Silverfish

Lepisma saccharina, the scientific name of Silverfish. These species are characterized by quick-moving, slender, flat, wingless insects. They have three tail bristles and silvery scales spiralling around their body. Silverfish insects are generally considered pests who are thriving indoors. Silverfish Insects are classified along with the firebrat in the order of Zygentoma.   

Here, we will learn in detail about these species called silverfish. We are going to learn about its reproduction and other interesting facts about these pests.

Silverfish – Really a Fish?

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Silverfish as fish is hard to accept. They are moreover insects with their small and wingless body who belong to the order of Zygentoma. This insect has a silvery light grey colour body. It gets its appearance as a fish when it makes movements for this reason this species gets the name - silverfish. Hence, this is the only logic to call the Silverfish fish.

Save Your Book Bindings and Fabrics!

Silverfish are considered to be pests as they eat materials that contain high percentages of starch, like paste, book bindings, and even wallpaper. Silverfish cause literal damage to books and to the fabrics.

Unlike Other Insect Groups – Way of Reproduction

Appearance-wise, the male silverfish resembles the female - both the antennae and the tail bristles are much shorter than the body. Unlike other groups of real insects, the silverfish performs courtship movements that end with the male depositing a sperm pack which the female places in her vagina. The oval whitish eggs are then thought to be inserted into the cracks and in the soil litter. The young ones will hatch in several days. The baby silverfish is scaleless and they have short appendages. They moult after every few days, gradually after which they acquire adult features. The silverfish continues to moult throughout the two or more years or for its entire life, even after reaching their sexual maturity.

Description of the Insect – Silverfish

Length of the Insects

Silverfish are nocturnal insects. They are typical of 13–25 mm (which is 0.5–1.0 in) long. Their abdomen tapers at the end, this gives them a fish-like appearance.

Cute silverfish - Eggs 

While the newly hatched eggs are whitish, they develop a greyish hue and give a metallic shine as they begin to get older. The silverfish has two long cerci, they also have one terminal filament at the tip of their abdomen which is between the cerci. They also have two small compounded eyes. While, other members of Zygentoma are completely eyeless, such as in the family of Nicoletiidae.  

Silverfish “Fish”

The silverfish are wingless and have a long antenna that moves in a wiggling motion, this resembles the movement in a fish. This gets added with its appearance and with its silvery scales, all these descriptions make them known as silverfish. If lost, the silverfish can regenerate terminal filaments and their antennae within two to four weeks. 

A Runner

The silverfish is quite an agile runner which can outrun most of its predators (this includes spiders and centipedes). However, this running is possible only on the horizontal surfaces, they are not fast enough to climb the walls at the same speed. Silverfish also avoids light. 

A Cosmopolitan Insect – Distribution of Silverfish

Silverfish are known as cosmopolitan species. They are found in Africa, America, Eurasia, Australia, and other parts of the Pacific. Silverfish inhabits in moist areas which requires a relative humidity which is between 75% to 95%. In the urban areas, they are to be found in the attics, basements, bathtubs, kitchens, old books, sinks, classrooms, and also in showers. 

Reproduction and Life Cycle of the Silverfish

Before the process of reproduction, the silverfish carried out a ritual that involves three phases that may last over half an hour. 

The Ritual Involving Three Phases

• In the first phase, the male and the female silverfish stand face to face, touching their quivering antennae, and repeatedly backing off and returning to the position. 

• In the second phase, the male runs away from the female, and the female chases him. 

• In the third phase, the male and female stand side by side and fix their head to tail, with the male vibrating his own tail against the female.

Finally, the Laying of Spermatophore

After these three processes, finally, the male lays a spermatophore which is a sperm capsule that is covered in gossamer. The female takes this sperm into her body via her ovipositor to fertilize her own eggs. The female lays groups of 60 eggs (or less) at once, which get deposited in small crevices. The eggs are oval-shaped, they are whitish, which is about 0.8 mm (that are 0.031 in) long, and they take between two weeks and two months to hatch these eggs. A silverfish usually lays 100 eggs (or less) in her entire lifetime. 

Nymph Hatching

When the nymphs hatch, they are usually white in colour, and they look like smaller adults. As they moult the young silverfish develops a greyish appearance and a metallic shine, which eventually becoming adults after three months to three years. Also, to note - Silverfish typically live for up to three years. 

Taxonomy

• Kingdom – Animalia

• Subkingdom – Bilateria

• Infrakingdom – Protostomia

• Superphylum – Ecdysozoa

• Phylum - Arthropoda

Scientific Taxonomy 

• Planet – Earth

• Domain – Eukaryota

• Kingdom – Animalia

• Subkingdom – Eumetazoa

• Infrakingdom – Bilateria

• Superphylum – Ecdysozoa

• Phylum – Arthropods 

• Subphylum – Hexapoda

• Class – Insecta

• Subclass – Aoterygota

• Order – Zygentoma

• Family – lepismatidae

• Genus – Lepisma (Silverfish)

• Species – L. Saccharina

Giant Silverfish

Bugs that look like silverfish

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These are Firebrats, they are the species that are quite similar to a silverfish. Their colour varies from grey to brown, coupled with dark spots on their back, while their body shape resembles that of a carrot. These firebrats are of the same size as giant silverfish, they have small antennae which look quite similar to them. Also, they are as speedy as silverfishes. 

