''Varanus spinulosus'', the Solomon Island spiny monitor, Isabel monitor,
[ or spiny-neck monitor, 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 ...
of monitor lizard. It 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 else ...
to the Solomon Islands archipelago
The Solomon Islands (archipelago) is an island group in the western South Pacific Ocean, north-east of Australia. The archipelago is in the Melanesian subregion and bioregion of Oceania and forms the eastern boundary of the Solomon Sea. The ...
and is also known from Santa Isabel Island
Santa Isabel Island (also known as Isabel, Ysabel and Mahaga) is the longest in Solomon Islands, the third largest in terms of surface area, and the largest in the group of islands in Isabel Province.
Location and geographic data
Choiseul lies t ...
, San Jorge Island (Solomon Islands
Solomon Islands is an island country consisting of six major islands and over 900 smaller islands in Oceania, to the east of Papua New Guinea and north-west of Vanuatu. It has a land area of , and a population of approx. 700,000. Its capit ...
) and Bourgainville Island (Papua New Guinea
Papua New Guinea (abbreviated PNG; , ; tpi, Papua Niugini; ho, Papua Niu Gini), officially the Independent State of Papua New Guinea ( tpi, Independen Stet bilong Papua Niugini; ho, Independen Stet bilong Papua Niu Gini), is a country i ...
).[
]
Taxonomy
''Varanus spinulosus'' was first described by Robert Mertens in 1941 from a singe male specimen, and named ''Varanus indicus spinulosus'' as a subspecies of the mangrove monitor
The mangrove monitor, mangrove goanna, or Western Pacific monitor lizard (''Varanus indicus'') is a member of the monitor lizard family with a large distribution from northern Australia and New Guinea to the Moluccas and Solomon Islands. It grows ...
. This species was known only by the holotype until 1989, when 5 female specimens were collected. In 1994, the taxon was elevated to specific status as ''Varanus spinulosus'', but remained a member of the subgenus ''Euprepriosaurus'' and the ''V. indicus'' species complex until it was declared ''incertae sedis
' () or ''problematica'' is a term used for a taxonomic group where its broader relationships are unknown or undefined. Alternatively, such groups are frequently referred to as "enigmatic taxa". In the system of open nomenclature, uncertain ...
'' in 2010, when it was concluded that the species likely represented a new subgenus due to its genital morphology. In 2016, the monotypic subgenus ''Solomonsaurus'' was coined for this species based on its unique scale structure, the latter which is reflected by this taxon's specific epithet ''spinulosus'', meaning "spiny".
Description
This species is in many respects similar to the mangrove monitors of the ''V. indicus'' species complex, but has a number of unique morphological characteristics. It has a spiny scale texture as each of the small body scales are strongly keeled and conical in shape, which is a feature unique amongst all monitor lizards. It has 3-4 rows of bright yellow spots running across its back, and has relatively large eyes.
Diet
They feed on megapode eggs and on fish, often emerging from the bush. In the intertidal zone at low tide, it is possible that they would search for dead fish.
Relationship with humans
During the 1990s, many ''V. spinulosus'' were imported under the common name “mangrove monitor” due to increased desirability in the pet trade.
References
{{Taxonbar, from=Q3014194
Varanus
Reptiles of Papua New Guinea
Reptiles of the Solomon Islands
Reptiles described in 1941
Taxa named by Robert Mertens