Skates are a diverse group within the chondrichthyans and comprise a large component of the bycat... more Skates are a diverse group within the chondrichthyans and comprise a large component of the bycatch in many demersal fisheries. The distribution of the Deepsea Skate, Bathyraja abyssicola, is presently known to be limited to the northern temperate Pacific Ocean. We filmed B. abyssicola from a remote operated vehicle during surveys undertaken on a seamount located north of Darwin Island within the Galapagos Marine Reserve in 2015. This sighting represents the first record of B. abyssicola in the Galapagos Marine Reserve and the first record of the species from anywhere in the tropical eastern Pacific Ocean. The large range extension of this species to tropical low-latitude waters of the Pacific Ocean is a critical contribution to conservation biology of this poorly known species, especially since deepwater skates and rays are generally over-exploited. This new record also highlights our limited knowledge of unique deepwater ecosystems in general and those of the Galapagos Islands in particular.
⎯The blurred smooth lanternshark, Etmopterus bigelowi Shirai and Tachikawa, 1993 was recorded for... more ⎯The blurred smooth lanternshark, Etmopterus bigelowi Shirai and Tachikawa, 1993 was recorded for the first time from Indonesian waters based on two specimens collected from a deepwater shark fishery operated in the Flores Sea, eastern Indonesia. This is also the second confirmed record of Etmopterus species from this country.
The discovery of deep-sea hydrothermal vents in 1977 challenged our views of ecosystem functionin... more The discovery of deep-sea hydrothermal vents in 1977 challenged our views of ecosystem functioning and yet, the research conducted at these extreme and logistically challenging environments still continues to reveal unique biological processes. Here, we report for the first time, a unique behavior where the deep-sea skate, Bathyraja spinosissima, appears to be actively using the elevated temperature of a hydrothermal vent environment to naturally " incubate " developing egg-cases. We hypothesize that this behavior is directly targeted to accelerate embryo development time given that deep-sea skates have some of the longest egg incubation times reported for the animal kingdom. Similar egg incubating behavior, where eggs are incubated in volcanically heated nesting grounds, have been recorded in Cretaceous sauropod dinosaurs and the rare avian megapode. To our knowledge, this is the first time incubating behavior using a volcanic source is recorded for the marine environment. Despite being the largest biome, the deep sea remains the least explored ecosystem on earth 1,2. In 1977, the discovery of the first deep-sea ecosystems supported by hydrothermal vent fluid emissions at the Galapagos Rift, challenged our views of ecosystem functioning and fueled new hypotheses about how life on earth could have originated around these chemically reactive environments 3–5. Forty years later, we now know that hydrothermal vent ecosystems exist in every ocean basin, supporting rich communities and unique biological processes 6–9. Initially considered isolated patches of life within a barren deep-sea floor, we are beginning to appreciate that these ecosystems interact with the surrounding environment and influence global geochemical cycles 7,8. Most hydrothermal vent sites remain unexplored, and our understanding of the ecology of these ecosystems in most parts of the world remains limited. Furthermore, some of these chemosynthesis based ecosystems are now under threat from human activities and are targeted for exploitation of their mineral resources 10,11. Here, we report for the first time a unique behavior where the Pacific white skate Bathyraja spinosissima, one of the deepest living of all known skate species 12 , uses active hydrothermal vent fields as a natural incubator for their external egg-capsules. To the best of our knowledge and understanding, this is the first time this incubating behavior at an active hydrothermal vent field has been recorded for a species within the marine environment. The Galapagos Platform in the eastern tropical Pacific consists of 13 major volcanic islands and numerous seamounts that straddle the equator 13. To the north of the archipelago and parallel to the equator, the Galapagos Spreading Center (GSC) extends for over 1000 km west to east, crossing the Galapagos Marine Reserve north of Darwin Island (Fig. 1). Previous exploration of the area revealed the presence of active hydrothermal vents,
Marine protected areas (MPAs) can potentially alter food web dynamics by increasing the density o... more Marine protected areas (MPAs) can potentially alter food web dynamics by increasing the density of fishes within their borders. Such increases in the density of potential competitors can cause generalist predators to contract the scope of their diets. This study investigated the effects of increased conspecific fish density on the diets of gopher rockfish Sebastes carnatus at a 35 yr old MPA in Point Lobos, California, and at 4 newly established MPAs in Año Nuevo, Point Lobos, Piedras Blancas, and Point Buchon in central California. Analyses were conducted for 707 stomachs collected from 2007 to 2009. Diets did not differ inside versus outside the old Point Lobos MPA in terms of prey richness, evenness, composition, or gopher rockfish trophic level. However, fish outside the MPA had greater levels of individual specialization. No consistent differences in these metrics were observed inside versus outside the 4 new MPAs, although prey composition and evenness did differ significantly among geographic locations. Diets at Año Nuevo, the most northern and shallow location, consisted predominantly of Cancer spp. and porcelain crabs (Porcellanidae), while diets from southern, deeper locations were dominated by brittle stars (Ophiuroidea). The case study of the old Point Lobos MPA indicates that fish feeding ecology may not change in an MPA after several decades. Differences in prey observed among geographic locations suggest variation in the community composition among central California’s new MPAs, which may influence the effect of each MPA on food web dynamics over time.
