The hermaphroditic anglerfish

Alexander Ogurtsov | Dreamstime.comanglerfish

Sexual fusion and the Fall

by Bruce Lawrence

The anglerfish is a strange creature that comes in many varieties. However, there are some anglerfish that pose an interesting question from a biblical worldview.

Male and female

Fish are nephesh chayyah, and as such these specific varieties of anglerfish cannot be addressed in the same way that we address the death of insects and plants in relation to the Fall. Unlike insects or plants, fish are not biological robots. The examples of concern are some species of ceratioid anglerfish. Ceratioid anglerfish express extreme sexual dimorphism. Sexual dimorphism means there are physical differences between males and females that go beyond just their reproductive organs. Animals that exhibit extreme sexual dimorphism are often drastically different in size and appearance. Some of them are so different that you would never know they were the same species just by looking at them.


Anglerfish are bony fish belonging to the order Lophiiformes. Most people think of the anglerfish as a ghastly creature that has numerous long, pointy teeth, cold eyes, and a light that is released by the lure that hangs on its head. This light is used to attract unsuspecting prey (the glow itself is produced by bioluminescent bacteria that live in the flesh bulb). While there are many varieties of anglerfish that drastically differ in appearance and environment, they all have a lure of some kind that they use to attract prey.

Anglerfish in the suborder Ceratioidei live in the ocean depths, under enormous pressure and little or no light. Male ceratioid anglerfish are much smaller than the females, lack the glowing bulb they are named after and have much smaller teeth. Their appearance is like a tiny guppy. The males swim around in darkness and use their highly developed sense of smell or sight (depending on the species) to track down females in the complete darkness of their deep-sea environment.

Once the male finds a female, he quickly latches onto her with his teeth to start a process that sounds like the stuff of science fiction. The male begins to fuse his body to the female, and his body enlarges like a deformed tumour. As it grows, it begins to lose limbs and organs. Its fins fall off, its eyes cease to function, and it ceases to have its own circulatory system. The blood that carries oxygen through its body comes from the female.

Now the creature exists as nothing but a sperm bank for the female. At this point, the male seems to be just an extension of the female’s body. The males have little decision in this matter, as they can only live for a few months without attaching to a female. The males are too weak and underdeveloped to feed themselves after birth. So, from the moment they are born, they seek out a mate; failure brings death by starvation or predation. There are about 25 species of ceratioid anglerfish that have some variation of this unique mating process.1

This is a rather dark mating process, that can cause some people to question the goodness of a God who would force creatures to endure such a harsh life.

Anglerfish in a biblical Creation/Fall world

We must remember that God created the world very good, and without death (of nephesh chayyah). Adam corrupted the world when he betrayed God, and through sin, death entered the world. After the Fall, animals began to behave violently, engaging in carnivory, cannibalism, and general violence. Mutations (copying errors in DNA) began to accumulate, and these defects altered the way animals lived.

With this in mind, let’s re-examine the anglerfish. Many varieties of anglerfish do not reproduce in this manner. Instead, after latching onto the female with their teeth; they release their sperm (fertilizing the eggs), detach, and swim away.2 This shows that the practice of fusing with the female is not universal and only exists among some members of the ceratoid anglerfish3.

Many anglerfish varieties do not express this extreme sexual dimorphism, and their appearance fits their name. Some researchers have argued that in some species, whether the males fuse to a female’s body is dependent on how sexually mature the female is. If she is fully matured, then the immune system is also properly developed, and the fusion doesn’t occur.4

All of this paints a pre-Fall picture, the anglerfish kind originally reproduced then detached. But after the Fall, some descendants of the original anglerfish suffered from degenerative mutations that caused their bodies to begin fusing while mating. While studies on living anglerfish are limited (as it is very difficult to keep them alive in artificial environments) scientists have postulated specific mutations that would make this process very simple.

Post-Fall mutations

The researchers propose that a series of mutations disabled the immune system. Antibodies no longer mature and create receptors for T-cells. As a result of this, when the male bites onto the female, he releases digestive enzymes that break down the tissue of both the male’s mouth and the female’s skin. The damaged tissues begin to repair themselves; but the bodies of the male and female do not recognize that they are separate, and this healing process fuses them.

“Their bodies fuse: vessels join like the colliding roots of trees, and tissues form one shared body. The male is a mere appendage, hanging onto the female like a vestigial limb. What he does not need, he no longer has; eyes and fins disintegrate in atrophy and her blood supply is now his (Duarte et al, 2001). He is merely a sperm bank.”3 

This genetic deterioration or “de-volution” provided survival advantages in the harsh deep-sea environment, but it created a miserable life for the crippled males.

 This aids survival because these specific varieties of anglerfish live in a large, dark environment. In this home the anglerfish are isolated, and rarely see other members of the species. This makes it hard for a male and female to find each other when they are ready to spawn. If the male has fused to the female, he is there and ready to breed with her whenever she is ready to spawn. This makes reproduction easier to accomplish in this environment.

Many have described this as evolution removing key functions of the organism’s immune system, but to call this ‘evolution’ is misleading. Evolution on a grand scale requires the development of new features and structures. For evolution to be valid, it must create the immune system, not erase key parts of it in a way that happens to be useful. Adaptation through loss of function is the opposite of ‘microbes to man’ evolution. These kinds of genetic changes could never produce the numerous kinds of lifeforms across the earth, even if we grant billions of years for the mutations to occur, accumulate, and be fixed into the populations. So, it is unreasonable to act as if this is evidence of evolution and this adaptation is readily explained from a Biblical perspective.

It won’t stay this way

While nature is “red in tooth and claw” this is not a result of unguided evolution operating over millions of years, or the design of a cruel God who created things with the intent that they would suffer and die. These things are the product of human sin, severing our relationship with God. The horrible things seen in nature, occur because we live in a sin-cursed world that is subject to decay. However, there is hope. God has not abandoned his creation to wither away without him, but has offered us salvation, and has promised to create a new world that is free from the scars of sin.

“For as by a man came death, by a man, has come also the resurrection of the dead. For as in Adam all die, so also in Christ shall all be made alive. … The last enemy to be destroyed is death” (1 Corinthians 15:21–22, 26).

Published: 24 November 2022

References and notes

  1. Winter, C., Angler Fish Reproduction: When Two Become One, Imperialbiosciencereview, 11 2020. Return to text.
  2. Deep-Sea Anglerfish, oceana.org. Return to text.
  3. Castro, J., Animal Sex: How Anglerfish Do It, livescience.com, 6 Jan 2015. Return to text.
  4. Pietsch, T. Dimorphism, parasitism, and sex revisited: modes of reproduction among deep-sea ceratioid anglerfishes (Teleostei: Lophiiformes), Ichthyol Res 52:207–236, 2005 |doi:10.1007/s10228-005-0286-2. Return to text.

Helpful Resources

A Question of Origins
by Shelby MacFarlane
US $9.00
epub (ebook) download
Wonders of Creation: Design in a Fallen World
by Stuart Burgess, Andy McIntosh and Brian Edwards (editor)
US $35.00
Hard cover