''Causus defilippii'', commonly known as snouted night adder, is a

species In biology, a species is the basic unit of Taxonomy (biology), 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 ...

of snake in the

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

Viperidae The Viperidae (vipers) are a family of snakes found in most parts of the world, except for Antarctica, Australia, Hawaii, Madagascar, and various other isolated islands. They are venomous and have long (relative to non-vipers), hinged fangs t ...

. The species 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 els ...

East East or Orient is one of the four cardinal directions or points of the compass. It is the opposite direction from west and is the direction from which the Sun rises on the Earth. Etymology As in other languages, the word is formed from the fa ...

and

Southern Africa Southern Africa is the southernmost subregion of the African continent, south of the Congo and Tanzania. The physical location is the large part of Africa to the south of the extensive Congo River basin. Southern Africa is home to a number ...

. Although its venom is nonlethal to humans, it is still considered medically significant. There are no recognized subspecies. Mallow D,

Ludwig D Ludwig may refer to: People and fictional characters * Ludwig (given name), including a list of people and fictional characters * Ludwig (surname), including a list of people * Ludwig Ahgren, or simply Ludwig, American YouTube live streamer and c ...

, Nilson G (2003). ''True Vipers: Natural History and Toxinology of Old World Vipers''. Malabar, Florida: Krieger Publishing Company. 359 pp. . Spawls S, Branch B (1995). ''The Dangerous Snakes of Africa''. Dubai: Oriental Press / Ralph Curtis Books. 192 pp. .''

Etymology

The specific name, ''defilippii'', is in honor of

Italian Italian(s) may refer to: * Anything of, from, or related to the people of Italy over the centuries ** Italians, an ethnic group or simply a citizen of the Italian Republic or Italian Kingdom ** Italian language, a Romance language *** Regional Ita ...

zoologist Zoology ()The pronunciation of zoology as is usually regarded as nonstandard, though it is not uncommon. is the branch of biology that studies the animal kingdom, including the structure, embryology, evolution, classification, habits, and ...

Filippo De Filippi. Beolens, Bo; Watkins, Michael; Grayson, Michael (2011). ''The Eponym Dictionary of Reptiles''. Baltimore: Johns Hopkins University Press. xiii + 296 pp. . (''Causus defilippii'', p. 67).

Description

The average total length (including tail) of ''C. defilippii'' is , rarely exceeding . The head is short and wide, and the snout is prominent, pointed and upturned. The

rostral Rostral may refer to: Anatomy * Rostral (anatomical term), situated toward the oral or nasal region * Rostral bone, in ceratopsian dinosaurs * Rostral organ, of certain fish * Rostral scale, in snakes and scaled reptiles Other uses * Rostral col ...

is large. The eyes are medium-sized. The circumorbital ring consists of 1–2

preocular scales In scaled reptiles, the ocular scales are those forming the margin of the eye.Wright AH, Wright AA. 1957. ''Handbook of Snakes''. Comstock Publishing Associates (7th printing, 1985). 1105 pp. . The name originates from the term ''oculus'' which ...

, 1–2 postoculars and 1–2

suboculars In scaled reptiles, the ocular scales are those forming the margin of the eye.Wright AH, Wright AA. 1957. ''Handbook of Snakes''. Comstock Publishing Associates (7th printing, 1985). 1105 pp. . The name originates from the term ''oculus'' which ...

that separate the eye from the

supralabials In reptiles, the supralabial scales, also called upper-labials, are those scales that border the mouth opening along the upper jaw. They do not include the median scaleWright AH, Wright AA. 1957. Handbook of Snakes. Comstock Publishing Associates ...

. There are a total of 6–7 supralabials and 7–10

sublabials In reptiles, the sublabial scales, also called lower-labials or infralabials, are those scales that border the mouth opening along the lower jaw. They do not include the median scaleWright AH, Wright AA. 1957. ''Handbook of Snakes''. Comstock Publi ...

. The first 3–4 sublabials are in contact with the anterior

chin shields Chin shields or chinshields, genials scales on a snake are scales found on the underside of the snake's head towards the anterior and touching the lower labial scales. Chin shields to the front of the snake (towards the snout) are called anterior c ...