Hydrolagus africanus (Gilchrist, 1922) is a little-known chimaeroid species, originally described... more Hydrolagus africanus (Gilchrist, 1922) is a little-known chimaeroid species, originally described from the KwaZulu-
Natal coast of South Africa, with a range spanning the western Indian Ocean from Kenya, south to Mozambique and South Africa, and extending into the south-eastern Atlantic to Namibia. This species is characterised by a lateral
patch of denticles on the male prepelvic tenacula, a second dorsal fin slightly indented in the centre, a long, curved
dorsal spine equal to or sometimes exceeding the height of the first dorsal fin, and a uniform light brown body with
no distinctive markings or patterns and slightly darker brown fins. To clarify the taxonomic status of H. africanus,
we examined and compared specimens from throughout its range in southern Africa. Because the syntypes of H. africanus are lost, we designate a neotype and redescribe the species based on the neotype and additional southern African specimens. In addition,
A new arhynchobatid skate, Notoraja martinezi, sp. nov., is described from four specimens collect... more A new arhynchobatid skate, Notoraja martinezi, sp. nov., is described from four specimens collected from the eastern Central Pacific from Costa Rica to Ecuador and between depths of 1256–1472 m. The new species is placed in the genus Notoraja based on the long and flexible rostrum and its proportionally long tail with respect to total length. This species is distinct from its congeners in the Western Pacific by the straight margins of its rostrum, long anterior lobes of pelvic fins, and its abundant and very well developed caudal thorns.
Skates are a diverse group within the chondrichthyans and comprise a large component of the bycat... more Skates are a diverse group within the chondrichthyans and comprise a large component of the bycatch in many demersal fisheries. The distribution of the Deepsea Skate, Bathyraja abyssicola, is presently known to be limited to the northern temperate Pacific Ocean. We filmed B. abyssicola from a remote operated vehicle during surveys undertaken on a seamount located north of Darwin Island within the Galapagos Marine Reserve in 2015. This sighting represents the first record of B. abyssicola in the Galapagos Marine Reserve and the first record of the species from anywhere in the tropical eastern Pacific Ocean. The large range extension of this species to tropical low-latitude waters of the Pacific Ocean is a critical contribution to conservation biology of this poorly known species, especially since deepwater skates and rays are generally over-exploited. This new record also highlights our limited knowledge of unique deepwater ecosystems in general and those of the Galapagos Islands in particular.
⎯The blurred smooth lanternshark, Etmopterus bigelowi Shirai and Tachikawa, 1993 was recorded for... more ⎯The blurred smooth lanternshark, Etmopterus bigelowi Shirai and Tachikawa, 1993 was recorded for the first time from Indonesian waters based on two specimens collected from a deepwater shark fishery operated in the Flores Sea, eastern Indonesia. This is also the second confirmed record of Etmopterus species from this country.
