“Mola” most commonly refers to the ocean sunfish (Mola mola), one of the heaviest bony fish in the world, capable of weighing over 2,300 kilograms (about 5,000 pounds). But the word has two other important meanings: in medicine, a mola (or molar pregnancy) is an abnormal growth that forms in the uterus instead of a healthy pregnancy, and in textile art, a mola is a vibrant hand-sewn fabric panel made by the Guna people of Panama and Colombia. This article covers all three.
The Ocean Sunfish: One of the Strangest Fish Alive
The ocean sunfish, or Mola mola, looks like a massive floating head. Its body is tall and flat, often taller than it is long, with no real tail fin. Instead, it has a stiff, rudder-like structure called a clavus where a tail would normally be. A tall dorsal fin on top and an anal fin on the bottom give it its signature disc-shaped silhouette. Adults can reach 3.3 meters (nearly 11 feet) in length and tip the scales at up to 5,100 pounds. From dorsal fin tip to anal fin tip, the largest individuals span 4.3 meters. Despite their enormous size, ocean sunfish have surprisingly small mouths with fused, beak-like teeth.
The Mola mola belongs to a family called Molidae, which currently includes five recognized species across three genera. The name “mola” comes from Latin, meaning millstone, a reference to the fish’s round, grey, rough-textured body.
Diet: Not Just Jellyfish
For years, ocean sunfish were assumed to eat almost nothing but jellyfish. That reputation turns out to be mostly wrong. A DNA analysis of stomach contents from 57 sunfish identified 41 different prey items. Jellyfish and their relatives accounted for only about 16% of what the fish consumed. The bulk of their diet was crustaceans and small fish.
Their eating habits also shift as they grow. Young sunfish feed broadly on small crustaceans, fish, mussels, and squid in shallow coastal waters. As they get larger, they move to deeper, more open water and start eating more jellyfish-type prey. Subadults over 80 centimeters long had diets where jellyfish-related species made up around 57% of what they consumed. This makes the ocean sunfish a true generalist predator with a more important role in coastal food webs than scientists previously realized.
Parasites and Cleaning Behavior
Ocean sunfish are notorious parasite hosts. Researchers have documented 54 different parasite species living on or in a single Mola mola species. To deal with this burden, sunfish seek out cleaning stations where small fish pick parasites off their skin. They also float on their sides at the ocean surface, a behavior called basking, which may invite seabirds to help. In one remarkable observation in the western North Pacific, a school of 57 sunfish actively followed a resting Laysan albatross and presented themselves to the birds. Four albatrosses then began picking parasitic crustaceans directly off the sunfish’s skin.
Conservation Concerns
Ocean sunfish face growing threats. They are highly vulnerable to mass bycatch in commercial fishing nets, and they are deliberately targeted by unregulated fisheries in Japan, Taiwan, and South Korea. Basic details about their life cycle remain poorly understood, and no conservation or management plans exist across their range. Recent regional declines in abundance prompted the IUCN to revisit its Red List assessments for the entire sunfish family, with two species being evaluated for the first time.
Molar Pregnancy: A Medical Meaning of “Mola”
In medicine, a mola (formally called a hydatidiform mole) is a rare type of abnormal pregnancy in which a mass of tissue grows inside the uterus instead of a normal embryo. It results from abnormal fertilization, where the placental tissue proliferates into a cluster of fluid-filled cysts while the fetus either develops abnormally or doesn’t develop at all.
Complete vs. Partial Molar Pregnancy
There are two types. A complete molar pregnancy produces an abnormal placenta with no fetus whatsoever. It tends to cause very high levels of the pregnancy hormone hCG, often exceeding 100,000 mIU/mL. On ultrasound, a complete mole shows a characteristic “snowstorm” pattern of mixed echoes, or earlier in pregnancy, a fine honeycomb-like appearance.
A partial molar pregnancy involves an abnormal placenta alongside some fetal development, though the fetus is not viable and often shows signs of having three sets of chromosomes instead of the normal two. Hormone levels in a partial mole tend to fall within the normal pregnancy range, making it harder to diagnose. Ultrasound may show only scattered cystic spaces within the placenta.
Why Follow-Up Matters
The main concern after a molar pregnancy is the risk that some of the abnormal tissue persists and becomes cancerous. About 15% of complete molar pregnancies progress to a condition called gestational trophoblastic neoplasia, which can in rare cases develop into choriocarcinoma, an aggressive but highly treatable cancer. The risk after a partial mole is lower, around 5%. Because of this, hormone levels are monitored regularly after treatment to make sure they return to zero and stay there. Most molar pregnancies are caught early by ultrasound, often before 12 weeks of pregnancy.
Guna Molas: A Textile Art Form
In the Guna (also spelled Kuna) language, “mola” literally means “clothing,” “dress,” or “blouse.” It refers to intricately hand-sewn fabric panels created by Guna women of Panama and Colombia using a technique called reverse appliqué. Rather than stitching pieces on top of a base fabric, the artist layers multiple sheets of differently colored cloth, then carefully cuts through the top layers and folds them back to reveal the colors underneath. Each cut edge is stitched down by hand. A single mola can have four or more colored layers, plus additional fabric pieces and embroidery accents. Even a simple design takes many hours to complete.
The tradition likely emerged in the 19th century, when trade with foreign ships brought cotton cloth, needles, thread, and scissors to Guna communities. Before that, Guna women painted elaborate designs directly on their bodies. The shift to textile was also influenced by missionaries who insisted the Guna wear clothing. What could have been a loss of cultural expression became instead a new medium for it.
Today, molas serve a dual purpose. Women wear them as a powerful expression of Guna ethnic identity, depicting everything from social and political commentary to scenes from daily life. Some Guna communities require women to wear molas as a way of upholding tradition and asserting cultural autonomy. At the same time, molas have become an important source of income. Guna women sell them to collectors and tourists, gaining economic status and influence beyond their traditional matrilineal society. The mola has also been adopted as a symbol of Panamanian national identity, worn and displayed well beyond Guna communities.