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Mollies

Short-finned Molly ~ Sailfin Molly ~ Mexican Sailfin Molly Family: Poeciliidae

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Silver Lyretail Molly
Gold Molly
Silver Balloon Molly Poecilia sphenops

   The colorful active Molly, Short-finned Molly, Sailfin Molly, or Mexican Sailfin Molly has long held the position of being a most popular fish because it is peaceful, relatively hardy, inexpensive, and readily bred!

   The pictures here show the Short-finned Molly with a gold and silver color and the lyretail and balloon varieties. Mollies come in four main colors; green, black, silver, and gold. There is also commonly available a silver molly with black spots that is call the Dalmation Molly and a Marbled Molly with the same (white and black) colors.

   The Molly, Short-finned Molly, Sailfin Molly, or Mexican Sailfin Molly are strictly American fish, found only on the continents of North and South America. The first Molly was introduced to the hobby 1899 and hybrids began being produced in the 1920's.

   Wild caught mollies fall into two groups. The first group is the common molly with small fins, know as the Short-finned Molly, P. sphenops. The second group is the sailfin molly with large fins which includes two species, the Sailfin Molly, P. latipinna, and the Mexican Sailfin Molly, P. velifera. Other than the fin size, another easy way to distinguish between the two groups is by the location of their dorsal fins. On the sailfin mollies the dorsal fin is situated in front of the anal fin, while on the common molly this fin starts behind the anal fin.

   It is more difficult to distinguish between the two sailfin molly species as their coloring is very similar. Often it can only be determined by the number of rays on the dorsal fin, where the Sailfin Molly, P. latipinna has about 14 rays and the Mexican Sailfin Molly, P. velifera will have nearer to 18 rays.

Mollies got their name from the fact that they used to be in the genus Mollienesia.

   For beginners the Short-finned Molly is the best choice as it is the most durable, least demanding, and needs the least space. The next best choice is a cross breed of Short-finned and Sailfin. The Sailfin Mollies, though often more peaceful, are a bit more challenging to keep. In general all mollies are peaceful, though it has been noted that behavior is very individual, and occasionally you will get a fish that can be quite ornery.

   All Mollies need an aquarium that is well planted and not overcrowded. It is suggested that you add a little salt and that you provide lots of algae and other vegetable foods. The use of breeder traps is hazardous to these fish, and it is recommended that you provide floating plant cover for the fry instead.

For more Information on keeping this fish see:
Guide to a Happy, Healthy Freshwater Aquarium

   Mollies are often found in saline waters and it is recommended that 1 to 1.25 teaspoons of non-iodized salt be added to the aquarium water. The common molly is a bit hardier and can be kept in a smaller aquarium, whereas the sailfin mollies are more delicate and need a larger aquarium with plenty of room. The sailfin mollies also do better when kept with other livebearers that can handle a saline environment. Mollies are prone to ich, fungus and other diseases if their environment is not comfortable for them.

   Provide plenty of plants and floating plant cover for munching on, and for hiding places for the fry.

Distribution:
   Mollies mostly inhabit coastal waters from southeastern North America south to Venezuala, but they have been found in the ocean as well as in brackish and fresh water.
   The Short-finned Mollies, P. sphenops are found from Mexico to the northern part of South America.
   The Sailfin Mollies, P. latipinna, are found along the southeast coast of the United States and the Gulf of Mexico. These are the most common large fin molly as they are easily obtained, inexpensive, and prolific breeders.
   The Mexican Sailfin Mollies, P. velifera come the coastal area of Yucatan, Mexico. This Sailfin is more rare in the hobby because it is not as easily obtained as the P. Latipinna. It is also more difficult to breed and the tank bred often do not have the impressive dorsal and tail finnage. Better success is obtained in ponds.

Most mollies available today are selectively bred or are hybrids:
   Most often the large-fin types are cross breeds of the Short-finned Molly, P. sphenops and the Sailfin Molly, P. latipinna. These cross breeds include the lyretail, moonfish, and flag. It is from the "sailfin" species that albino coloring is obtained.
   The popular "Black Molly", a selectively bred Short-finned Molly, P. sphenops, appeared in 1909 in Europe but was first developed in the United States in the 1930's. These selectively bred fish are not as hardy as original fish, being more susceptible to disease and needing warmer water. Though it was first a small finned molly, it was later crossbred to produce a large finned molly in about 1976.
   The "Midnight Molly" is a selectively bred all black variety of the Sailfin Molly, P. latipinna.
   The Lyretail Molly has all normal fins except for the tail, which is long with the outside edges being longer still. The tail tends to loose its lyre shape as the fish get older. There is also a Veiltail Molly which has a long tail and dorsal fin. Sometimes the fins on this fish are so long that they have trouble swimming. Both the Lyretail Molly and the Veiltail Molly are more difficult to breed due to a very long gonopodium.

