Couch's spadefoot toad or Couch's spadefoot (''Scaphiopus couchii)'' is a

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

family Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...

Scaphiopodidae). The

specific epithet In taxonomy, binomial nomenclature ("two-term naming system"), also called nomenclature ("two-name naming system") or binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, bot ...

''couchii'' is in honor of American naturalist

Darius Nash Couch Darius Nash Couch (July 23, 1822 – February 12, 1897) was an American soldier, businessman, and naturalist. He served as a career U.S. Army officer during the Mexican–American War, the Second Seminole War, and as a general officer in the U ...

, who collected the first specimen while on a personal expedition to northern

Mexico Mexico (Spanish: México), officially the United Mexican States, is a country in the southern portion of North America. It is bordered to the north by the United States; to the south and west by the Pacific Ocean; to the southeast by Guatema ...

to collect plant, mineral, and animal specimens for the

Smithsonian Institution The Smithsonian Institution ( ), or simply the Smithsonian, is a group of museums and education and research centers, the largest such complex in the world, created by the U.S. government "for the increase and diffusion of knowledge". Founded ...

Description

Unlike other toads which have horizontal pupils, spadefoot toads have vertical pupils. On the underside of the hind foot is a hard, dark "spade" that gives spadefoot toads their name. These creatures can grow to be 3.5" in length. These "spades" are used by the toads to burrow into the ground to prevent water loss and hide from predators. There are two spadefoot species in the Sonoran Desert of Arizona and California. Couch's spadefoot toad (''Scaphiopus couchi'') has a sickle-shaped "spade", whereas the western spadefoot toad (''

Spea hammondii ''Spea hammondii'', also known as the western spadefoot, western spadefoot toad, Hammond's spadefoot, or Hammond's spadefoot toad, is a species of amphibian in the family Scaphiopodidae. It is found in western California (USA) and northwester ...

'') has a rounded "spade". Spadefoots are not true toads and should therefore simply be called spadefoots.

Distribution

Couch's spadefoot toad is native to the

United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territorie ...

southwest of southeastern Colorado and central Oklahoma, northern

and the Baja peninsula. They can be found throughout the

Sonoran Desert The Sonoran Desert ( es, Desierto de Sonora) is a desert in North America and ecoregion that covers the northwestern Mexican states of Sonora, Baja California, and Baja California Sur, as well as part of the southwestern United States (in Arizona ...

, which includes parts of southern

Arizona Arizona ( ; nv, Hoozdo Hahoodzo ; ood, Alĭ ṣonak ) is a state in the Southwestern United States. It is the 6th largest and the 14th most populous of the 50 states. Its capital and largest city is Phoenix. Arizona is part of the Fou ...

and

California California is a U.S. state, state in the Western United States, located along the West Coast of the United States, Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the List of states and territori ...

Mating and reproduction

Water is a necessary medium for the

fertilization Fertilisation or fertilization (see spelling differences), also known as generative fertilisation, syngamy and impregnation, is the fusion of gametes to give rise to a new individual organism or offspring and initiate its development. Proce ...

of spadefoot

egg An egg is an organic vessel grown by an animal to carry a possibly fertilized egg cell (a zygote) and to incubate from it an embryo within the egg until the embryo has become an animal fetus that can survive on its own, at which point the a ...

s, and once the eggs hatch, water also provides a place for

tadpoles A tadpole is the larval stage in the biological life cycle of an amphibian. Most tadpoles are fully aquatic, though some species of amphibians have tadpoles that are terrestrial. Tadpoles have some fish-like features that may not be found in ...

to mature to the adult stage. Because of the importance of water, spadefoots are active during the wet season spring and summer in the

Northern Hemisphere The Northern Hemisphere is the half of Earth that is north of the Equator. For other planets in the Solar System, north is defined as being in the same celestial hemisphere relative to the invariable plane of the solar system as Earth's Nort ...

