Family Reference
Livebearers
Poeciliidae — guppies, mollies, platies, and swordtails: matrotrophic fish that breed reliably in any tank that holds water.
The Complete Livebearers Guide: Guppies, Mollies & More
Field reference to livebearing aquarium fishes: Poeciliidae biology, internal fertilisation, hard-water husbandry, hybridisation, disease.
Read the guide →Species & Profiles
All articles in this section
Why Are My Mollies Shimmying?
Molly shimmying is a neuromuscular symptom of osmotic stress — usually soft water. Causes, diagnosis, and step-by-step correction including marine salt use, temperature, and water change protocol.
Why Do My Guppies Keep Dying?
Chronic guppy mortality traces to farm-line inbreeding, mycobacteriosis, and water that is too soft or too cold. How to diagnose the cause in your tank, and what changes actually work.
Endler's Livebearer (Poecilia wingei): Pure vs Hybrid Care
Field profile of Poecilia wingei: identification, hard-water parameters, behaviour, diet, breeding, tankmates, and common aquarium problems.
Black Molly (Poecilia sphenops): Melanistic Molly Care
Field profile of Poecilia sphenops: identification, hard-water parameters, behaviour, diet, breeding, tankmates, and common aquarium problems.
Swordtail (Xiphophorus hellerii): Size, Sexing & Care
Field profile of Xiphophorus hellerii: identification, hard-water parameters, behaviour, diet, breeding, tankmates, and common aquarium problems.
Wrestling Halfbeak (Dermogenys pusilla): Surface Livebearer Care
Field profile of Dermogenys pusilla: identification, hard-water parameters, behaviour, diet, breeding, tankmates, and common aquarium problems.
Four-eyed Fish (Anableps anableps): Brackish Surface Specialist
Field profile of Anableps anableps: identification, hard-water parameters, behaviour, diet, breeding, tankmates, and common aquarium problems.
Dalmatian Molly (Poecilia sphenops): Spotted Molly Care
Field profile of Poecilia sphenops: identification, hard-water parameters, behaviour, diet, breeding, tankmates, and common aquarium problems.
Guppy (Poecilia reticulata): Care, Lines & Disease
Field profile of Poecilia reticulata: identification, hard-water parameters, behaviour, diet, breeding, tankmates, and common aquarium problems.
Common Molly (Poecilia sphenops): Freshwater or Brackish?
Field profile of Poecilia sphenops: identification, hard-water parameters, behaviour, diet, breeding, tankmates, and common aquarium problems.
Platy (Xiphophorus maculatus): Care & Colour Forms
Field profile of Xiphophorus maculatus: identification, hard-water parameters, behaviour, diet, breeding, tankmates, and common aquarium problems.
Limia (Limia spp.): Caribbean Livebearer Care
Field profile of Limia spp.: identification, hard-water parameters, behaviour, diet, breeding, tankmates, and common aquarium problems.
Sailfin Molly (Poecilia latipinna): Brackish-Tolerant Care
Field profile of Poecilia latipinna: identification, hard-water parameters, behaviour, diet, breeding, tankmates, and common aquarium problems.
Least Killifish (Heterandria formosa): Tiny Matrotrophic Livebearer
Field profile of Heterandria formosa: identification, hard-water parameters, behaviour, diet, breeding, tankmates, and common aquarium problems.
Mosquitofish (Gambusia affinis/holbrooki): Care & Cautions
Field profile of Gambusia affinis/holbrooki: identification, hard-water parameters, behaviour, diet, breeding, tankmates, and common aquarium problems.
Variatus Platy (Xiphophorus variatus): Cooler Hard-Water Care
Field profile of Xiphophorus variatus: identification, hard-water parameters, behaviour, diet, breeding, tankmates, and common aquarium problems.
Pike Livebearer (Belonesox belizanus): Predatory Livebearer Care
Field profile of Belonesox belizanus: identification, hard-water parameters, behaviour, diet, breeding, tankmates, and common aquarium problems.
Balloon Molly (Poecilia sphenops): Welfare and Care Limits
Field profile of Poecilia sphenops: identification, hard-water parameters, behaviour, diet, breeding, tankmates, and common aquarium problems.