Table_1_Transcriptional changes in the gilthead seabream (Sparus aurata) skin in response to ultraviolet B radiation exposure.xlsx

Solar ultraviolet B radiation (UVB) has recently been described as a relevant stressor in fish confined to aquaculture cages. In gilthead seabream (Sparus aurata), UVB exposure resulted in decreased growth, epidermal sloughing, increased oxidative stress in the skin, and induced changes in behavior, physiology, and immune system. Several molecular responses should accompany such detrimental effects; however, little is known in fish about the overall UVB-mediated changes at the transcriptional level. Thus, this study aimed to investigate the effects of UVB exposure on the global gene expression profiles of S. aurata skin through transcriptome analysis. S. aurata juveniles were exposed for 43 days to two experimental groups: 1) UVB (daily dose, 6 kJ m-2; representing levels between 5 and 7 m depth); 2) Unirradiated treatment, used as a control. The comparison of skin transcriptomes between the control and UVB treatments revealed 845 differentially expressed genes (580 up-regulated and 265 down-regulated). The reliability of the transcriptome analysis was confirmed by qRT-PCR for selected genes. Functional annotation and PPI analyses revealed that genes related to the immune system and inflammatory response, cell cycle regulation, proteasome, proteolysis, and oxidative stress might be involved in the response to UVB exposure. In contrast, UVB exposure inhibited the expression of several genes related to growth factor activity, cell growth and differentiation, and pigmentation. p53 signaling pathway was enriched in fish exposed to UVB. Moreover, pathways involved in the immune system and inflammatory response (cytokine-cytokine receptor interaction, RIG-I-like receptor signaling pathway, and Toll-like receptor signaling pathway) were also enriched in the skin of UVB-exposed fish. UVB-induced skin damage and a high level of infiltration of immune-related cells were confirmed through histopathological examination. Together, our results provide noteworthy insights into the molecular changes in fish after long-term exposure to UVB. These findings will help in the future to identify biomarkers of fish reared in offshore aquaculture systems in oligotrophic and highly transparent waters.</p

Table_3_Transcriptional changes in the gilthead seabream (Sparus aurata) skin in response to ultraviolet B radiation exposure.xlsx

Solar ultraviolet B radiation (UVB) has recently been described as a relevant stressor in fish confined to aquaculture cages. In gilthead seabream (Sparus aurata), UVB exposure resulted in decreased growth, epidermal sloughing, increased oxidative stress in the skin, and induced changes in behavior, physiology, and immune system. Several molecular responses should accompany such detrimental effects; however, little is known in fish about the overall UVB-mediated changes at the transcriptional level. Thus, this study aimed to investigate the effects of UVB exposure on the global gene expression profiles of S. aurata skin through transcriptome analysis. S. aurata juveniles were exposed for 43 days to two experimental groups: 1) UVB (daily dose, 6 kJ m-2; representing levels between 5 and 7 m depth); 2) Unirradiated treatment, used as a control. The comparison of skin transcriptomes between the control and UVB treatments revealed 845 differentially expressed genes (580 up-regulated and 265 down-regulated). The reliability of the transcriptome analysis was confirmed by qRT-PCR for selected genes. Functional annotation and PPI analyses revealed that genes related to the immune system and inflammatory response, cell cycle regulation, proteasome, proteolysis, and oxidative stress might be involved in the response to UVB exposure. In contrast, UVB exposure inhibited the expression of several genes related to growth factor activity, cell growth and differentiation, and pigmentation. p53 signaling pathway was enriched in fish exposed to UVB. Moreover, pathways involved in the immune system and inflammatory response (cytokine-cytokine receptor interaction, RIG-I-like receptor signaling pathway, and Toll-like receptor signaling pathway) were also enriched in the skin of UVB-exposed fish. UVB-induced skin damage and a high level of infiltration of immune-related cells were confirmed through histopathological examination. Together, our results provide noteworthy insights into the molecular changes in fish after long-term exposure to UVB. These findings will help in the future to identify biomarkers of fish reared in offshore aquaculture systems in oligotrophic and highly transparent waters.</p

Table_2_Transcriptional changes in the gilthead seabream (Sparus aurata) skin in response to ultraviolet B radiation exposure.xlsx

