Subterranean Fishes of the World

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

Country

Types

Description based on a syntype series of three individuals: USNM 8563. This species is the type species by monotypy of the cave restricted genus Typhlichthys.

Distribution

Alabama, Georgi, Kentucky, Tennessee, posssibly Arkansas, USA

Type locality: a well near Bowling Green, Kentucky, USA (37^o00’N, 86^o30’W), the exact location of the well is not known. The range is discontinuous, with a western component including central and southern Missouri, and northern Arkansas, and an eastern component which extends from the south‑central tip of Indiana, southwards through Kentucky, into central Tennessee, northern Alabama and the north west tip of Georgia (35-40^oN, 85-95^oW). The Mississippi River runs between these two areas and other major rivers divide the range. Although once thought to be resident in Oklahoma this species is in fact absent from this state. Mayden and Cross (1983) have shown that all records of T. subterraneus from Oklahoma are in fact of Troglichthys rosae. Records from Greene County, Missouri have been shown by Jones and Taber (1985) to be in error and therefore the indication in Woods and Inger (1957:245) that T. subterraneus and T. rosae are sympatric no longer holds. These two species do not overlap in distribution. In Mammoth cave, Kentucky, but nowhere else, this species coexists with A. spelaea and Woods and Inger (1957) have suggested that this is because of competitive exclusion. This range lies within an area bounded by the southernmost limit of glaciation and the northernmost limit of the Cretaceous Mississippi embayment. In Mammoth Cave, Kentucky this species coexists with Amblyopsis spelaea and in Key Cave, Alabama with Speoplatyrhinus poulsoni.

Niemiller et al. (2016) report a significant range extension for the species to Catoosa Co. Georgia.

Habitat

Inhabits cool (10‑14^oC) lentic waters over substata of mixed gravel, sand, and mud (Burr and Warren 1986:221). The preferred habitat of this species is in shallow streams fed by vertical shaft drains and with a moderate food supply (Poulson 1961, 1963 and pers. comm.). Schubert (1993), Schubert, Nielsen and Noltie (1993) and Schubert and Noltie (1995) made an experimental study of the substrate preference of this species. In all tests it significantly preferred cobbles to any other substrate. Cobbles have interstices large enough for the fishes to hide in and they spent much time there. Schubert and Noltie (1996) studied feeding. 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). This species was known from Hidden River Cave but was extirpated from it, along with all other naturally occuring fauna, by intense pollution by sewage. After this problem was dealt with the natural fauna slowly recolonised the cave and T. subterraneus reappeared in 1993 and was still present in 2014 (Lewis et al. 1982, Lewis 1995, Jones and Pearson 1997, Lewis et al. 2015, Helf and Olson 2017 section 14.4.1, Table 14.3).

Systematics

Until the revision of Woods and Inger (1957) there were three nominal species of Typhlichthys, a fourth nominal species was based on a nomen nudum and was therefore invalid (Poly and Proudlove 2004). The population from Sloans Valley Cave, Pulaski County, Kentucky differs in a number of ways from other populations and may represent an undescribed taxon (Cooper and Beiter 1972, Burr and Warren 1986:221). No further details of this population have been published. Genetically, however, the populations are very distinct, even those that are close geographically (Swofford, Branson, and Sievert 1980). This genetic information supports the hypothesis of Cooper and Iles (1971) that morphological similarity may be more a matter of similar selective regimes resulting in parallel evolution than any significant gene flow which is difficult to support because of the major river divides to the range. Barr and Holsinger (1985) support this idea and suggest that the “species” is a composed of several local phylogenetic species separated by extrinsic dispersal barriers (i.e. rivers and non‑karstic geology). Swofford, Branson and Sievert (1980) however suggest that morphological and genetic divergence have been uncoupled.  See below for more recent data.

Rosen (1962) has suggested that all Amblyopsid fishes be placed in a separate order, the Amblyopsiformes. This suggestion has not been followed by subsequent authors (e.g. Greenwood, Rosen, Weitzman and Myers 1966, Nelson, Grande and Wison 2016).

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

KU 12853, SIUC 4129, 4130, 4131 (Mayden and Cross 1983); UMMZ 136379 (4 specimens) (Jones and Taber 1985); UAIC 656, AU 2067 (Cooper and Iles1971); UMMZ 133844 (formerly catalogued asTroglichthys rosae), ASUMZ 9064 (Paige, Tumlinson, and Mc Daniel 1981); also specimens at USNM, CAS‑SU, FMHM, MU, KU (Woods and Inger 1957); BMNH. KU:KUIT:8754, UAIC 14148.01 (Malmstrom et al. 2017, used for genome sequencing).

Probably many other specimens in museums in the USA.

ANSP, AUM, CAS, CMN, FMNH, KU, MCZ, MOSU, SIUC, TU, UAIC, UF, UL, UMMZ, USNM, UTIC, YPM (Niemiller et al. 2013)