However, they are different when it comes to their preferred living style or space. Silverfish like to live in cold, humid, and dark, whereas these firebrats enjoy the heat and even thrive or exist in it. Their feet are fire-resistant, which gives them the ability to walk even on furnaces, or boilers, and on hot water pipes.

So, if you see a bug that looks like a silverfish but they are not hiding away from the sizzling sun, confirm it as a firebrat.

Similar Species – Firebrats

They are the other similar insect as with the silverfish. Two other silverfish quite common in Northern America are – Ctenolepisma longicaudatum and Ctenolepisma quadriseriatum.  

These Australian species which are most commonly referred to as the silverfish is a different type of insect. These firebrats are just like silverfish but if seen carefully they are mottled grey in colour and have a brown body.  

Black Silverfish

What looks like a silverfish but is black?

Normally what we see is a white silverfish but unlike a few, we might also see black silverfish which are actually firebrats, who are members of the same insect order as in the silverfish called Zygentoma. For this reason, they're quite similar to the silverfishes. In terms of their appearance, the firebrats are darker in colour than the silverfish and they are brown rather than being silver. 

Small Silverfish

Small silverfish can be spotted while you clean your bookshelves, they too can be a bookworm just like you!

Small silverfish can also be the baby silverfish that resides in any corner of the house. They are not a problem as such, like being on a bookshelf they can only try to eat your pages, but in vain. Well, when they are big that is when the problem starts. Adult silverfish can damage your book bindings and your stylish clothes by breeding in your cupboard, also they become unhygienic in this case. This time you need some prevention tips, thus we will discuss silverfish in the following section.  

How do Small Silverfish or Baby Silverfish Get Inside Your Buildings?

The silverfish have a flat body and their impressive running speed allows them to slip away quickly through the narrow cracks and crevices which are around the windows or doors. In this manner, they can easily enter your buildings. 

Silverfish Eggs

The Females lay up to three eggs at a single time, which hatches after a month or so. A single silverfish can live up to three years as the generations continue to grow.

Breeding in Wet or Damp Areas.

Silverfish have bristletails which prefer wet or damp areas and thus they enter homes through pipes and drains. They thrive well in dark, and cool basements and in bathrooms where there are high moisture levels. 

Problems Caused by Silverfish

The baby silverfish are generally harmless to humans. However, when they grow to an adult they will crawl into the bathtub or mattress across the floor which can be frightening. Their wide and varied diet makes them a problem in homes. Silverfish can feed on paper products that contain glue or paste, they can feed on starches in cereals, and the protein from the dried beef and from the pet food even.

Invading the Commercial Space as Well

Silverfish even invade the commercial spaces, like in restaurants and cafeterias. The workers working there might find silverfish eating the bags of flour in their pantries. In the storage and in the shipping facility employees sometimes discover the insects chewing the holes into the cardboard boxes. These pests can affect important documents and can also destroy office cabinets.

How Can You Prevent Silverfish?

Prevention Tips

In order to eliminate silverfish from your house, you need to follow these effective tips:

• Making sure that the adult silverfish cannot get inside, is the best and the foremost way to deter the brooding of silverfish.  

• You can use a dehumidifier to reduce the moisture content in your basement making sure fewer pests are invited.

• Seal down any cracks or fissures that lead to the outside and clean the gutters or the downspouts where they might hide.

• Check out Signs when baby silverfish are first infested:

• Seeing if there are any nymphs in your home which will indicate indoor breeding, is an obvious sign of infestation.

• These pests are nocturnal and will only eat after dark, so knowing the time will help you spot the active silverfish.

• Their bristletails occasionally eat individual fibres of fabric leaving yellow marks on them, especially on linen material and trace any yellow spots to find the silverfish.

• If you find your books damaged, that is an indication of silverfish breeding in your place. 

• Know the usual hiding place of the silverfish, which can be – in the kitchen or bathrooms, in the laundry area where you can find silverfish on clothes, in storage spaces, bookcases, etc. 

• Silverfish are attracted to the damp areas which have 75% to 95% humidity. Hence, it is recommended to reduce the humidity with dehumidifiers or with fans.

• Keep the closed rooms well ventilated, to prevent any dampness.

• Keep your room, storage space, and bathroom clean to avoid the brooding of these insects. 

Did You Know?

• Silverfish are the oldest living insect on this planet. They have thrived on the earth for over 400 million years!

• They live a very long life. These fishes live about 8 years.

• They cannot be easily killed for their slender body shifting quickly. 

• They have weird tastes. They like sweets in your kitchen and even like the taste of the paper in your cupboards.

• They are greatly aerobatic for their flat bodies. 

• Silverfish never cause any health disorder.

• Silverfish attract moisture, but they cannot live in water.

Silverfish are very common in households. Kill one only when they deserve to be killed. As silverfish do not cause any such harm. But if you maintain proper hygiene then this is the last insect you would like to see.