Solar ultraviolet B radiation (UVB) has recently been described as a relevant stressor in fish confined to aquaculture cages. In gilthead seabream (Sparus aurata), UVB exposure resulted in decreased growth, epidermal sloughing, increased oxidative stress in the skin, and induced changes in behavior, physiology, and immune system. Several molecular responses should accompany such detrimental effects; however, little is known in fish about the overall UVB-mediated changes at the transcriptional level. Thus, this study aimed to investigate the effects of UVB exposure on the global gene expression profiles of S. aurata skin through transcriptome analysis. S. aurata juveniles were exposed for 43 days to two experimental groups: 1) UVB (daily dose, 6 kJ m-2; representing levels between 5 and 7 m depth); 2) Unirradiated treatment, used as a control. The comparison of skin transcriptomes between the control and UVB treatments revealed 845 differentially expressed genes (580 up-regulated and 265 down-regulated). The reliability of the transcriptome analysis was confirmed by qRT-PCR for selected genes. Functional annotation and PPI analyses revealed that genes related to the immune system and inflammatory response, cell cycle regulation, proteasome, proteolysis, and oxidative stress might be involved in the response to UVB exposure. In contrast, UVB exposure inhibited the expression of several genes related to growth factor activity, cell growth and differentiation, and pigmentation. p53 signaling pathway was enriched in fish exposed to UVB. Moreover, pathways involved in the immune system and inflammatory response (cytokine-cytokine receptor interaction, RIG-I-like receptor signaling pathway, and Toll-like receptor signaling pathway) were also enriched in the skin of UVB-exposed fish. UVB-induced skin damage and a high level of infiltration of immune-related cells were confirmed through histopathological examination. Together, our results provide noteworthy insights into the molecular changes in fish after long-term exposure to UVB. These findings will help in the future to identify biomarkers of fish reared in offshore aquaculture systems in oligotrophic and highly transparent waters.</p

DataSheet_1_Transcriptional changes in the gilthead seabream (Sparus aurata) skin in response to ultraviolet B radiation exposure.docx

Solar ultraviolet B radiation (UVB) has recently been described as a relevant stressor in fish confined to aquaculture cages. In gilthead seabream (Sparus aurata), UVB exposure resulted in decreased growth, epidermal sloughing, increased oxidative stress in the skin, and induced changes in behavior, physiology, and immune system. Several molecular responses should accompany such detrimental effects; however, little is known in fish about the overall UVB-mediated changes at the transcriptional level. Thus, this study aimed to investigate the effects of UVB exposure on the global gene expression profiles of S. aurata skin through transcriptome analysis. S. aurata juveniles were exposed for 43 days to two experimental groups: 1) UVB (daily dose, 6 kJ m-2; representing levels between 5 and 7 m depth); 2) Unirradiated treatment, used as a control. The comparison of skin transcriptomes between the control and UVB treatments revealed 845 differentially expressed genes (580 up-regulated and 265 down-regulated). The reliability of the transcriptome analysis was confirmed by qRT-PCR for selected genes. Functional annotation and PPI analyses revealed that genes related to the immune system and inflammatory response, cell cycle regulation, proteasome, proteolysis, and oxidative stress might be involved in the response to UVB exposure. In contrast, UVB exposure inhibited the expression of several genes related to growth factor activity, cell growth and differentiation, and pigmentation. p53 signaling pathway was enriched in fish exposed to UVB. Moreover, pathways involved in the immune system and inflammatory response (cytokine-cytokine receptor interaction, RIG-I-like receptor signaling pathway, and Toll-like receptor signaling pathway) were also enriched in the skin of UVB-exposed fish. UVB-induced skin damage and a high level of infiltration of immune-related cells were confirmed through histopathological examination. Together, our results provide noteworthy insights into the molecular changes in fish after long-term exposure to UVB. These findings will help in the future to identify biomarkers of fish reared in offshore aquaculture systems in oligotrophic and highly transparent waters.</p

Table_1_First record of a live adult heteropod Firoloida desmarestia in the Red Sea.pdf

