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Oceanic fauna of the Atlantic
JOrnitho: I'm opening this new topic because I finished the description of fish. However, I don't know which scientific name it could have. Any suggestions? Blue porpoise fish A member of the Mugilidae family, the blue porpoise fish is the type species of the genus. An inhabitant of the Atlantic Ocean, this species evolved to fill the niche left behind by dolphins, porpoises and tunas when they went extinct during the transition between the Holocene and the Neocene. All the members of this genus have the habit of constantly jumping from the water. The blue porpoise fish have 120 cm of length. They have an elongate, fusiform body with a long, pointed snout. The eyes are large and covered by an adipose eyelid, while the teeth are small, sharp, and conical. Scales are also small, with the exceptions of those immediately posterior to the head and around the pectoral fins. These small scales give the fish a velvet-like feel. The two dorsal fins are large and bright yellow, being spaced far apart. The second dorsal fin is typically followed by 4 dorsal finlets. Its body is blue dorsally, while the rest is silvery-white and has darker splotches. When feeding on larger prey, schools tend to break down into shoals and individuals find food on their own. When consuming plankton, however, blue porpoise fish form tight aggregations, open their mouths as wide as possible, and extend their operculums, swimming in a tightly-packed school that acts like a series of miniature tow nets. Spaced only about the diameter of a single fish's mouth apart, this formation greatly reduces the ability of plankton to evade capture, as a plankton darting out of the way of one fish is likely to end up in the jaws of another. These fishes are followed by seabirds, which will use them to locate prey in similar way to how it happened with cetaceans in the Holocene. Reproduction in the blue porpoise fish is oviparous. Spawning occurs day or night in the spring and summer months, primarily within 52 km of shore, though it can occur as far out as 130 km. A single female can spawn as many as 420,000 eggs in a spawning season. Eggs mature in batches over the course of a week and are pelagic once released, remaining within 15–25 of the surface. Time to hatching is dependent on the water temperature, and ranges from 2 days at 21 °C to 8 days at 10 °C. Most eggs are spawned in waters 12 °C in temperature, and as such the majority of eggs hatch in about a week. Eggs are anywhere from 1.0–1.3 mm in size, trending towards smaller as the spawning season goes on. Larvae undergo three developmental stages: the yolk sac stage, the larval stage, and the post-larval stage. Larvae are 3 mm when they hatch and feed on the yolk sac for about 5 days. During the larval stage, which lasts about a month, larvae grow to 10 mm in length. They are largely incapable of swimming, instead floating with the current. During the post-larval stage, which occurs over the next 40 days and during which the fish reaches 50 mm in length, it swims to the surface at night and down to deeper waters during the day. At the end of the post-larval stage, juveniles resemble an adult mackerel in all but size. Schooling behavior occurs around this time. Sexual maturity is reached at around 2 years of age, though some fish may reproduce a season earlier or a season later. Though some fish are sexually mature at 39 cm in length, even by 45 cm only about half of females will be ready to reproduce. At 53 cm, most fishes are capable of reproduction. A blue porpoise fish can live for up to 21 years.
Îòâåòîâ - 4
JOrnitho: Sometime ago, I and ëÿãóøêà talked about these two species of fish. I started working on the description, but forgot about them. I found them today and decided to finish. Colossal goby (Megalogobius vexilliopinna) Order: Gobiiformes Family: Gobiidae Habitat: Across the Atlantic Ocean, with populations inhabiting the Northern and Southern parts of this ocean. The planktonic collapse during the boundary between the Holocene and Neocene had caused the extinction of the baleen whales. With time, new species evolved to fill their niches. The fishes that survived this catastrophe at the sea soon found themselves with the chance of becoming the new marine megafauna. Among them is the colossal goby, a large descendant of the true gobbies (Gobiinae). An inhabitant of the Atlantic Ocean, with populations inhabiting its Northern and Southern parts, this species is one of the largest fishes in this ocean. As their name says, the colossal gobies are large fishes. A full grown male has a length of 10 m, while the females reach 9 m. The head is depressed with a protruding lower jaw while the body takes on a compressed appearance towards the caudal fin. Normally blue or silver-blue with various black stripes along the sides. These stripes vary between individuals. The fins are rounded and brownish-yellow. Males have a dorsal fin that can reach 2 m when extended. It’s bright yellowish-red with a large black circle with white at the center, similar to an eye. The females have a brown colored 1 m dorsal fin. Colossal goby’s diet is composed of smaller fishes and squids. When hunting, these fishes will open their mouth, which can extend up to nearly 3 m in large individuals, and use their strong tails to have a brief burst of speed. Then, they’ll cross a shoal while swallowing any prey that ends inside their mouth. When there is an abundance of food, they form hunting groups. Colossal gobies can also be seen hunting with other predators, which sometimes can be eaten by accident. This species is migratory, individuals living