The newt, between land and water

One of the most discreet animals, the newt, leads its peaceful life between stagnant water and forest cover, to the rhythm of the seasons. More and more rare, some of its species are classified in the Bern Convention; it is thus necessary to protect this small amphibian to preserve it.

Who are you?

There are several species of newts all belonging to the genus Triturus: the palmate newt (Lissotriton helveticus), the spotted newt (Lissotriton vulgaris), the crested newt (Lissotriton cristallus), the marbled newt (Lissotriton marmoratus) and the alpine newt (Lissotriton alpestris).

Each of these species lives in a particular habitat between water and land throughout their life cycle.

The newts are urodelic amphibians, that is to say that they have a tail, which in their case is flattened on each side. They have a larval life which takes place entirely in water, then an adult life shared between dry land, ponds, water holes and small calm rivers. Their rhythm is very linked to the climatic conditions; In winter, they begin a period of rest, generally on the ground under a stone or plants if the winter is not very rigorous. In altitude, the winter can be spent under water.

Newts are carnivorous and feed on small mollusks, worms, mosquito larvae, frog eggs and insects.

Breeding always takes place in aquatic environments around April. After a nuptial parade, the male deposits a spermathopore at the bottom of the water which will be absorbed by the cloaca of the female. The latter will then lay one or two eggs which she will hang on the surrounding aquatic plants. The larva, similar to a tadpole, will develop in the water during 3 months until the end of the summer, period when the metamorphosis will be complete and when the young newt will leave the water to begin its adult life. It will generally spend the winter on land, then will dive back into the water for its mating. This is followed by an amphibious life until the next winter.

The different species of newt

The marbled newt is present in the forest environments of the South-West and the West of the country. It is recognizable by its green body punctuated with black spots and its lighter belly. It can reach 15 cm in length. This newt appreciates the sun and living waters. It can reproduce with the crested newt which appreciates the same living conditions. This last one has a grey and brown spotted skin, warty like a toad and presents two crests, a caudal and a very crenellated dorsal. Its belly and the inside of its legs are orange. It is found in a line from Lyon to La Rochelle. These two species are listed in Appendix II of the Bern Convention.

The palmate newt has webbed hind legs and can be recognized by its rounded snout and its greenish body spotted with black. Small in size, it does not exceed 9 cm despite its tail extended by a short filament. It is present on all the territory except Corsica and the extreme South-East.

The alpine newt lives in stagnant waters sheltered from the sun, north of a line that extends from Avignon to Saint-Malo. This bluish-gray newt with an orange-brown belly can live at altitude, up to 2500 m. The male does not exceed 8 cm while the female can reach 12 cm in length. During the reproduction period, the male is decorated with bright colors.

The shubunkin, a small and colorful fish

The Shubukin (Carassius auratus) is a fish of the Cyprinidae family that has a similar shape to the common goldfish, but is smaller and more colorful. Native to China, the Shubunkin likes to live in fresh water with little movement and in streams with little current.

Description

Shubukin are calico, mostly bluish with extensive red spots and smaller black spots scattered throughout their body. Adults they measure about 25 cm. There are three varieties of Shubukin: the Bristol Shubukin, the American Shubukin which is more streamlined and has less fin length than the previous one, and the London Shubukin which is a little smaller, with a shorter, less wide and less lobed tail fin than its Bristol cousin, which can reach more than half of the total size of the fish. The pectoral and pelvic fins are even numbers, while the dorsal, anal and caudal fins are odd numbers. Females are generally much larger.

Habitat and feeding

In its native country, the Shubunkin lives in fresh and calm water. It is resistant to cold but not to strong frosts. You can install it in your pond in privileged areas where it will feed on small elements found in the ground which it loves to dig. It is omnivorous and is interested in mosquito larvae as well as algae. In cold regions, it will be necessary to bring it into an aquarium during the winter, making sure to provide a minimum of 20 liters of water per individual. Feed it with pellets and chopped cooked vegetables.

Life cycle

In spring when the temperature rises, the spawning period begins for fish that have reached sexual maturity, which is about two years old. The male then adorns himself with small white buttons on the opercules as well as on the first ray of the pectoral fins.

After some parades between the male and the female, the female deposits the eggs on the available supports then a few moments after the male fertilizes the eggs by letting escape its milt. The eggs adhere then to the plants and the surrounding surfaces. Incubation can begin, after three to six days depending on the water temperature a larva will emerge and sink while the swim bladder is formed (2 to 4 days). The small fish will then find the strength to capture an air bubble which will allow it to swim to feed itself and then if the conditions allow it to live a long life (20 years).

The awakening of the amphibians

Every year, between February and April, some amphibians move from their wintering site to their breeding site in wetlands. A journey that involves many dangers that many of them will not resist.

Cycle of amphibians

Amphibians, unlike mammals, do not have the possibility to regulate their internal temperature themselves, which always depends on the surrounding environment. Their energetic needs being less, they allow periods of fasting and therefore hibernation as soon as the temperatures become too cold to live actively. In autumn, amphibians migrate towards their wintering site, most of the time towards terrestrial sites in wooded areas. They then bury themselves under leaves or settle in crevices of tree trunks or rocks. In the spring, they slowly wake up and take the path in the other direction towards a wetland suitable for reproduction.