Observations are essential to explore and discover the ocean. The rapid advancements in technology have revolutionized our capacity to document the ocean and its diverse array of species, pushing the boundaries of our understanding further than ever before. The central Red Sea was exposed as part of the Red Sea Decade Expedition, which took place from 04 February to 18 June 2022 aboard the R/V OceanXplorer, using underwater submersibles. Here, for the first time in the Red Sea, we reported three observations of living Firoloida desmarestia specimens, one female and two male specimens, a heteropod from the Pterotracheidae family. This shell-less mollusk has been observed in the epipelagic zone of the world’s oceans, with the exception of polar regions, suggesting a global distribution for these observations. The two males were observed swimming in the water column, while the female was close to the seabed. All three observations were detected during the morning, raising the question if these organisms use vertical migrations to reach deep-sea waters during the daytime. However, no ROV or submersible dives were conducted at night. Our results show a depth range expansion for observations of this species in the Red Sea. Furthermore, as far as we know, no adults of F. desmarestia have been reported until now in the Red Sea. During the expedition, all three specimens were found at similar depths (350, 400, and 464.5 m depth), with the female being the deepest, thus confirming the eurybathic distribution of this species. The emerging technology is progressively enhancing our understanding of these enigmatic creatures and expanding our knowledge of their fascinating adaptations and ecological roles. In addition to our fieldwork, a literature search was performed to uncover any pre-existing observational records of this species to understand its global distribution and ecological significance.</p

Video_6_First record of a live adult heteropod Firoloida desmarestia in the Red Sea.mp4

Observations are essential to explore and discover the ocean. The rapid advancements in technology have revolutionized our capacity to document the ocean and its diverse array of species, pushing the boundaries of our understanding further than ever before. The central Red Sea was exposed as part of the Red Sea Decade Expedition, which took place from 04 February to 18 June 2022 aboard the R/V OceanXplorer, using underwater submersibles. Here, for the first time in the Red Sea, we reported three observations of living Firoloida desmarestia specimens, one female and two male specimens, a heteropod from the Pterotracheidae family. This shell-less mollusk has been observed in the epipelagic zone of the world’s oceans, with the exception of polar regions, suggesting a global distribution for these observations. The two males were observed swimming in the water column, while the female was close to the seabed. All three observations were detected during the morning, raising the question if these organisms use vertical migrations to reach deep-sea waters during the daytime. However, no ROV or submersible dives were conducted at night. Our results show a depth range expansion for observations of this species in the Red Sea. Furthermore, as far as we know, no adults of F. desmarestia have been reported until now in the Red Sea. During the expedition, all three specimens were found at similar depths (350, 400, and 464.5 m depth), with the female being the deepest, thus confirming the eurybathic distribution of this species. The emerging technology is progressively enhancing our understanding of these enigmatic creatures and expanding our knowledge of their fascinating adaptations and ecological roles. In addition to our fieldwork, a literature search was performed to uncover any pre-existing observational records of this species to understand its global distribution and ecological significance.</p

Video_3_First record of a live adult heteropod Firoloida desmarestia in the Red Sea.mp4

Observations are essential to explore and discover the ocean. The rapid advancements in technology have revolutionized our capacity to document the ocean and its diverse array of species, pushing the boundaries of our understanding further than ever before. The central Red Sea was exposed as part of the Red Sea Decade Expedition, which took place from 04 February to 18 June 2022 aboard the R/V OceanXplorer, using underwater submersibles. Here, for the first time in the Red Sea, we reported three observations of living Firoloida desmarestia specimens, one female and two male specimens, a heteropod from the Pterotracheidae family. This shell-less mollusk has been observed in the epipelagic zone of the world’s oceans, with the exception of polar regions, suggesting a global distribution for these observations. The two males were observed swimming in the water column, while the female was close to the seabed. All three observations were detected during the morning, raising the question if these organisms use vertical migrations to reach deep-sea waters during the daytime. However, no ROV or submersible dives were conducted at night. Our results show a depth range expansion for observations of this species in the Red Sea. Furthermore, as far as we know, no adults of F. desmarestia have been reported until now in the Red Sea. During the expedition, all three specimens were found at similar depths (350, 400, and 464.5 m depth), with the female being the deepest, thus confirming the eurybathic distribution of this species. The emerging technology is progressively enhancing our understanding of these enigmatic creatures and expanding our knowledge of their fascinating adaptations and ecological roles. In addition to our fieldwork, a literature search was performed to uncover any pre-existing observational records of this species to understand its global distribution and ecological significance.</p

Video_4_First record of a live adult heteropod Firoloida desmarestia in the Red Sea.mp4

