Yathrib was a dusty frontier world when it was discovered the Pan Arabian Mercantile Alliance in the years before the Prophet saw the Holy Flame, and so it had few enough native species - and much of what was native were killed by share colonists in the early years of colonization or just displaced by their imported animals, some of which escaped to the wild and adapted. Yet another source of exotic animals were the menageries in Iskandretta and other places; the city by the White Oasis was famed for its exotic zoos, and after the Fall animal-rights activists released many of the inmates of those zoos into the wild, where they have subsequently bred.
Yathrib's native creatures are not terribly different than many of Holy Terra's local species. In the Second Republic, some theorized that this - like similar creatures on other worlds - is the product of tinkering by the promethean Ur. Still, they have their own distinctive characteristics. Many of Yathrib's species have exaggerated life cycles, with even higher-order animals undergoing meaningful changes in physiology and behavior during different parts of their life. Many of Yathrib's natives - even its mammals - are egg-layers, often laying their young in flexible cases like the mermaid's purses of Old Urth. Terrestrial mammals tend to store these cases in marsupial-like pouches, providing the egg cases external nutrition until their young have finished developing.
Perhaps the most iconic of Yathrib's native species, the Yathrib lion is a septadactyl predator feared by the herdsmen of the Shining Gulf and elsewhere. It has a powerful, strongly muscled body and long canine teeth that grow throughout the first stage of its life. This first stage - the hunter stage - leaves the lion a solitary predator, but several years after sexual maturity the lions' teeth stop growing and they join a pride, instead exhibiting group behavior almost like Old Urth wolves. Prior to the pride stage, Yathrib lions never display manes, but once they join a pride manes sometimes develop.
Some few lions' teeth never stop growing; they take on the appearance of a saber-toothed cat, never joining a pride. Such 'eternal nomads' are considered truly deadly. The 'pious lion' that famously knelt to the Prophet at Leon is by tradition said to be one of these eternal nomads, and legend has it that he still roams the Shining Gulf.
The Johbock is a sort of marsupial deer. When young, the johbock is sometimes called the johspringer, and is renowned for its leaping ability. While very young johbock stay with their mothers, once they reach maturity they split off in annual groups to head to the mountains, where they join a springer herd. As they get older they jump less and join a herd of elder bock, who are faster runners with curling horns and powerful shoulders. Most young are born to elder bock, but some are born in springer herds which they then never leave. This has been becoming more common as fewer and fewer elder bock herds are left in flat lands in some regions; instead, when springers reach transition they leave the springer herd and wander, often falling prey to hunters or predators.
The spiny jackal is a native egg-laying scavenger/carnivore with a characteristic spotted golden coat and a set of horny spines almost like an echidna along its back. Though its present range is mostly in arid foothills, at some time in the past it was aquatic, with eyes and nostrils well-adapted to just under the surface of the water. Some spiny jackal populations with darker coloring can still be found in the fens and along the banks of the River of Joy, where they engage in dam-building behavior; elsewhere, they tend towards packs. During the Second Republic, it was believed that spiny jackals and horned whales shared a common ancestor.
Yathrib's seas are ruled by its horned whales, which resemble some prehistoric whales from Holy Terra, including the fearsome cachalot sperm whale. The tend to be grouped into three families; the smooth whales have bony ridges beneath their skin, but have no firm armor plates, while the sawback whales have a ridge of horns protruding from their backs. Finally, the great whales - which call to mind the ancient sperm whales - have huge, armored heads. The most fearsome of the great whales is the rhino whale, named for the one or two sharp horns that protrude from its nose.
A fourth family of horned whales are the armored sharks, though only a few scholars understand the relationship between the two groups. Instead, they believe the armored sharks are entirely separate body of creatures, more like dolphins or Old Urth sharks except with a covering of bony plates along their back. The sharp teeth of armored sharks - and the short horns some of their species have - make them a terror of of sailors.
Horned whales lay their young in mermaid's purses; usually, a pod of horned whales has a single egg ground, which they guard jealously.
Other Sea Creatures
There are diverse other sea creatures. The dominant shellfish family are the skeleton crabs, which have segmented bodies like trilobites instead of the single large shells of many Urth crustaceans. One family of skeleton crabs have become terrestrial; colloquially called 'skitterers', they grow to the size of dogs and are a serious pest in some areas. There are also a number of nautiloids; unlike the squids and octopuses of Urth, most have external shells, usually straight spiral cones that give them their common name as 'unicorn squid', though there are examples with curved shells or even no external armor.
Many fishes have four or more small mouth-tentacles; on bottom-dwelling species, they are used to dig through sandy bottoms for food, while in open ocean species they are vestigial or even non-existent. The weeping lamprey - native to the fens of the River of Joy - is a delicacy, and provides a mainstay for many fishers, though horror stories of individuals caught in lamprey nests being devoured by hundreds of the fish are a feature in children's nightmares. Most weeping lampreys are no more than a foot long, but some specimens reach several feet in length.