A perilous migration

Toads, salamanders or newts leave their wintering grounds at the first warm nights of spring to reach the pond or lake where they can reproduce.

Unfortunately, for many of them, this will be their last trip. In the past, they were only subject to their natural predators (birds, snakes, small mammals...), but now they are victims of the worst of them: Man.

Their journey is nowadays more and more full of pitfalls of all kinds: roads to cross, garden fences... Coming out of their sleep, their movement is also slower. Few humans have scruples to run over these little creatures when they are driving their vehicles! However, some of these amphibians are protected and endangered. If you pass them on the road, avoid them and help them to reach the other side of the road to allow them to procreate.

Devices are sometimes set up along the roadside in some regions to capture them in order to move them to the other side of the road to give them a chance to reproduce. Associations are also set up, creating events bringing together their members who come to cross the amphibians during the migrations, whether they are spring or autumn. Finally, there are 'crapoducs' on certain roads. These specific arrangements in the form of tunnels permanently installed under the road allow amphibians to cross without being crushed.

Let's not forget that amphibians, like toads, are also friends of the gardener and help limit the proliferation of certain biting insects like mosquitoes. If you come across them on the road, avoid them and help them get to the other side of the road so they can procreate. 

The goldfish, a classic of the pond

The goldfish is a classic in outdoor ponds. A member of the carp family, this fish is easy to live with in temperate regions since it can withstand progressive temperature changes of a significant amplitude.

The goldfish originates from China where it has been regularly and selectively bred for over a thousand years. Originally, the goldfish was a rather dull Asian carp which gained in color through crossbreeding and hybridization.

From the Cyprinidae family, it is a close relative of the carp while presenting much more restricted measurements what destines it particularly to small outdoor ponds and indoor aquariums.

Like the carp, the goldfish comes in a multitude of varieties. The most common goldfish have a stocky and compact body that is entirely orange-red. This variety usually reaches a maximum of 25 cm in aquariums but can reach up to 40 cm in outdoor ponds.

All these fish have the characteristic to reproduce perfectly and easily in outdoor ponds, less easily in aquariums because of the promiscuity and the voracity of the adults.

Very resistant to temperature changes, goldfish can easily withstand a winter outside at -10°C as long as the temperature drop is not too fast. In the same way, it can adapt to strong heat as long as the rise in temperature is gradual.

This is not the case for the goldfish variety known as "sail tails" or comets, which do not tolerate large temperature changes outside!

Many other varieties have been created by man over the centuries, some of which are only red in name! The most eccentric ones are the lionhead goldfish which are distinguished from the others by protuberances on the top of the head, the telescopic goldfish with exorbitant eyes, the shubukin with very long dorsal and caudal fins, etc. The classic colors are red-orange but many species mix several colors: white and red, golden yellow and white, intense black...

The longevity of goldfish is generally 5 to 10 years on average in aquariums while in outdoor ponds, they can happily exceed 15 years very commonly. Goldfish grow throughout their lives.

The caddisfly, the wood holder of the pond

They populate the bottom of the ponds, hide under the stones of the streams, slip into the rushes of the ponds... The carrion beetle, the wood dragger, the alder beetle, the carpenter beetle, the caddisfly form a family of common insects, with a half aquatic, half aerial life cycle.

A mason insect

It reveals its presence when it moves, some debris of the pond seeming to set in motion. The larva of Phrygane lives in small tubes from 2 to 4 cm long, made of various materials. Of the group of Integripalpia these mobile Trichoptera of greenish tint let exceed of their sheath a short and broad head with the eyes little marked, with the short antennas, with the crushing mouth. The six pairs of legs are visible, the first pair rather short, the others long and thin. The elongated abdomen ends with a pair of hooks hidden in the sheath.

Cousins of the butterflies, the Phryganes do not weave a nymphal cocoon but a permanent shelter.

A house of silk and eclectic materials

The small larvae of caddisflies build their first shelter very early. The front legs seize and sort the available organic and mineral materials, the mouth apparatus cuts them, adjusts them. Two specific glands near the mouth produce a liquid and sticky silk, cementing the whole, lining the inside of the tube for an optimal comfort.

The finished sleeve forms a funnel and remains open at both ends. Blending into the environment, it offers perfect camouflage and effective protection. It will be different according to the materials available, and especially according to the species of caddisflies, each one having its preferences.

To each species its sheath

If certain species of caddisflies make a sheath of leaves cut in large pieces assembled in an elegant tiling, others opt for fine strips, assembled all bristled; others will choose twigs cut and piled up in regular spiral; others still will agglomerate shells of planorbe.

To better resist the current, the caddisflies will weight themselves with tiny pebbles. Each species will thus choose its style of sheath. If their favorite materials are missing, they will adapt, even choosing small pieces of plastic, beads, colored fabrics, identification by the sheath alone becoming uncertain.