Observations are essential to explore and discover the ocean. The rapid advancements in technology have revolutionized our capacity to document the ocean and its diverse array of species, pushing the boundaries of our understanding further than ever before. The central Red Sea was exposed as part of the Red Sea Decade Expedition, which took place from 04 February to 18 June 2022 aboard the R/V OceanXplorer, using underwater submersibles. Here, for the first time in the Red Sea, we reported three observations of living Firoloida desmarestia specimens, one female and two male specimens, a heteropod from the Pterotracheidae family. This shell-less mollusk has been observed in the epipelagic zone of the world’s oceans, with the exception of polar regions, suggesting a global distribution for these observations. The two males were observed swimming in the water column, while the female was close to the seabed. All three observations were detected during the morning, raising the question if these organisms use vertical migrations to reach deep-sea waters during the daytime. However, no ROV or submersible dives were conducted at night. Our results show a depth range expansion for observations of this species in the Red Sea. Furthermore, as far as we know, no adults of F. desmarestia have been reported until now in the Red Sea. During the expedition, all three specimens were found at similar depths (350, 400, and 464.5 m depth), with the female being the deepest, thus confirming the eurybathic distribution of this species. The emerging technology is progressively enhancing our understanding of these enigmatic creatures and expanding our knowledge of their fascinating adaptations and ecological roles. In addition to our fieldwork, a literature search was performed to uncover any pre-existing observational records of this species to understand its global distribution and ecological significance.</p

Video_1_First record of a live adult heteropod Firoloida desmarestia in the Red Sea.mp4

Observations are essential to explore and discover the ocean. The rapid advancements in technology have revolutionized our capacity to document the ocean and its diverse array of species, pushing the boundaries of our understanding further than ever before. The central Red Sea was exposed as part of the Red Sea Decade Expedition, which took place from 04 February to 18 June 2022 aboard the R/V OceanXplorer, using underwater submersibles. Here, for the first time in the Red Sea, we reported three observations of living Firoloida desmarestia specimens, one female and two male specimens, a heteropod from the Pterotracheidae family. This shell-less mollusk has been observed in the epipelagic zone of the world’s oceans, with the exception of polar regions, suggesting a global distribution for these observations. The two males were observed swimming in the water column, while the female was close to the seabed. All three observations were detected during the morning, raising the question if these organisms use vertical migrations to reach deep-sea waters during the daytime. However, no ROV or submersible dives were conducted at night. Our results show a depth range expansion for observations of this species in the Red Sea. Furthermore, as far as we know, no adults of F. desmarestia have been reported until now in the Red Sea. During the expedition, all three specimens were found at similar depths (350, 400, and 464.5 m depth), with the female being the deepest, thus confirming the eurybathic distribution of this species. The emerging technology is progressively enhancing our understanding of these enigmatic creatures and expanding our knowledge of their fascinating adaptations and ecological roles. In addition to our fieldwork, a literature search was performed to uncover any pre-existing observational records of this species to understand its global distribution and ecological significance.</p

Video_2_First record of a live adult heteropod Firoloida desmarestia in the Red Sea.mp4

Observations are essential to explore and discover the ocean. The rapid advancements in technology have revolutionized our capacity to document the ocean and its diverse array of species, pushing the boundaries of our understanding further than ever before. The central Red Sea was exposed as part of the Red Sea Decade Expedition, which took place from 04 February to 18 June 2022 aboard the R/V OceanXplorer, using underwater submersibles. Here, for the first time in the Red Sea, we reported three observations of living Firoloida desmarestia specimens, one female and two male specimens, a heteropod from the Pterotracheidae family. This shell-less mollusk has been observed in the epipelagic zone of the world’s oceans, with the exception of polar regions, suggesting a global distribution for these observations. The two males were observed swimming in the water column, while the female was close to the seabed. All three observations were detected during the morning, raising the question if these organisms use vertical migrations to reach deep-sea waters during the daytime. However, no ROV or submersible dives were conducted at night. Our results show a depth range expansion for observations of this species in the Red Sea. Furthermore, as far as we know, no adults of F. desmarestia have been reported until now in the Red Sea. During the expedition, all three specimens were found at similar depths (350, 400, and 464.5 m depth), with the female being the deepest, thus confirming the eurybathic distribution of this species. The emerging technology is progressively enhancing our understanding of these enigmatic creatures and expanding our knowledge of their fascinating adaptations and ecological roles. In addition to our fieldwork, a literature search was performed to uncover any pre-existing observational records of this species to understand its global distribution and ecological significance.</p