Size - Weight - Wild Coloration:
   Short-finned Molly, P. sphenops grows between 2.38 - 4 inches (6 - 10 cm) in the aquarium, and up to 8 inches (20 cm) in nature. Their prominent natural color being a blue body often with yellow or red fins.
   Sailfin Molly, P. latipinna grows between 4 - 6 inches (6 - 10 cm) in the aquarium, and up to 8 inches (20 cm) in nature. Their prominent natural color is a green body often with black dots and a large dorsal fin on the male.
   Mexican Sailfin Molly, P. velifera grows between 4 - 6 inches (6 - 10 cm) in the aquarium, and up to 8 inches (20 cm) in nature. Their prominent natural color is usually a green body often with dark dots and a large sail-like dorsal fin on the male, there is also often an albino strain.

Social Behaviors:
   They are a good community fish.

Sexual Differences:
   The male is slender and has a gonopodium, the female is larger with a fuller body.

Water Region: Top, Middle, Bottom:
   These fish will swim in all areas of the aquarium.

Acceptable Water Conditions:
   Short-finned Molly, P. sphenops and Sailfin Molly, P. latipinna:
     Hardness: 20-30° dGH (absolute lowest is 11°)
     Ph: 6.5 to 8
     Temp: 75-82° F (24-28° C)
   Mexican Sailfin Molly, P. velifera:
     Hardness: 25-35° dGH (absolute lowest is 11°)
     Ph: 7.5 to 8.2
     Temp: 72-82° F (25-28° C)

Breeding/Reproduction:
   These fish will readily breed. See the description of how to breed these fish in Breeding Freshwater Fish, Livebearers.

Availability:
   The selectively bred varieties and cross breeds of the Short-finned Molly, P. sphenops and the Sailfin Molly, P. latipinna are readily available.

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Latest Comments
I have 2 Sunbrst Lyretail Mollies with a dragonfish, a Pleco(stomus), a pictus catfish, and a skirt fish! they are all getting along and are very cool! Bret 2009-08-22
I got red and black mollies which breed every 2 weeks. At one point I had 40 or more fry in my tank which totally amazed me and my girls. Lovely fish. Regards, Mossy mossy 2009-03-15
I have 2 dalmation mollies. From what I can tell, one female and one male. I got a silver molly, but the female dalmation chased it, and killed it. Both when I got them were a silver/tan with black spots. Now the male has turned almost fully black with some blue, green, gold scales, and his tail has turned from white to a dark orange, almost amber. The female looks like she is getting a little big, I was wondering how long a gestation period for the females takes. bill 2009-02-22
I have a short finned yellow molly. It is very small but lonely, and has no partners except two gold fish, which I have. abhilash 2009-02-14
I have 4 Mollies, 1 male and 3 female. I feel so sorry for the male because he has wanted to spawn for awhile now and the females aren't interested. He just looks so sad! Nicky 2008-12-18
Some of the coolest comments:
The Sailfin Mollie is best if not bred for colors other than their natural colors. When in tanks with other fish and are also very peaceable fishes. Like most mollies the Sailfin Mollie reproduces fast in larger habitats most commonly. I know this from observation of this animal in both wild and domesticated states. For more suitable habitats the Sailfin Mollies (and mosquito fish)are best kept in water with a low saline or brackish water level and a ph of 6.8-8.6 with vegitation that trives in an abundant supply. Samuel Brown 2004-05-14
I love mollies! If a fish can be lively and friendly... they are lively and friendly! They follow your finger on the glass and they are always doing something silly. We have 3 females and one male. The male is a dalmation sailfin molly, and 2 of the females are silver lyretails, and the last female is also silver, but shes a sailfin too. I havent seen any fry yet...maybe because I have danios and tetras, but Im going to look next time so I can net them! I recommend them to anyone! Sarah 2004-03-13
Comments Dr Jungle REALLY Likes to Hear!
To whom it may concern, Thank you for sharing your knowledge and expertise on mollies. I have learned much valuable information from your website. I have some mollies coexisting happily with other community fish including guppies, dwarf and Mickey Mouse platys, female bettas, one dwarf frog, and one double tail male betta. They all seem to be doing fine together. I have dalmation, orange and black regular tailed mollies. Recently I purchased some lyre tail mollies. They sure are an active fish. They constantly are speedy swimmers and aggressive breeders. I now have some babies from these fish and they are so cute! I have a silver male lyre tail molly that is often chasing the female fish. He is the stud of my tank so I call him Fabio. He is sometimes chasing the other males and I assume this is his way to get them away from his girl mollies. Luckily I have more females then males so no single female molly is singled out as that would lead to unnecessary stress. For later reference, I have organized your website and other related websites that I may need later. Sincerely, Irene Steffen Irene 2009-07-02
I think that mollies, platys and swordtails have very low defenses against mainly fungus and fungul parasetic diseases and proper precautions should be taken to prevent these diseases. This site gives valuable info. to novices in the fish hobby Strasser Sankar strasser sankar 2004-02-23

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Author: David Brough, CFS & Clarice Brough, CFS.