. The posterior chin shields are very small and indistinguishable from other posterior scales. The

temporal scales Temporal may refer to: Entertainment * Temporal (band), an Australian metal band * ''Temporal'' (Radio Tarifa album), 1997 * ''Temporal'' (Love Spirals Downwards album), 2000 * ''Temporal'' (Isis album), 2012 * ''Temporal'' (video game), a 200 ...

number 2+3, sometimes 2+4, and rarely 1+2. Midbody there are 16–18 rows of weakly keeled

dorsal scales In snakes, the dorsal scales are the longitudinal series of plates that encircle the body, but do not include the ventral scales. Campbell JA, Lamar WW (2004). ''The Venomous Reptiles of the Western Hemisphere''. Ithaca and London: Comstock Publis ...

that have a velvety appearance. There are 108–128

ventral scales In snakes, the ventral scales or gastrosteges are the enlarged and transversely elongated scales that extend down the underside of the body from the neck to the anal scale. When counting them, the first is the anteriormost ventral scale that conta ...

: rarely more than 117 in males, or less than 118 in females. The

anal scale Anal may refer to: Related to the anus *Related to the anus of animals: ** Anal fin, in fish anatomy ** Anal vein, in insect anatomy ** Anal scale, in reptile anatomy *Related to the human anus: ** Anal sex, a type of sexual activity involving ...

is single. The divided

subcaudals In snakes, the subcaudal scales are the enlarged plates on the underside of the tail.Wright AH, Wright AA. 1957. Handbook of Snakes. Comstock Publishing Associates (7th printing, 1985). 1105 pp. . These scales may be either single or divided (pair ...

number 10–19: seldom less than 14 in males, or more than 15 in females. The color pattern consists of a light brown, pinkish brown to gray or grayish green ground color, overlaid with a series of 20–30 crescent-shaped dark markings that run down the back. However, these marking may be indistinct. The head has a characteristic V-shaped marking with the apex on the

frontal plate Frontal scale refers to the scales of a reptile which lie in the general region of the forehead of a snake, more specifically between the eyes and to the anterior of this area. These are analogous to the ''frontal bone'' on a human which correspo ...

. There is also an oblique dark streak present behind the eye. The belly is yellowish while, uniformly colored or with scattered small grayish brown spots. Juvenile specimens are commonly a glossy black or gray.

Geographic range

The snouted night adder is found in

Tanzania Tanzania (; ), officially the United Republic of Tanzania ( sw, Jamhuri ya Muungano wa Tanzania), is a country in East Africa within the African Great Lakes region. It borders Uganda to the north; Kenya to the northeast; Comoro Islands ...

and the

Democratic Republic of the Congo The Democratic Republic of the Congo (french: République démocratique du Congo (RDC), colloquially "La RDC" ), informally Congo-Kinshasa, DR Congo, the DRC, the DROC, or the Congo, and formerly and also colloquially Zaire, is a country in ...

southward through

Malawi Malawi (; or aláwi Tumbuka: ''Malaŵi''), officially the Republic of Malawi, is a landlocked country in Southeastern Africa that was formerly known as Nyasaland. It is bordered by Zambia to the west, Tanzania to the north and northe ...

Zambia Zambia (), officially the Republic of Zambia, is a landlocked country at the crossroads of Central, Southern and East Africa, although it is typically referred to as being in Southern Africa at its most central point. Its neighbours are ...

Mozambique Mozambique (), officially the Republic of Mozambique ( pt, Moçambique or , ; ny, Mozambiki; sw, Msumbiji; ts, Muzambhiki), is a country located in southeastern Africa bordered by the Indian Ocean to the east, Tanzania to the north, Mala ...

, and

Zimbabwe Zimbabwe (), officially the Republic of Zimbabwe, is a landlocked country located in Southeast Africa, between the Zambezi and Limpopo Rivers, bordered by South Africa to the south, Botswana to the south-west, Zambia to the north, and Mozam ...

