Creaser's mud turtle (''Kinosternon creaseri'') is a

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

mud turtle ''Kinosternon'' is a genus of small aquatic turtles from the Americas known commonly as mud turtles. Geographic range They are found in the United States, Mexico, Central America, and South America. The greatest species richness is in Mexico, ...

in the

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

Kinosternidae The Kinosternidae are a family of mostly small turtles that includes the mud turtles and musk turtles. The family contains 25 species within four genera, but taxonomic reclassification is an ongoing process, so many sources vary on the exact num ...

. The species is

endemic Endemism is the state of a species being found only in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also foun ...

to the

Yucatán Peninsula The Yucatán Peninsula ( , ; ) is a large peninsula in southeast Mexico and adjacent portions of Belize and Guatemala. The peninsula extends towards the northeast, separating the Gulf of Mexico to the north and west of the peninsula from the C ...

in southeastern

Mexico Mexico, officially the United Mexican States, is a country in North America. It is the northernmost country in Latin America, and borders the United States to the north, and Guatemala and Belize to the southeast; while having maritime boundar ...

. The

specific name Specific name may refer to: * in Database management systems, a system-assigned name that is unique within a particular database In taxonomy, either of these two meanings, each with its own set of rules: * Specific name (botany), the two-part (bino ...

, ''creaseri'', is in honor of

American American(s) may refer to: * American, something of, from, or related to the United States of America, commonly known as the "United States" or "America" ** Americans, citizens and nationals of the United States of America ** American ancestry, p ...

zoologist Zoology ( , ) is the scientific study of animals. Its studies include the structure, embryology, classification, habits, and distribution of all animals, both living and extinct, and how they interact with their ecosystems. Zoology is one ...

Edwin Phillip Creaser (1907–1981).

Geographic range

''K. creaseri'' is found in the Mexican states of

Campeche Campeche, officially the Free and Sovereign State of Campeche, is one of the 31 states which, with Mexico City, make up the Administrative divisions of Mexico, 32 federal entities of Mexico. Located in southeast Mexico, it is bordered by the sta ...

Quintana Roo Quintana Roo, officially the Free and Sovereign State of Quintana Roo, is one of the 31 states which, along with Mexico City, constitute the 32 administrative divisions of Mexico, federal entities of Mexico. It is divided into municipalities of ...

, and Yucatan. www.reptile-database.org. A 1988 study found that the densest population occurred in Quintana Roo, as the state had been subjected to less deforestation than Campeche or Yucatán.

Habitat

The preferred natural

habitat In ecology, habitat refers to the array of resources, biotic factors that are present in an area, such as to support the survival and reproduction of a particular species. A species' habitat can be seen as the physical manifestation of its ...

of ''K. creaseri'' is small temporary pools of water in

forest A forest is an ecosystem characterized by a dense ecological community, community of trees. Hundreds of definitions of forest are used throughout the world, incorporating factors such as tree density, tree height, land use, legal standing, ...

shrubland Shrubland, scrubland, scrub, brush, or bush is a plant community characterized by vegetation dominance (ecology), dominated by shrubs, often also including grasses, herbaceous plant, herbs, and geophytes. Shrubland may either occur naturally o ...

, and freshwater

wetlands A wetland is a distinct semi-aquatic ecosystem whose groundcovers are flooded or saturated in water, either permanently, for years or decades, or only seasonally. Flooding results in oxygen-poor ( anoxic) processes taking place, especially ...

, although they may occasionally be found in permanent pools of water as well. These temporary pools of water are generally devoid of fish.

Description

The species is of average size for the genus ''

Kinosternon ''Kinosternon'' is a genus of small aquatic turtles from the Americas known commonly as mud turtles. Geographic range They are found in the United States, Mexico, Central America, and South America. The greatest species richness is in Mexico, a ...

''. Males are slightly larger than females. The average carapace length of males is 11.5 cm, while female average carapace length is 10.7 cm. The largest male on record had a carapace length of 12.5 cm. Males can also be distinguished from females by their longer tails. The species can be identified by its distinctive, strongly hooked beak. This is likely not an adaption for feeding, but for aggression. Although the species can be confused with the

scorpion mud turtle The scorpion mud turtle or Tabasco mud turtle (''Kinosternon scorpioides'') is a species of mud turtle in the family Kinosternidae. It is found in Mexico, Central and South America. Description The scorpion mud turtle is a medium to large kin ...