Several species of schooling fish are referred to communally as 'shoalfish', because they can be mistaken for shoals by those fishermen who have depth-finders. Most shoalfish have a mild flavor and are a mainstay of fishing fleets in the southern Shining Gulf.
The blackfish is a strong-flavored schooling fish with an extremely high oil content, and its fishery is dedicated largely to oil production, though it retains a fishy smell when burned. Blackfish is treated as a poor man's food in most places, though several al-Malik families from Madoc have been purchasing it as a delicacy. Related to the blackfish is the milkfish, so named because of the white oil it carries. Milkfish are precious; when their oil is burned, it gives off a pleasant, buttery smell, and when eaten the flesh of the fish has notes of butterscotch.
Larger sea creatures include the leviathan-fish, a large, deep-dwelling predator with four well-developed mouth-tentacles; some leviathan-fish have been known to attack swimmers. The bearded tuna is a fast swimmer, while the toothfish has small teeth on the inside of its mouth-tentacles, though its flesh is rich and meaty.
Imports and Exotics
Many, perhaps most of the common creatures on Yathrib are imports from Holy Terra or elsewhere. Many of the original share colonists were herders, and so they brought cattle, sheep, and goats with them. Escaped populations of sheep and particularly goats have become substantial presences in the wild; the Moab ibex, for instance, is a long-horned mountain goat descended from once-domesticated populations, while the herds of reindeer in the Boreale are thought to have been released by early settlers to provide food for hunting.
Another major source of some exotic animals was zoos. Iskandretta particularly and the resort cities of Chemosh and the Pearls generally were famous for their menageries during the Second Republic, and during the Fall animal activists released most of the captive animals into the wild. While many died due to native predation, others have prospered, including several species of hyena, the hunting panthers of the Raya jungle, black bears, and more.
Wolves are a problem on Yathrib, as they are on most civilized worlds - and like on most worlds they are not true wolves, but instead predators descended from generations upon generations of feral dogs dating back to the earliest settlements. On Yathrib, the dominant wolf breed is the dingo wolf, which looks very much like the Old Urth dog of the same name, with a sand-colored coat. Mountain populations look more like the red wolves of North America, with darker coloration.
= Windsor Crocodiles
The Windsor crocodile is the same saltwater crocodile found on Old Urth, except larger. Sir Wallace Windsor owned a game preserve in what is now Joyeaux during the waning days of the Second Republic, and he had a fascination with providing clients larger and more dangerous animals to hunt. Two of Yathrib's apex predators can be directly traced to him, and several others have been blamed on him after the fact.
Sir Wallace did - without question - import large numbers of saltwater crocodiles and breed them to be larger and tougher than on Old Urth; now, they are plague in many places on Yathrib, including the Shining Gulf. Windsor crocodiles routinely grow to over ten feet, and twenty-foot crocodiles are not terribly uncommon. Thirty-foot crocodiles are rare but not unheard of, and there are reported monsters that are even larger. Some Genetechs whisper that Sir Wallace was able to turn off the growth limiting on some crocodiles, causing them to never stop growing over the length of their lives.
Pherizia - spitters - are riding lizards common across many of the Known Worlds, and they were imported to Yathrib because of their hardy character in the desert. Many of them now live in the wild, particularly in the Great Desert.
Yathrib had no avians prior to the arrival of humans, and so the settlers introduced them. Songbirds were brought first as pets and then released to the wild, while raptors were used to hunt rodents, for hawking, and for other purposes. There are several ostrich populations - descendants from farmed birds - and a robust set of sea-gulls, though it is far from clear why gulls were brought to the planet.
For centuries, Yathrib was proud of being a planet without pigeons - the Church worked hard to keep them from being imported - but that battle was lost in the late Second Republic.
Sir Wallace Windsor genetically reconstructed the prehistoric megalodon and introduced it to Yathrib's seas, originally in a closed sea-pen off the Isle of Dor. Unsurprisingly, it escaped, and now this toothed monster hunts the seas, albeit in small numbers. Why a man would be so foolish to recreate a giant, whale-hunting shark is a matter of open debate, and to this day 'Windsor's folly' is used as a by-word for ill-conceived expeditions born from pride.
Other Sea Life
There have been several other aquatic imports from Urth and other worlds, including dolphins and sea lions. A variety of tropical fish were seeded on a reef near Gilead for tourist dives during the Second Republic, while a number of lakes and streams were stocked with salmon and trout. Stranger sea life was imported as well, including creatures from the seas of Madoc, Sargasso, and Byzantium Secundus. A number of those creatures escaped when an earthquake cracked open the 'Underwater Aquarium' in St. Paulus-Port; the sunken city is still home to a host of exotic marine species.