Creatures in Crisis
Photograph of Sulphur molly (Poecilia sulphuraria), recorded as Endangered
Sulphur molly (Poecilia sulphuraria). Image via Wikimedia Commons.

Endangered

Sulphur molly

Poecilia sulphuraria

Sulphur molly is a livebearer in the family Poeciliidae (order Cyprinodontiformes) — Poecilia sulphuraria, recorded as Endangered.

Status
Endangered
Scientific name
Poecilia sulphuraria
Taxonomy
Cyprinodontiformes · Poeciliidae · Poecilia

Appearance

The head is broad, and the snout-to-dorsal-fin distance is long, giving the fish a somewhat front-heavy appearance. The caudal fin is truncate, rather than rounded or forked. The dorsal fin is short and set far back on the body, especially in females.

The maximum recorded standard length is 50 mm.

Range and habitat

The type locality is Baños del Azufre and their outlet stream, Arroyo Azufre, within the Grijalva River basin, about 12 km west of Teapa, on the border between the Mexican states of Chiapas and Tabasco. Aquatic vegetation is almost entirely lacking. Small patches of green algae occur sporadically. Hydrogen sulfide (H₂S), that is abundant in the sulfur molly's habitat, is a potent respiratory toxin. The few animals that tolerate it tend to be invertebrates.

Pins are Wikidata “endemic to” fields. Orange dots, when present, are GBIF occurrence tiles — survey bias included.

Breeding

Livebearers drop free-swimming young. Many species occupy springs, lakes, or ditches with little room to retreat.

Small desert or forest fishes in this order live in water that can vanish. The egg bank, if there is one, is the only reserve.

In crisis

The high concentration of hydrogen sulfide in the water forces the fish to spend most of their time breathing on the surface, that exposes them to predatory birds. The species has evolved a wave-making behavior to avoid predation.

Sulphur molly is Endangered on this catalog because that is the IUCN category stored on Wikidata. Confirm the official criteria and any later count on iucnredlist.org.

Sources

Written for this catalog from the English Wikipedia article on Sulphur molly, Wikidata item Q557723. Family and order context is original field-guide writing about the group, not a copied assessment of this one species. Wikipedia text is CC BY-SA. Not an IUCN assessment. Counts, when quoted, can change — confirm them on the recovery programme and on iucnredlist.org.

Photograph via Wikimedia Commons. Wikipedia · Wikidata · IUCN Red List.

Also in this catalog

Photograph of Vaquita (Phocoena sinus), recorded as Critically EndangeredCR

Vaquita

Phocoena sinus
Photograph of Javan rhinoceros (Rhinoceros sondaicus), recorded as Critically EndangeredCR

Javan rhinoceros

Rhinoceros sondaicus
Photograph of Sumatran orangutan (Pongo abelii), recorded as Critically EndangeredCR

Sumatran orangutan

Pongo abelii
Photograph of Axolotl (Ambystoma mexicanum), recorded as Critically EndangeredCR

Axolotl

Ambystoma mexicanum

Quick answers

What is Sulphur molly?
Sulphur molly is a livebearer in the family Poeciliidae (order Cyprinodontiformes) — Poecilia sulphuraria.
What is the conservation status of Sulphur molly?
Endangered, as the IUCN category stored on Wikidata for Poecilia sulphuraria. Confirm the official assessment on iucnredlist.org.
Where does Sulphur molly live?
The sulfur molly is one of few fish that permanently inhabit sulfidic habitats, and tolerates higher concentrations of hydrogen sulfide than the other species endemic to Baños de Azufre, Gambusia eurystoma.
Why is Sulphur molly in crisis?
The high concentration of hydrogen sulfide in the water forces the fish to spend most of their time breathing on the surface, that exposes them to predatory birds. The species has evolved a wave-making behavior to avoid predation.
Is this the IUCN Red List page for Poecilia sulphuraria?
No. This is a researched catalog account. The Red List is the assessment.
Is Sulphur molly a pet?
An animal on this catalog is in crisis in the wild. Keeping one is usually the wrong question.