South Africa South Africa, officially the Republic of South Africa (RSA), is the southernmost country in Africa. It is bounded to the south by of coastline that stretch along the South Atlantic and Indian Oceans; to the north by the neighbouring count ...

and

Eswatini Eswatini ( ; ss, eSwatini ), officially the Kingdom of Eswatini and formerly named Swaziland ( ; officially renamed in 2018), is a landlocked country in Southern Africa. It is bordered by Mozambique to its northeast and South Africa to its ...

. The

type locality Type locality may refer to: * Type locality (biology) * Type locality (geology) See also * Local (disambiguation) * Locality (disambiguation) {{disambiguation ...

was originally listed as "Buenos Ayres", obviously a mistake. It was restricted by

Broadley Broadley is a surname. Notable people with the surname include: *Alexander Meyrick Broadley (1847–1916), British historian, author, and barrister *Denise Broadley (1913–2007), British artist *Donald George Broadley (1932–2016), British herpet ...

(1971) to Africa, Puku.

Habitat

''C. defilippii'' occurs in moist and dry

savanna A savanna or savannah is a mixed woodland-grassland (i.e. grassy woodland) ecosystem characterised by the trees being sufficiently widely spaced so that the canopy does not close. The open canopy allows sufficient light to reach the ground to ...

, coastal thickets, and

forest A forest is an area of land dominated by trees. Hundreds of definitions of forest are used throughout the world, incorporating factors such as tree density, tree height, land use, legal standing, and ecological function. The United Nations' ...

s from sea level to around altitude.Spawls S, Howell K, Drewes R, Ashe J (2004). ''A Field Guide To The Reptiles Of East Africa''. London: A & C Black Publishers Ltd. 543 pp. . It favors moist surroundings, but has also been found in dry areas on rocky hillsides and escarpments.

Behavior

The snouted night adder is generally

nocturnal Nocturnality is an ethology, animal behavior characterized by being active during the night and sleeping during the day. The common adjective is "nocturnal", versus diurnality, diurnal meaning the opposite. Nocturnal creatures generally have ...

, but not entirely. It is mostly terrestrial, but sometimes climbs into low vegetation in pursuit of

frog A frog is any member of a diverse and largely carnivorous group of short-bodied, tailless amphibians composing the order Anura (ανοὐρά, literally ''without tail'' in Ancient Greek). The oldest fossil "proto-frog" '' Triadobatrachus'' is ...

s, and is also a good swimmer. When not basking, it remains hidden in ground cover, brush piles, and in holes. If disturbed, it inflates itself and hisses. It is slow-moving for the most part, but can strike quickly. In captivity, however, it soon becomes tame and unwilling to strike.

Venom

Little is known about the venom of ''C. defilippii'', but the symptoms described in the few existing case histories include rapid swelling, fever, sometimes intense pain, and occasionally

lymphadenopathy Lymphadenopathy or adenopathy is a disease of the lymph nodes, in which they are abnormal in size or consistency. Lymphadenopathy of an inflammatory type (the most common type) is lymphadenitis, producing swollen or enlarged lymph nodes. In cl ...

. The swelling usually subsided after 2–3 days, and there have not been any reports of

necrosis Necrosis () is a form of cell injury which results in the premature death of cells in living tissue by autolysis. Necrosis is caused by factors external to the cell or tissue, such as infection, or trauma which result in the unregulated dig ...

. Currently, there is no

antivenin Antivenom, also known as antivenin, venom antiserum, and antivenom immunoglobulin, is a specific treatment for envenomation. It is composed of antibodies and used to treat certain venomous bites and stings. Antivenoms are recommended only if t ...

that provides protection against bites from this species.

Diet

''C. defilippii''

preys Predation is a biological interaction where one organism, the predator, kills and eats another organism, its prey. It is one of a family of common feeding behaviours that includes parasitism and micropredation (which usually do not kill th ...

predominately upon small amphibians. 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. . (''Causus defilippii'', pp. 113–114 + Plate 15).

Reproduction

''C. defilippii'' 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), a ...

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 six to eight eggs, each of which measures 23 x 15 mm (.91 x .59 inches). Each hatchling has a total length (including tail) of around .