Reptiles Honor

Nature Study

Requirements

1. What characteristics must an animal have to be classified as a reptile.

   Answer: To be classified as a reptile, the animal must have: dry skin covered by horny scales, plates or scutes (of keratin), which waterproofs it and prevents water loss; be an ectothermic vertebrate (cold-blooded, regulating its temperature by the environment); breathe exclusively through lungs throughout its life; reproduce by shelled eggs (calcareous or flexible, an amniotic egg) laid on land, with internal fertilization; and have a heart with three chambers (two atria and a partially divided ventricle), except crocodilians, which have four chambers. — Ectothermy means they depend on the environment to regulate their body temperature. Reptiles were dominant in the Mesozoic Era (dinosaurs). Today about 11,000 species survive. Crocodilians have a heart with 4 chambers, more advanced, being evolutionarily close to modern birds.

2. What is the name of the substance that waterproofs the skin of reptiles?

   Answer: The substance is keratin, present in the scales and plates of reptiles. It forms a waterproof barrier that prevents water loss, allowing them to live even in dry deserts. — Keratin is a very resistant fibrous protein. In reptiles, it forms a dead outer layer that sheds periodically (ecdysis) — the famous skin shedding in snakes. Without keratin, reptiles would dry out in hours in dry environments. This adaptation is estimated to have arisen 320 million years ago.

3. What are the main orders into which the class of reptiles is divided? Cite 2 examples for each order.

   Answer: Four orders: Squamata (snakes and lizards — e.g. boa constrictor, iguana), Testudines (turtles — e.g. tortoise, freshwater turtle), Crocodilia (crocodiles and caimans — e.g. black caiman, Nile crocodile) and Rhynchocephalia (tuataras — e.g. Sphenodon punctatus). — Squamata is the largest order with 11,000+ species. Testudines have existed for 200 million years. Crocodilia is the only one with a 4-chambered heart. Rhynchocephalia has only 2 living species, both in New Zealand, and they are considered living fossils for having changed little since the dinosaurs.

4. Identify, in person or in images, a freshwater turtle, a sea turtle and a tortoise.

   Answer: Freshwater turtle: a freshwater turtle, with a flattened shell, lives in rivers and lakes. Sea turtle: a hydrodynamic shell, flippers like oars, lives in the sea. Tortoise: a land turtle, a high domed shell, thick legs with claws. — Freshwater turtles retract the head sideways (Pleurodira). Sea turtles such as the green sea turtle weigh up to 200 kg. Brazilian tortoises (Chelonoidis carbonaria, denticulata) can live more than 80 years. The three species have a shell but a completely distinct shape and lifestyle.

5. Give the names of 15 reptiles found in your region. State where they live, their feeding habits and their importance to the economy.

   Answer: Fifteen Brazilian ones: boa constrictor, anaconda, rattlesnake, jararaca (lancehead), urutu, true coral snake, gecko, iguana, tegu, tortoise, freshwater turtle, Amazon river turtle, black caiman, Pantanal caiman, sea turtle. Habitats: water, forest, savanna (cerrado). — Brazil has 800+ species of reptiles, being the fourth country in diversity. Anacondas control capybaras (and rural rats). Caiman leather generates millions in sustainable fashion. Amazon river turtles had food importance for indigenous peoples, and are now protected by IBAMA.

6. Cite 5 venomous reptiles of your region, describing each one in terms of fang location and geographic distribution.

   Answer: Five venomous Brazilian ones: jararaca (Bothrops jararaca, large and mobile front fangs - solenoglyphous, southeast); rattlesnake (Crotalus durissus, mobile front fangs - solenoglyphous, cerrado/caatinga and open fields); urutu (Bothrops alternatus, mobile front fangs - solenoglyphous, south/southeast); bushmaster (Lachesis muta, mobile front fangs - solenoglyphous, Amazon and Atlantic Forest); true coral snake (Micrurus sp., small and FIXED fangs at the FRONT of the mouth - proteroglyphous, occurring in almost the entire country). Note: coral snakes have fixed front fangs, not rear ones. — The jararaca causes 90% of snakebite accidents in Brazil. The bushmaster is the largest venomous snake in the Americas (up to 4 m). The true coral snake has neurotoxic venom — the false coral snake is harmless. Identifying it is vital: shouting the correct type to SAMU can save a life in a snakebite emergency.

7. State what to do if bitten by a venomous snake.

   Answer: Stay calm and keep the victim still so as not to speed up circulation. Wash the area with water and soap. Do not cut, do not use a tourniquet, do not suck out the venom. Take them immediately to the hospital or call SAMU 192, reporting the type of snake. — The Butantan Institute has produced Brazilian antivenom serums since 1901. Time is vital — every minute without serum increases tissue damage. Tourniquet and cutting are forbidden: they cause more harm than help. Photograph the snake (from a distance) for identification at the hospital if possible.

8. State what to do if bitten by a non-venomous snake.

   Answer: Wash the wound with water and neutral soap. Apply antiseptic and protect with a clean dressing. Check whether your tetanus vaccine is up to date. Watch for signs of infection (redness, swelling, heat) in the following days. — Non-venomous snakes (boa constrictor, anaconda, vine snake) cause only a mechanical wound. The greater risk is bacterial infection from the bacteria in the snake's mouth, or tetanus. The tetanus vaccine needs a booster every 10 years. Deep bites require medical evaluation to avoid injury.

9. Complete one of the following tasks:
   • Compare lizards, snakes, turtles, and crocodiles regarding their way of life, variation in eyes and ears, teeth, heart, lungs, limbs, tail, and scales.
   • Keep a small reptile in a terrarium and write a report on its care for at least 3 months. (When fulfilling this requirement, be sure you are not breaking any law in your country).

   Answer: Choose one: 1) Compare in writing the 4 groups across all 9 listed criteria (way of life, eyes, ears, teeth, heart, lungs, limbs, tail, scales). — The comparison deepens taxonomy. Snakes have no limbs or external ears, but they detect vibrations. Crocodiles have a 4-chambered heart (unique among reptiles). Turtles and crocodiles have large scales; lizards have small ones. Keeping a reptile requires knowing local environmental laws.

10. Be able to tell 2 Bible stories in which a reptile played an important role.

    Answer: Two Bible stories with reptiles in an important role: (1) The serpent in Eden (Genesis 3) — the serpent, used by Satan, tempted Eve to eat of the forbidden fruit, leading Adam and Eve into sin and the fall of humanity. (2) The bronze serpent in the wilderness (Numbers 21:4-9) — when the people of Israel were bitten by venomous serpents as punishment for their murmuring, God told Moses to make a bronze serpent and place it on a pole; everyone who looked at it was healed, a symbol of Christ lifted up on the cross (John 3:14-15). — In Genesis 3, the serpent is a symbol of Satan (Revelation 12:9). The bronze serpent prefigured the cross of Christ (John 3:14). Other stories: Aaron's staff turned into a snake (Exodus 7:10) and Paul bitten by a viper in Malta without suffering harm (Acts 28:3-6). Reptiles appear several times in the Bible.