Subterranean Fishes of the World

The specific name was originally spelt spelaeus but was corrected to spelaea by Woods and Inger (1957)

The common name is Northern Cavefish (Page et al. 2013, Adams et al. 2020)

Country

Types

Holotype: an individual approximately  85mm long. The location of this specimen (originally in the “Cabinet of the Lyceum”) is unknown and no other types were assigned. The most important definition of this species is given by Woods and Inger (1957:244 245). This is the type species by monotypy of the cave restricted genus Amblyopsis.

Distribution

Kentucky, USA.

Type locality: Mammoth Cave, Kentucky, USA (37^o10’N, 85^o55’W). Found in caves and springs on the Crawford and Mammoth Cave uplands and the Mitchell Plain, southward of the Ohio River (Chakrabarty et al. 2014). Originally thought to be also distributed north of the Ohio River in Indiana this is not now the case and the Indiana cave fishes are a separate species, Amblyopsis hoosieri (Chakrabarty et al. 2014). A survey of the species in Kentucky was conducted by Keith (1988) and he found 17 sites in Kentucky with this species. In Mammoth Cave this species coexists with Typhlichthys subterraneus. [Romero and Bennis (1998) record this species from “about 2500 caves in Kentucky". This figure is clearly in error].

Habitat

Inhabits cool (8-17^oC) hypogean streams which have mixed mud/rock substrates in shoals, and mixed sand/silt substrates in pools (Burr and Warren, 1986:219). The preferred habitat of this species in Mammoth Cave is in deep base level rivers fed by Sinkhole Plain drainage and with a low food supply (Poulson 1961, 1963 and pers. comm.). Barr and Kuehne (1971) provide details of the habitat within Mammoth Cave. Compson (2004) used an isotopic study to show that T. subterraneaus, and probably also Amblyopsis spelaea, is a top predator within the cave ecosystem (see also Helf and Olson 2017).

Systematics

There are nine known and named taxa in the Family Amblyopsidae. Of these six are subterranean fishes with the usual troglomorphic characters of reduced eyes and pigment and permanent subterranean existence, and three are epigean fishes with normal eyes and pigment. Recent molecular and morphological evidence produced by Hart et al. (2020) demonstrates that the relationship between these hypogean and epigean fishes is not simple. There are four major clades within the Family:

1. Typhlichthys subterraneus and Typhlichthys eigenmanni are sister species and sister to this pair is Speoplatyrhinus poulsoni.  However, T. subterraneus is quite clearly divided into two subgroups, one of which is closer to T. eigenmanni than it is to the other group of T. subterraneus. The only way to read the cladogram for this group is that it consists of three taxa, one of which is currently un-named. This clade are all subterranean fishes.

2. Two of the epigean fishes, Forbesichthys papilliferus and Forbesichthys agassizii, are sister to each other and their sister is the hypogean species Amblyopsis spelaea.

The two remaining clades contain one species each but their relationships to the other six species is ambiguous:

3a. Sister to the above groups is epigean Chologaster cornuta with hypogean Troglichthys rosae sister to all other taxa.

3b. Sister to the above groups is hypogean Troglichthys rosae with epigean Chologaster cornuta sister to all other taxa.

Given the fact that the distribution of Chologaster cornuta is very far from the distributions of the other taxa 3b seems the most parsimonious explanation. Amblyopsis hoosieri is not included in the paper of Hart et al. (in press) but one would expect it to be in group 2 above based on geography.

This analysis does not take into account the ten possible cryptic taxa, currently subsumed within Typhlichthys subterraneus, identified by Graening, Fenolio and Slay (2011), Niemiller et al. (2013) and Hart, Burress and Armbruster (2016).

Museum Holdings

CM, FMNH, IU, UMMZ, NPS (Woods and Inger 1957:244); BMNH, plus many other museums in the USA.