Results for “sp.”

unculus

Horny projection originating from a single cell of the epidermis found on the disc of Garra sp. and catfishes of the family Sisoridae, for example.

unisexual

Fish species of which all individuals are the same gender.

vertebra

Any of the bony or cartilaginous segments comprising the spinal column.

Used in 33 profiles

vertebrate

An organism possessing a backbone or spinal column.

Used in 48 profiles

vicariance

Separation or division of a population by a geographic barrier, such as a mountain or body of water, resulting in evolution into new varieties or species.

vicariant

Used in reference to any of several closely related species, variants, etc., each of which exists in a distinct geographical area but are assumed to have originated from a single population that became dispersed by geological events; of or relating to such an event.

wadi

Arabic term used to refer to a valley, stream-bed or other watercourse that only holds water during the rainy season. Often associated with oases and normally applied only in certain Arabic-speaking countries.

Used in 1 profile

Wallace's line

Hypothetical line, proposed by British naturalist Alfred Russel Wallace that marks the transitional boundary between the Oriental and Australian zoogeographical regions. It passes between the islands of Borneo and Sulawesi to its northern limit, Bali and Lombok to the south. To the west of the line organisms descended from Asiatic ancestors predominate, while to the east there exist species of both Asian and Australian origin.

Used in 1 profile

Western Ghats

Mountain range extending southwards down the western side of India from the borders of Gujarat and Maharashtra states, through Maharashtra, Goa, Karnataka, Tamil Nadu and Kerala as far as Kanyakumari district in Tamil Nadu. The Ghats are a UNESCO World Heritage Site and represent one of the eight hottest hotspots of biological diversity in the world, and is home to a number of endemic fish species.

Used in 44 profiles

wet/dry filter

Type of filter normally placed under the aquarium, and often home-made. The basic premise is that water trickles vertically downards through separated compartments containing mechanical and biological filter media with spaces inbetween so that it is also exposed to the air briefly. It then collects in a base chamber or sump from where it is pumped back to the main aquarium. There are many commercial designs available, some of which are more effective than others. Not popular in marine reef aquaria due to the associated accumulation of nitrates as by-product.

white worm

Vernacular name for the annelid worm Enchytraeus albidus Henle, 1937, a species commonly cultured by aquarists for use as live fish food.

Used in 8 profiles

yolk sac

A membranous sac containing yolk attached to the ventral surface of embryos and early larvae in some fishes. Retained for a period post-hatching in those species which form yolk sac larvae.

Used in 221 profiles

yolk sac larva

Post-hatching larval stage occurring in many fish species whereby the yolk sac remains attached to the ventral surface for a period. The larva does not feed normally until the yolk is fully-absorbed.

zoea

Early, planktonic larval form common in decapod crustaceans, e.g., crabs, characterised by possession of well-developed abdominal appendages and one or more spines on the carapace.

zoobenthos

Those animal species dwelling on or in the bottom of a water body.

Used in 9 profiles

unicuspid

Having a single point or cusp. Commonly used in reference to teeth of such form.

Used in 15 profiles