The discovery of deep-sea hydrothermal vents in 1977 challenged our views of ecosystem functionin... more The discovery of deep-sea hydrothermal vents in 1977 challenged our views of ecosystem functioning and yet, the research conducted at these extreme and logistically challenging environments still continues to reveal unique biological processes. Here, we report for the first time, a unique behavior where the deep-sea skate, Bathyraja spinosissima, appears to be actively using the elevated temperature of a hydrothermal vent environment to naturally " incubate " developing egg-cases. We hypothesize that this behavior is directly targeted to accelerate embryo development time given that deep-sea skates have some of the longest egg incubation times reported for the animal kingdom. Similar egg incubating behavior, where eggs are incubated in volcanically heated nesting grounds, have been recorded in Cretaceous sauropod dinosaurs and the rare avian megapode. To our knowledge, this is the first time incubating behavior using a volcanic source is recorded for the marine environment. Despite being the largest biome, the deep sea remains the least explored ecosystem on earth 1,2. In 1977, the discovery of the first deep-sea ecosystems supported by hydrothermal vent fluid emissions at the Galapagos Rift, challenged our views of ecosystem functioning and fueled new hypotheses about how life on earth could have originated around these chemically reactive environments 3–5. Forty years later, we now know that hydrothermal vent ecosystems exist in every ocean basin, supporting rich communities and unique biological processes 6–9. Initially considered isolated patches of life within a barren deep-sea floor, we are beginning to appreciate that these ecosystems interact with the surrounding environment and influence global geochemical cycles 7,8. Most hydrothermal vent sites remain unexplored, and our understanding of the ecology of these ecosystems in most parts of the world remains limited. Furthermore, some of these chemosynthesis based ecosystems are now under threat from human activities and are targeted for exploitation of their mineral resources 10,11. Here, we report for the first time a unique behavior where the Pacific white skate Bathyraja spinosissima, one of the deepest living of all known skate species 12 , uses active hydrothermal vent fields as a natural incubator for their external egg-capsules. To the best of our knowledge and understanding, this is the first time this incubating behavior at an active hydrothermal vent field has been recorded for a species within the marine environment. The Galapagos Platform in the eastern tropical Pacific consists of 13 major volcanic islands and numerous seamounts that straddle the equator 13. To the north of the archipelago and parallel to the equator, the Galapagos Spreading Center (GSC) extends for over 1000 km west to east, crossing the Galapagos Marine Reserve north of Darwin Island (Fig. 1). Previous exploration of the area revealed the presence of active hydrothermal vents,
Marine protected areas (MPAs) can potentially alter food web dynamics by increasing the density o... more Marine protected areas (MPAs) can potentially alter food web dynamics by increasing the density of fishes within their borders. Such increases in the density of potential competitors can cause generalist predators to contract the scope of their diets. This study investigated the effects of increased conspecific fish density on the diets of gopher rockfish Sebastes carnatus at a 35 yr old MPA in Point Lobos, California, and at 4 newly established MPAs in Año Nuevo, Point Lobos, Piedras Blancas, and Point Buchon in central California. Analyses were conducted for 707 stomachs collected from 2007 to 2009. Diets did not differ inside versus outside the old Point Lobos MPA in terms of prey richness, evenness, composition, or gopher rockfish trophic level. However, fish outside the MPA had greater levels of individual specialization. No consistent differences in these metrics were observed inside versus outside the 4 new MPAs, although prey composition and evenness did differ significantly among geographic locations. Diets at Año Nuevo, the most northern and shallow location, consisted predominantly of Cancer spp. and porcelain crabs (Porcellanidae), while diets from southern, deeper locations were dominated by brittle stars (Ophiuroidea). The case study of the old Point Lobos MPA indicates that fish feeding ecology may not change in an MPA after several decades. Differences in prey observed among geographic locations suggest variation in the community composition among central California’s new MPAs, which may influence the effect of each MPA on food web dynamics over time.
Hydrolagus africanus (Gilchrist, 1922) is a little-known chimaeroid species, originally described... more Hydrolagus africanus (Gilchrist, 1922) is a little-known chimaeroid species, originally described from the KwaZulu-
Natal coast of South Africa, with a range spanning the western Indian Ocean from Kenya, south to Mozambique and South Africa, and extending into the south-eastern Atlantic to Namibia. This species is characterised by a lateral
patch of denticles on the male prepelvic tenacula, a second dorsal fin slightly indented in the centre, a long, curved
dorsal spine equal to or sometimes exceeding the height of the first dorsal fin, and a uniform light brown body with
no distinctive markings or patterns and slightly darker brown fins. To clarify the taxonomic status of H. africanus,
we examined and compared specimens from throughout its range in southern Africa. Because the syntypes of H. africanus are lost, we designate a neotype and redescribe the species based on the neotype and additional southern African specimens. In addition,
A new arhynchobatid skate, Notoraja martinezi, sp. nov., is described from four specimens collect... more A new arhynchobatid skate, Notoraja martinezi, sp. nov., is described from four specimens collected from the eastern Central Pacific from Costa Rica to Ecuador and between depths of 1256–1472 m. The new species is placed in the genus Notoraja based on the long and flexible rostrum and its proportionally long tail with respect to total length. This species is distinct from its congeners in the Western Pacific by the straight margins of its rostrum, long anterior lobes of pelvic fins, and its abundant and very well developed caudal thorns.
