gradually depleted wax esters‐sterol ester (WE‐SE) reserves over a period of 4 days, while simultaneously increasing hydrocarbon (HC). The role of WE‐SE is seemingly tied to both buoyancy and energy reserves due to its high abundance immediately post‐hatch and selective catabolism. As larvae weaned off of the nutrition provided by the yolk, exogenous feeding began to diversify lipid composition and overall lipid reserves were depleted. Future directions included the development of optimal larval feeds based on this analysis in order to gain more insight into the nutritional needs and requirements during the critical leptocephalus stages.

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Effects of dopamine and melatonin treatment on the expression of the genes associated with artificially induced sexual maturation in Japanese eel, Anguilla japonica

Byun,

Hyeon,

Hettiarachchi

et al. 2024

J Exp Zool Pt A

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Japanese eel (Anguilla japonica) is a commercially important fish species in Asia. Understanding factors like photoperiod, temperature, and lunar cycles is crucial for successful aquaculture and managing its reproduction. Melatonin and dopamine (DA) are essential for regulating reproduction in vertebrates, including fish. This study investigated the effects of melatonin and DA on the reproductive system of mature male Japanese eels to better understand reproductive regulation in fish. To clarify the effects of these hormones on sexual maturation in eels, a critical stage in the reproductive process, sexual maturation was induced by injecting human chorionic gonadotropin, which stimulates the production of sex hormones. To check the effect of melatonin and DA on sexual maturation, DA, melatonin, and DA + domperidone were intraperitoneally injected into fish from each group (six per treatment) at a dose of 1 mg/kg body weight. The fish were then examined using quantitative RT‐PCR by comparing the messenger RNA level of reproduction‐related genes (gonadotropin releasing hormone 1; gnrh1, gonadotropin releasing hormone 2; gnrh2, follicle stimulating hormone; fshβ, luteinizing hormone; lhβ and DA receptor 2b; d2b), involved in the gonadotropic axis in eels, to those that received a control injection. The results indicate significant differences in the expression levels of gnrh1, gnrh2 and d2b in the brain and d2b, fshβ, lhβ in the pituitary at different stages of sexual maturation. Melatonin appears to enhance the production of sex gonadotropins, whereas DA inhibits them. These findings suggest an interaction between melatonin and DA in regulating reproduction in Japanese eels.

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The food source of Sargasso Sea leptocephali

Cited by 16 publications

References 147 publications

18S rRNA gene sequences of leptocephalus gut contents, particulate organic matter, and biological oceanographic conditions in the western North Pacific

18S rRNA gene sequences of leptocephalus gut contents, particulate organic matter, and biological oceanographic conditions in the western North Pacific

Lipid Composition and Utilization in Early Stage Leptocephalus Larvae of Bonefish (Albula vulpes)

Effects of dopamine and melatonin treatment on the expression of the genes associated with artificially induced sexual maturation in Japanese eel, Anguilla japonica

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