), and remain underground during the dry season (fall and winter). When a summer thunderstorm arrives, the male toads emerge from underground and look for pools of rainwater. When they find water, the males produce a

mating call A mating call is the auditory signal used by animals to attract mates. It can occur in males or females, but literature is abundantly favored toward researching mating calls in females. In addition, mating calls are often the subject of mate choic ...

that attracts female toads. New research has shown that females tend to be more attracted to bright-colored males over their dark-colored peers. Thus creating a new aspect in their determination of the male's size and condition.Vásquez, Tatiana; Pfennig, Karin S. (2007). "Looking on the bright side: females prefer coloration indicative of male size and condition in the sexually dichromatic spadefoot toad, ''Scaphiopus couchii'' ". ''Behavioral Ecology and Sociobiology'' 62: 127–135.https://www.jstor.org/stable/25511675?seq=1#page_scan_tab_contents Because the pools of water may be short-lived, mating occurs the first night after rainfall begins. During reproduction, the male mounts the female and releases

sperm Sperm is the male reproductive cell, or gamete, in anisogamous forms of sexual reproduction (forms in which there is a larger, female reproductive cell and a smaller, male one). Animals produce motile sperm with a tail known as a flagellum, whi ...

to fertilize the eggs, which are deposited in the pools of water in the form of a floating mass. The eggs hatch into tadpoles, which quickly mature into adults. They must reach this stage before the pool of water evaporates, and thus they sometimes mature in as little as 9 days after the eggs are laid. Western spadefoot toads take longer to mature (at least three weeks). The small pools of water are warmed by the

sun The Sun is the star at the center of the Solar System. It is a nearly perfect ball of hot plasma, heated to incandescence by nuclear fusion reactions in its core. The Sun radiates this energy mainly as light, ultraviolet, and infrared radi ...

, which speeds up the growth of the tadpoles. Tadpoles will eat a variety of foods, such as small

insect Insects (from Latin ') are pancrustacean hexapod invertebrates of the class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body ( head, thorax and abdomen), three pairs ...

s near the pool and

algae Algae (; singular alga ) is an informal term for a large and diverse group of photosynthetic eukaryotic organisms. It is a polyphyletic grouping that includes species from multiple distinct clades. Included organisms range from unicellular mic ...

, which they scrape off rocks. They also filter

microorganism A microorganism, or microbe,, ''mikros'', "small") and ''organism'' from the el, ὀργανισμός, ''organismós'', "organism"). It is usually written as a single word but is sometimes hyphenated (''micro-organism''), especially in olde ...

s from the water as it is passed over their

gills A gill () is a respiratory organ that many aquatic organisms use to extract dissolved oxygen from water and to excrete carbon dioxide. The gills of some species, such as hermit crabs, have adapted to allow respiration on land provided they are ...

. Tadpoles gather in wriggling masses, stir up the muck on the bottom of the pool, and filter out the organic nutrients. Unlike most tadpoles, which are exclusively

herbivores A herbivore is an animal anatomically and physiologically adapted to eating plant material, for example foliage or marine algae, for the main component of its diet. As a result of their plant diet, herbivorous animals typically have mouthpart ...

and

filter feeders Filter feeders are a sub-group of suspension feeding animals that feed by straining suspended matter and food particles from water, typically by passing the water over a specialized filtering structure. Some animals that use this method of feedin ...

, spadefoot tadpoles are

omnivores An omnivore () is an animal that has the ability to eat and survive on both plant and animal matter. Obtaining energy and nutrients from plant and animal matter, omnivores digest carbohydrates, protein, fat, and fiber, and metabolize the nutri ...

. They also eat dead

s and tadpoles, as well as

fairy shrimp Anostraca is one of the four orders of crustaceans in the class Branchiopoda; its members are referred to as fairy shrimp. They live in vernal pools and hypersaline lakes across the world, and they have even been found in deserts, ice-covered mou ...

References

External links

Animal Diversity Web: ''Scaphiopus couchii''
{{Taxonbar, from=Q504971 Scaphiopus Amphibians described in 1854 Amphibians of Mexico Amphibians of the United States Taxa named by Spencer Fullerton Baird