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can cause generalist predators to contract the scope of their diets. This study investigated the effects of increased conspecific fish density on the diets of gopher rockfish Sebastes carnatus at a 35 yr old MPA in Point Lobos, California, and at 4 newly established MPAs in Año Nuevo, Point
Lobos, Piedras Blancas, and Point Buchon in central California. Analyses were conducted for 707 stomachs collected from 2007 to 2009. Diets did not differ inside versus outside the old Point Lobos MPA in terms of prey richness, evenness, composition, or gopher rockfish trophic level. However, fish outside the MPA had greater levels of individual specialization. No consistent differences in these metrics were observed inside versus outside the 4 new MPAs, although prey composition
and evenness did differ significantly among geographic locations. Diets at Año Nuevo, the most northern and shallow location, consisted predominantly of Cancer spp. and porcelain crabs (Porcellanidae), while diets from southern, deeper locations were dominated by brittle stars (Ophiuroidea).
The case study of the old Point Lobos MPA indicates that fish feeding ecology may not change in an MPA after several decades. Differences in prey observed among geographic locations suggest variation in the community composition among central California’s new MPAs, which may influence the effect of each MPA on food web dynamics over time.
Natal coast of South Africa, with a range spanning the western Indian Ocean from Kenya, south to Mozambique and South Africa, and extending into the south-eastern Atlantic to Namibia. This species is characterised by a lateral
patch of denticles on the male prepelvic tenacula, a second dorsal fin slightly indented in the centre, a long, curved
dorsal spine equal to or sometimes exceeding the height of the first dorsal fin, and a uniform light brown body with
no distinctive markings or patterns and slightly darker brown fins. To clarify the taxonomic status of H. africanus,
we examined and compared specimens from throughout its range in southern Africa. Because the syntypes of H. africanus are lost, we designate a neotype and redescribe the species based on the neotype and additional southern African specimens. In addition,
Central Pacific from Costa Rica to Ecuador and between depths of 1256–1472 m. The new species is placed in the genus
Notoraja based on the long and flexible rostrum and its proportionally long tail with respect to total length. This species
is distinct from its congeners in the Western Pacific by the straight margins of its rostrum, long anterior lobes of pelvic
fins, and its abundant and very well developed caudal thorns.
can cause generalist predators to contract the scope of their diets. This study investigated the effects of increased conspecific fish density on the diets of gopher rockfish Sebastes carnatus at a 35 yr old MPA in Point Lobos, California, and at 4 newly established MPAs in Año Nuevo, Point
Lobos, Piedras Blancas, and Point Buchon in central California. Analyses were conducted for 707 stomachs collected from 2007 to 2009. Diets did not differ inside versus outside the old Point Lobos MPA in terms of prey richness, evenness, composition, or gopher rockfish trophic level. However, fish outside the MPA had greater levels of individual specialization. No consistent differences in these metrics were observed inside versus outside the 4 new MPAs, although prey composition
and evenness did differ significantly among geographic locations. Diets at Año Nuevo, the most northern and shallow location, consisted predominantly of Cancer spp. and porcelain crabs (Porcellanidae), while diets from southern, deeper locations were dominated by brittle stars (Ophiuroidea).
The case study of the old Point Lobos MPA indicates that fish feeding ecology may not change in an MPA after several decades. Differences in prey observed among geographic locations suggest variation in the community composition among central California’s new MPAs, which may influence the effect of each MPA on food web dynamics over time.
Natal coast of South Africa, with a range spanning the western Indian Ocean from Kenya, south to Mozambique and South Africa, and extending into the south-eastern Atlantic to Namibia. This species is characterised by a lateral
patch of denticles on the male prepelvic tenacula, a second dorsal fin slightly indented in the centre, a long, curved
dorsal spine equal to or sometimes exceeding the height of the first dorsal fin, and a uniform light brown body with
no distinctive markings or patterns and slightly darker brown fins. To clarify the taxonomic status of H. africanus,
we examined and compared specimens from throughout its range in southern Africa. Because the syntypes of H. africanus are lost, we designate a neotype and redescribe the species based on the neotype and additional southern African specimens. In addition,
Central Pacific from Costa Rica to Ecuador and between depths of 1256–1472 m. The new species is placed in the genus
Notoraja based on the long and flexible rostrum and its proportionally long tail with respect to total length. This species
is distinct from its congeners in the Western Pacific by the straight margins of its rostrum, long anterior lobes of pelvic
fins, and its abundant and very well developed caudal thorns.