SemiaquaticIn biology, semiaquatic refers to various macroorganisms that live regularly in both aquatic and terrestrial environments. When referring to animals, the term describes those that actively spend part of their daily time in water (in which case they can also be called amphibious), or land animals that have spent at least one life stages (e.g. as eggs or larvae) in aquatic environments.
RemoraThe remora (ˈrɛmərə), sometimes called suckerfish, is any of a family (Echeneidae) of ray-finned fish in the order Carangiformes. Depending on species, they grow to long. Their distinctive first dorsal fins take the form of a modified oval, sucker-like organ with slat-like structures that open and close to create suction and take a firm hold against the skin of larger marine animals. The disk is made up of stout, flexible membranes that can be raised and lowered to generate suction.
Marine mammals and sonarThe interactions between marine mammals and sonar have been a subject of debate since the invention of the technology. Active sonar, the transmission equipment used on some ships to assist with submarine detection, is detrimental to the health and livelihood of some marine animals. Research has recently shown that beaked and blue whales are sensitive to mid-frequency active sonar and move rapidly away from the source of the sonar, a response that disrupts their feeding and can cause mass strandings.
Whale fecesWhale feces, the excrement of whales, has a significant role in the ecology of the oceans, and whales have been referred to as "marine ecosystem engineers". Nitrogen released by cetacean species and iron chelate is a significant benefit to the marine food chain in addition to sequestering carbon for long periods. Whale feces can give information on a number of aspects of the health, natural history and ecology of an animal or group as it contains DNA, hormones, toxins, and other chemicals.
AmbulocetusAmbulocetus (Latin ambulare "to walk" + cetus "whale") is a genus of early amphibious cetacean from the Kuldana Formation in Pakistan, roughly 48 or 47 million years ago during the Early Eocene (Lutetian). It contains one species, Ambulocetus natans (Latin natans "swimming"), known solely from a near-complete skeleton. Ambulocetus is among the best-studied of Eocene cetaceans, and serves as an instrumental find in the study of cetacean evolution and their transition from land to sea, as it was the first cetacean discovered to preserve a suite of adaptations consistent with an amphibious lifestyle.
Pygmy killer whaleThe pygmy killer whale (Feresa attenuata) is a poorly known and rarely seen oceanic dolphin. It is the only species in the genus Feresa. It derives its common name from sharing some physical characteristics with the orca also known as the killer whale. It is the smallest cetacean species that has the word "whale" in its common name. Although the species has been known to be extremely aggressive in captivity, this aggressive behavior has not been observed in the wild.
Pygmy hippopotamusThe pygmy hippopotamus or pygmy hippo (Choeropsis liberiensis) is a small hippopotamid which is native to the forests and swamps of West Africa, primarily in Liberia, with small populations in Sierra Leone, Guinea, and Ivory Coast. It has been extirpated from Nigeria. The pygmy hippo is reclusive and nocturnal. It is one of only two extant species in the family Hippopotamidae, the other being its much larger relative, the common hippopotamus (Hippopotamus amphibius) or Nile hippopotamus.