in the temperate areas of both hemispheres will move to tropical areas during the winter. Their reproduction happens during these periods, with mating grounds being in warm places such as the Gulf of Mexico, the tropical coasts of South America and Africa. During mating, the males will show their colorful dorsal fins to the females while the two swim side by side. Until the eggs are laid, the males will fiercely protect the female, hitting each other with their strong tails. The females have preference for large males since they’ll be the ones to carry the eggs inside their mouths, protecting them. During five weeks, the male is incapable of eating and uses the movement of gills to flow fresh water to the eggs. They use their fat reservoirs to survive without food. The female abandons him shortly after the eggs are fertilized. She can lay as much as one hundred. When the young hatch, the male opens his mouth to make them leave. The fry will not stay too long around the male, gathering in shoals with other young. They’ll remain this way until reaching 4 m. Due to the adults’ size, they don’t have any predators. Only large sharks and the orca squid are capable of killing smaller individuals. During migration, it’s common for sick and weak individuals to end beached along the coast. They have a lifespan of 80 years. The Pacific colossal goby (Megalogobius pacificus) is a closely related species that inhabit the Pacific Ocean in both hemispheres. It’s very similar in size and color, with the only exception being that males have bright orange dorsal fins and thin stripes. The striped colossal goby (Megalogobius striatus) is close related to the pacific species. They are similar to the Pacific one, but have longer and thick stripes at the side of their bodies. Fanged drum (Pogonivorax dentata) Order: Acanthuriformes Family: Sciaenidae Habitat: Across the Atlantic Ocean, in tropical and temperate waters. The planktonic collapse during the boundary between the Holocene and Neocene had caused the extinction of many sea predators. In the Neocene, the niches left by them were soon filled by other species. Among them is the fanged drum, a large predatory and pelagic descendant of the drum (Pogonias). This species inhabits the Atlantic Ocean, living in tropical and temperate waters. The fanged drum is very different from its ancestors. With a torpedo-like body and blade shaped fins, it became an analogue to predatory fishes such as the tarpon and the prehistoric Xiphactinus. They have modified fang-like teeth that are used to cut through their prey. They are silvery grey with black circles at the side and white underparts. The fins are yellow colored. Their body length ranges from 3 to 4 m. Their body is very flexible, allowing them to even jump out of the water. This species is a predator, hunting other fishes, squids and sea birds. They use their teeth to tear through the prey’s body. Fast, they can pursue prey for long distances. Cannibalism is common among fanged drums, with large individuals killing smaller ones during feeding frenzies. The fanged drum is a solitary species, only gathering during reproduction or when large shoals of prey attract many individuals. They patrol the ocean in search of food, visiting the waters near seabird’s nesting colonies with the purpose of snatching young birds learning to fly. They breed during the entire year, with the fishes gathering in large congregations. The males will vibrate their strong muscles against its swim blade to make a loud sound. The loudests will gather more females around themselves, which will liberate their eggs in the water for the male to fecund. A healthy male fanged drum can liberate more gametes than other species of fish. It takes four years for a young to reach the minimum size of an adult and start breeding. They have a lifespan of 50 years. The yellow fanged drum (Pogonivorax flaviventer) is close related species that inhabit the tropical and temperate waters of East Pacific Ocean. Their lenght range from 3 to 4 m, similar to that of the Atlantic species. They are characterized by a pale yellow belly and orange fins.
Àâòîð: JOrnitho ïèøåò: A member of the Scombridae family Scombridae - mackerels and tunas - are extinct in Neocene due to "plankton catastrophe" (the drastic decline of diversity and number of plankton invertebrates on the border of Holocene and Neocene). Pelagic fishes of the open ocean are representatives of the fishes of nearshore areas and sea shallows. Many fish families, which representatives spend a lot of time in plankton or depend on plankton, are extinct.
ìåäâåäü: Interesting fish! But why do Atlantic and Indian ocean share the same species? As far as I know it it more common for the Indian Ocean to have species in common with the western Pacific Ocean.
JOrnitho: Àâòîð ïèøåò: Scombridae - mackerels and tunas - are extinct in Neocene due to "plankton catastrophe" (the drastic decline of diversity and number of plankton invertebrates on the border of Holocene and Neocene). Pelagic fishes of the open ocean are representatives of the fishes of nearshore areas and sea shallows. Many fish families, which representatives spend a lot of time in plankton or depend on plankton, are extinct. This one was made years ago, when I didn’t knew that Scombridae were extinct. I'll edit for a descendant of the Mugilidae family. ìåäâåäü ïèøåò: Interesting fish! But why do Atlantic and Indian ocean share the same species? As far as I know it it more common for the Indian Ocean to have species in common with the western Pacific Ocean. I'll edit to suit it and make some species for the Indian and Pacific.
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