, Creaser's mud turtle can be distinguished from the latter by its more pungent musk and much more aggressive behaviour; while scorpion mud turtles almost always retract into their shells upon capture, both adult and hatchling Creaser's mud turtles will attempt to bite when caught. Additionally, Creaser's mud turtle has a curved (as opposed to straight) seam between the scutes of the plastral hindlobe and those of the fixed mid-portion of the plastron. Its

sister species In phylogenetics, a sister group or sister taxon, also called an adelphotaxon, comprises the closest relative(s) of another given unit in an evolutionary tree. Definition The expression is most easily illustrated by a cladogram: Taxon A and ...

is the Tabasco mud turtle (''K. acutum''), which Creaser's mud turtle can be also be confused with. File:Kinosternon creaseri 4662365.jpg,

Yucatán Yucatán, officially the Free and Sovereign State of Yucatán, is one of the 31 states which, along with Mexico City, constitute the 32 federal entities of Mexico. It comprises 106 separate municipalities, and its capital city is Mérida. ...

File:Kinosternon creaseri 4662285.jpg, Yucatán File:Kinosternon creaseri 4662466.jpg, Yucatán,

plastron The turtle shell is a shield for the ventral and dorsal parts of turtles (the Order (biology), order Testudines), completely enclosing all the turtle's vital organs and in some cases even the head. It is constructed of modified bony elements such ...

File:Kinosternon creaseri 11987906.jpg,

Geographic variation

There is significant geographic variation in the species. For example, Quintana Roo specimens have generally dark coloured shells, with lighter coloured heads and pale yellow necks. This is in contrast to elsewhere on the Yucatán peninsula, where shell colour is lighter and the colour of the neck and even parts of the foreleg may be brighter yellow. Additionally, plastron morphology of Yucatán specimens differ noticeably from Campeche and Quintana Roo specimens.

Behavior

''K. creaseri'' aestivates most of the year, during which they are buried underground, and are only active during the rainy season, which occurs in June through October. Hatchlings of this species rarely bask in captivity, unlike the similar looking

, which basks frequently as hatchlings.

Diet

The species is primarily carnivorous, with observations of their feces showing they are composed mainly insect parts and snail shells, although palm seeds were also occasionally present. Kinosternon creaseri 416914500

Aggression

The species is highly aggressive for a mud turtle, and both adults and hatchlings will viciously attempt to bite upon capture. Additionally, the strongly hooked beak that makes this species distinctive is likely not an adaptation for feeding, but for aggression. The edges of the carapace in individuals are often eroded, likely from aggressive interactions between conspecifics. Adult males are especially aggressive; if multiple turtles are placed in the same container as an adult male, bite marks soon appear on their shells. Even hatchlings will aggressively bite each other.

Reproduction

''K. creaseri'' is

oviparous Oviparous animals are animals that reproduce by depositing fertilized zygotes outside the body (i.e., by laying or spawning) in metabolically independent incubation organs known as eggs, which nurture the embryo into moving offsprings kno ...

Clutch A clutch is a mechanical device that allows an output shaft to be disconnected from a rotating input shaft. The clutch's input shaft is typically attached to a motor, while the clutch's output shaft is connected to the mechanism that does th ...

size is small, only one or two eggs, although each female lays more than one clutch per year. However, this species lays some of the largest eggs proportionate to the mother's body mass of any kinosternine species, only rivalled by Central-American, white-lipped, and

Tabasco mud turtle The Tabasco mud turtle (''Kinosternon acutum''), commonly known as pochitoque in Tabasco, Mexico, is a small turtle which belongs to the family Kinosternidae. It can be found in central Veracruz, Tabasco, northern Guatemala and Belize. This turt ...

s. Sex of the hatchlings is determined by temperature.

Growth

Juveniles grow rapidly, with males likely growing faster than females by the second year. In captivity, 2 year old turtles that were caught early in their first year of life in the wild had grown to 8.4-9.3 cm (carapace length). Females reach maturity at around 10–15 years of age.

Conservation

This species is threatened by deforestation (increasing evaporation thereby reducing the number of pools of water), as well as the use of wet lowland environments for agriculture.