Poeciliopsis occidentalis sonorensis, commonly known as the Yaqui topminnow

Fundulidae

Fundulidae is the family of topminnows and North American killifishes. The 46 species are native to North America as far south as Yucatan, and to the islands of Bermuda and Cuba, occurring in both freshwater and marine environments....

, is a species of fish

Fish

Fish are a paraphyletic group of organisms that consist of all gill-bearing aquatic vertebrate animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish, as well as various extinct related groups...

 native to the American southwest and Northern Mexico

Mexico

The United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...

.

Description

The Yaqui topminnow has an elongated and slightly curved body. Males are rarely over 25 mm (1 in) and they are smaller than females, which can sometimes be 50 mm (2 in) P.o. sonoriensis can be distinguished from P.o. occidentalis by their superior mouth, longer snout, and the lateral bands of the female, which rarely develop before the bases of the pelvic fins

Biology

The topminnow has a lifespan that is determined by when they reach sexual maturity

Sexual maturity

Sexual maturity is the age or stage when an organism can reproduce. It is sometimes considered synonymous with adulthood, though the two are distinct...

, which may only be a few weeks. Their breeding season

Breeding season

The breeding season is the most suitable season, usually with favourable conditions and abundant food and water, for breeding among some wild animals and birds . Species with a breeding season have naturally evolved to have sexual intercourse during a certain time of year in order to achieve the...

 can last from January through August. The males places spermatophore

Spermatophore

A spermatophore or sperm ampulla is a capsule or mass created by males of various animal species, containing spermatozoa and transferred in entirety to the female's ovipore during copulation...

s into the female. The females can carry two brood

Brood

Brood may refer to:* Brood, a collective term for offspring* Brooding, the incubation of bird eggs by their parents* Brood , the young of a beehive*Brood: to think deeply about something, often in a dark or melancholy manner....

s at once, and their brood size can be from 6 to 49 young with a 12-15 day gestation

Gestation

Gestation is the carrying of an embryo or fetus inside a female viviparous animal. Mammals during pregnancy can have one or more gestations at the same time ....

 period.
This species can be found living at lowland and some upland streams, they usually live near the surface in shallow water and they are often associated with aquatic vegetation. Topminnows are omnivorous, and usually eat detritus

Detritus

Detritus is a biological term used to describe dead or waste organic material.Detritus may also refer to:* Detritus , a geological term used to describe the particles of rock produced by weathering...

, algae

Algae

Algae are a large and diverse group of simple, typically autotrophic organisms, ranging from unicellular to multicellular forms, such as the giant kelps that grow to 65 meters in length. They are photosynthetic like plants, and "simple" because their tissues are not organized into the many...

, and aquatic

Aquatic animal

An aquatic animal is an animal, either vertebrate or invertebrate, which lives in water for most or all of its life. It may breathe air or extract its oxygen from that dissolved in water through specialised organs called gills, or directly through its skin. Natural environments and the animals that...

 invertebrates.