A long year under water

Sheltered in their sheath, the larvae will live for most species a good year in unpolluted, well oxygenated water. The external gills, branched or digested, characteristic of each species, are arranged all along their abdomen and allow them to breathe the dissolved oxygen of water. This breathing is completed by a permeability of the tegument, and optimized by the creation of a current circulating between the two ends of the sheath. Conferring to this frame, in addition to the protective and camouflage role, a physiological function of first importance.

Diversified menus, a fast growth and an adjustable sheath

The larvae of caddisflies move on their four long locomotor legs. Detritus feeders in general, they scrape the substrates, crush the organic matter in decomposition. Helped by their front legs, they capture tiny particles in suspension, algae, invertebrates...

It will take them less than 4 months, up to 7 successive moults, to reach their maximum size. And with each moult, they will have to enlarge their sheath. Widening it on the head side while cutting the opposite small end.

A swimming nymph

Its maximum size reached, the larva is ready to metamorphose. It closes the two ends of its sheath with a membrane of woven silk, and pads its interior. The wing sheaths of the nymph develop, the long antennas of the future adult are folded in ventral position. Also appear dorsal spines, a pair of mandibles, swimming silks on the second pair of legs: the spines will enable him to release itself from its nymphal sheath, the mandibles to cut the trapdoor of exit, the silks to swim towards the surface. Where it will cling, one night, to an emerged substrate, then will metamorphose into adult, and will take its flight.

An adult with silk wings

Brownish to beige, the adult caddisflies are easily recognized. Elongated, of average size, 2 to 4 cm, they carry long and fine antennas projected towards the front, large well developed eyes. They could look like moths. But unlike their distant cousins they fold their four wings in the form of a roof and carry many bristles, sometimes long bangs. Trichoptera meaning silk wings. Also they do not have a spiral proboscis. Neither do they have mandibles. Just like Ephemera, the adult caddisflies do not eat, devoting themselves exclusively to their reproductive task.

An ephemeral life

The spring or summer appearance of caddisflies is short-lived, the time of a pause in a cave to complete their sexual maturity for some species, a few days for others. Briefly, males and females meet. The eggs will be laid in clusters on submerged plants, or just on the surface, as soon as they hatch the larvae enter the aquatic environment. The adults are stranded on the surface of the water, for the greatest delight of trout and other predators.

Common, diversified, caddisflies play an important role in aquatic habitats. Food source for many animals, fish, invertebrates, but also birds, they are also appreciated by fishermen, for the larvae as bait, the adults serving as a model for fly fishing.

The mosquito, a blood drinker in the pond

Frogs, garter snakes, turtles, none of the inhabitants of the pond escape the bites of adult mosquitoes. But they feast on their aquatic larvae, and few of them escape.

The world's ponds busy

Wetlands around the world are home to mosquitoes. Their eggs, and then their larvae, live in the water. The winged adults, while often foraging, are in search of blood, in all vertebrates. The inhabitants of the banks of the pond know them only too well.

In Europe, they are mainly solicited by Aedes, rather in temporary wetlands, Culex and some Anopheles in stagnant waters. In their family Culicidae we will also find the Coquillettidia, with a very original respiratory mode.

Aquatic larvae, air breathing

Mosquito larvae live in water but continue to breathe like terrestrial insects. They look for air on the surface of ponds, positioning themselves head down, vertically, for the Culex. A well known posture where we see the small silhouettes grouped, long and thin, as if hooked to the surface by their respiratory siphon. They stay there, breathing in and out. The Anopheles, without siphon, will lie under the surface allowing the air to circulate in their tracheas. And the Coquillettidia will never come to the surface. But then? From their pointed respiratory siphon they pierce the tissues of aquatic plants, and take the necessary air from them.

They feed on waste, nectar and a little blood

From the larva to the adult, from the male to the female, the feeding of mosquitoes differs completely. The adult female is well known for biting, injecting an anti-coagulant, and sucking blood from her prey. All this to bring to maturity her young, eggs that she will deposit delicately on the surface of the water.

Out of this period, the adults fly from flowers to flowers, feeding on their nectar and pollinating them. The larvae will spend their few weeks of aquatic life filtering and cleaning the water. They shake their mouth bristles, creating a water current, feeding on floating microparticles.

Larvae wriggle, adults fly

A mosquito larva has no legs, the observer approaching a tank of water will see them wriggling to disappear towards the bottom, helped by bristles arranged all along the body. The nymph, a strange silhouette with a large thorax floating in the middle of the larvae, is equipped with a swimming paddle at the end of its abdomen. The adult, better known, has a single pair of wings and two pendulums, like all members of its group Diptera.

Males and females, aquatic meetings

The females, with the hematophagous diet essential to the development of the eggs, lay eggs on the surface of the water. They float in small irregular groups in Anopheles, in rafts in Culex and Aedes. A first larva hatches, it will moult three times before turning into a nymph. With cycles of a few days to a few weeks, depending on the species and climatic conditions. Mobile, with a large dark thorax from which emerges a small breathing tube, the nymph will give birth to the winged adult at the surface.

Mosquitoes are not very popular, and often the idea of the pond, of the body of water, is associated with them, with the fear of seeing them invade our gardens. However, in the pond many predators devour them, and dragonflies spare few adults... They are thus essential to this ecosystem!