Empetrichthys merriami

Goodeid
Goodeid
Original Description: 

  GILBERT, C. H. (1893): Report on the fishes of the Death Valley expedition collected in southern California and Nevada in 1891, with descriptions of new species. North American Fauna Nr. 7, part II, Washington: pp 229 - 384

Etymology: 

  This species is named in honour of one of the collectors, C. H. Merriam.

Holotype: 

  Collection-number: United States National Museum, Cat. No. USNM-131151.

  The Holotype is an adult female of 67mm SL. Numbers of Paratypes are: SU 766 (2), USNM 46101 - 03 (3,2,1). The types ("several specimens") have been sampled by C. H. Merriam and V. Bailey in 05. 1891.

English Name: 
Ash Meadows Poolfish (formerly known as Ash Meadows Killifish)
Synonyms: 

Empetrichthys latos   Gilbert, 1893 (one specimen of the types of merriami referred to E. latos, but has not been recognized by Gilbert)

Karyotype: 

 The Karyotype describes the number and appearance of chromosomes during the phase of condensation, classified by the position of the centromere (Levan et al., 1964).

The following abbreviations are employed:

 

M = large metacentric chromsome (a result of Robertsonian fusion)

m = small metacentric chromsome (centromere at medium position)

sm = submetacentric chromsome (centromere at submedian position)

smst = submetacentric-subtelocentric chromosome (continous series)

st = subtelocentric chromosome (centromere at subterminal region)

stt = subtelocentric-acrocentric chromosome (continous series)

t = acrocentric chromosome (centromere at terminal region)

 

The Karyotype of Empetrichthys merriami has not been ascertained.

Size: 
The maximum known SL is 59mm.
Terra typica: 

The Holotype comes from Kings Spring, Ash Meadows, Amargosa Desert, on the boundary between California and Nevada, Nye County, Nevada, USA.

Status after IUCN: 

extinct

Distribution and ESU's: 

This species was endemic to springs in Ash Meadows, Nye County, Nevada, USA. At this location, over a length of 12 miles many springs are spread out on the valley ground. Empetrichthys merriami cannot be found there anymore and is likely extinct.

Habitat: 

Ash Meadows encompasses a number of springfed ponds and wetlands at the edge of the Mojave desert. The springs's temperatures range from 21 to 33°C, though annual fluctuations of temperature are only 2- 7°C within each spring. The submerge vegetation consists of stoneworts of the genus Chara and filamentous algae. Most of the pools are lined with emergent cattails (Typha spp.)

  Empetrichthys merriami preffered deeper pools (~ 2m) and was rarely seen in shallower areas.

Colouration: 

There is no description of the colouration of live animals known. Gilbert wrote 1893: "In spirits the color is dark brown above, sides and below lighter, often irregularly blotched with brown and white. The belly often appears checkered, having centers of scales brown and margins white, or the reverse. Fins all dusky, the basal portions of dorsal and caudal with elongated brown spots on the interradial membranes."

Biology: 

There is nothing known about the biology of this extinct species.

Diet: 

Regarding the habitat and the feeding habits of related inhabitants of thermal springs, Empetrichthys merriami probably had been an opportunistic omnivore, feeding on algae and invertebrates. Taking in consideration a relatively short intestine ( about 1 1/2 times of TL), the biserial conical teeth with the outer series enlarged, this species seems to had been rather carnivorous.

Remarks: 

C. H. Merriam and V. Bailey collected this species - at least they thought to have collected only one species - in several specimens in the Ash Meadows spring and one specimen in the Pahrump Valley. This one fish from Pahrump belonged to another species, the later described Empetrichthys latos.

   R. R. Miller reported in 1948, when he described Empetrichthys latos, about the rareness of Empetrichthys merriami. During a 6-year period of sampling fish in the Amargosa River drainage, he had been able to collect only as few as 22 specimens out of 5 springs. Myers and Wales sampled 3 in 1930. This species was last seen in 1948 and is believed to have gone extinct in the early 1950s, likely as a result of habitat alteration, and competition with and predation by, introduced nonnative crayfish (Procambarus clarkii), mosquitofish (Gambusia affinis), Black mollies (Poecilia sphenops), and bullfrogs (Rana catesbiana).

   Species of the subfamily Empetrichthyinae are oviparous fishes. PARENTI (1981) proposed this subfamily as sister group to the Goodeinae and used the family name Goodeidae to encompass the two subfamilies. This narrow relationship has been supported by several studies since the 1980's (WEBB, DOMINGUEZ).  

   Both genera of this subfamily share the lack of pelvic fins.

   In 1984, much too late for Empetrichthys merriami, the Ash Meadows National Wildlife Refuge was established to protect the endangered plant and animal species of this area. Four species of plants and animals are endemic, including the endangered pupfishes Cyprinodon diabolis, Cyprinodon nevadensis mionectes, Cyprinodon nevadensis pectoralis and the Ash Meadows Speckled Dace, Rhinichthys osculus nevadensis.

First Describer: 
Gilbert, 1893
Photos: 

Image 1: Empetrichthys merriami, immature male

Drawing: Grace Eager

Image 2: Empetrichthys merriami, adult male

Photographer: F. W. Ouradnik