Bradfield's Namib day gecko (''Rhoptropus bradfieldi'') 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 ...

lizard Lizards are a widespread group of squamate reptiles, with over 7,000 species, ranging across all continents except Antarctica, as well as most oceanic island chains. The group is paraphyletic since it excludes the snakes and Amphisbaenia alt ...

in the

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 ...

Gekkonidae Gekkonidae (the common geckos) is the largest family of geckos, containing over 950 described species in 64 genera. Members of the Gekkonidae comprise many of the most widespread gecko species, including house geckos (''Hemidactylus''), tokay ge ...

. The species is endemic to

Namibia Namibia (, ), officially the Republic of Namibia, is a country in Southern Africa. Its western border is the Atlantic Ocean. It shares land borders with Zambia and Angola to the north, Botswana to the east and South Africa to the south and ea ...

. This species was first described in 1935 by the British-born, South African zoologist John Hewitt, who gave it the name ''Rhoptropus bradfieldi'' in honour of the South African naturalist and collector R.D. Bradfield (1882–1949).

Description

''Rhoptropus bradfieldi'' has a maximum snout-to-vent length (SVL) of , Branch, Bill (2004). ''Field Guide to Snakes and other Reptiles of Southern Africa''. Third Revised Edition, Second Impression. Sanibel Island, Florida: Ralph Curtis Books. 399 pp. . (''Rhoptropus bradfieldi'', p. 268 + Plate 92). and a total length (including tail) of about . The dorsal surface is greyish-brown, indistinctly barred and dappled, and the ventral surface is bluish-grey. There are eleven scansors (specialist structures for adhesion) under the middle toe. This gecko is similar in appearance to the Namib day gecko (''Rhoptropus afer''), but that species is slightly smaller, has bright yellow underparts and only six scansors under the middle digit. The difference in scansor number between the two species, and the much shorter

seta In biology, setae (singular seta ; from the Latin word for "bristle") are any of a number of different bristle- or hair-like structures on living organisms. Animal setae Protostomes Annelid setae are stiff bristles present on the body. Th ...

e from which the scansors are formed in ''R. afer'', are reflected in different lifestyles; ''R. bradfieldi'', with more-adhesive feet, is a crevice-dweller with a slow, climbing lifestyle, while ''R. afer'' is much more terrestrial, running rapidly on the ground and jumping from rock to rock.

Distribution and habitat

''Rhoptropus bradfieldi'' is

endemic Endemism is the state of a species being found 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 found elsew ...

to Namibia. Its typical habitat is rocks and boulders in arid regions of the

Namib Desert The Namib ( ; pt, Namibe) is a coastal desert in Southern Africa. The name is of Khoekhoegowab origin and means "vast place". According to the broadest definition, the Namib stretches for more than along the Atlantic coasts of Angola, Namib ...

Ecology

''Rhoptropus bradfieldi'' is a diurnal lizard and is an

ambush predator Ambush predators or sit-and-wait predators are carnivorous animals that capture or trap prey via stealth, luring or by (typically instinctive) strategies utilizing an element of surprise. Unlike pursuit predators, who chase to capture prey us ...

of small

arthropod Arthropods (, (gen. ποδός)) are invertebrate animals with an exoskeleton, a Segmentation (biology), segmented body, and paired jointed appendages. Arthropods form the phylum Arthropoda. They are distinguished by their jointed limbs and Arth ...

s such as

ant Ants are eusocial insects of the family Formicidae and, along with the related wasps and bees, belong to the order Hymenoptera. Ants evolved from vespoid wasp ancestors in the Cretaceous period. More than 13,800 of an estimated total of 22 ...

moth Moths are a paraphyletic group of insects that includes all members of the order Lepidoptera that are not butterflies, with moths making up the vast majority of the order. There are thought to be approximately 160,000 species of moth, many of w ...

s, and

beetle Beetles are insects that form the order Coleoptera (), in the superorder Endopterygota. Their front pair of wings are hardened into wing-cases, elytra, distinguishing them from most other insects. The Coleoptera, with about 400,000 describ ...

s. Its body is maintained at a high but steady temperature while it is active. It has a low

field metabolic rate Field metabolic rate (FMR) refers to a measurement of the metabolic rate of a free-living animal. Method Measurement of the Field metabolic rate is made using the doubly labeled water method, although alternative techniques, such as monitoring ...

, about 26% of that of other desert lizards, but a relatively high water intake, which it probably fulfils from the fogs that often occur near the coast.

Reproduction

''R. bradfieldi'' is

oviparous Oviparous animals are animals that lay their eggs, with little or no other embryonic development within the mother. This is the reproductive method of most fish, amphibians, most reptiles, and all pterosaurs, dinosaurs (including birds), and ...

Clutch A clutch is a mechanical device that engages and disengages power transmission, especially from a drive shaft to a driven shaft. In the simplest application, clutches connect and disconnect two rotating shafts (drive shafts or line shafts). ...

size is two eggs, and each egg measures about .

Description

Distribution and habitat

Ecology

Reproduction

References

Further reading