Amazing Animals - BioNotes

Most Common Larval Stages

Phylum	Class	Larval Stage	Found At Stage	Key Features
Porifera	-	Amphiblastula	Early development	Free-swimming, symmetrical, with cells destined to become adult structures.
Cnidaria	Anthozoa	Planula	Early development	Free-swimming, elongated, ciliated larva, develops into a polyp.
Cnidaria	Scyphozoa	Ephyra	After polyp stage	Precursor to the adult jellyfish, small and star-shaped.
Mollusca	Gastropoda	Veliger	After trochophore	Possesses beginnings of a foot, shell, and mantle.
Annelida	Polychaeta	Trochophore	Early development	Free-swimming, spherical or pear-shaped, with a band of cilia.
Echinodermata	Echinoidea	Pluteus	After blastula	Elongated body with skeletal rods, develops into sea urchins.
Echinodermata	Asteroidea	Bipinnaria	After blastula	Free-swimming, bilateral symmetry, develops into starfish.
Arthropoda	Insecta	Larva (e.g., caterpillar, maggot)	After egg	Highly variable, often worm-like, undergo metamorphosis into adults.
Arthropoda	Crustacea	Nauplius	Early development	First larval stage, with a simple body and three pairs of appendages.
Arthropoda	Crustacea	Zoea	After nauplius	More complex, with developing limbs and often a spine.
Chordata	Ascidiacea (Tunicata)	Tadpole	Early development	Resembles a tadpole, with a notochord and a tail, for swimming.

Other Larval Stages

Phylum	Class	Larval Stage	Found At Stage	Key Features
Annelida	Oligochaeta	No distinct larva	-	Direct development, lacks a free-swimming larval stage.
Mollusca	Bivalvia	Glochidium	After trochophore	Parasitic on fish, hooks for attachment to gills or fins.
Mollusca	Cephalopoda	Paralarva	Early development	Resembles a miniature adult but lives in the plankton.
Echinodermata	Holothuroidea	Auricularia	After blastula	Elongated body with ciliary bands, develops into sea cucumbers.
Echinodermata	Crinoidea	Pentacrinoid	After doliolaria	Stalked larva, anchors to substrate before becoming a free-moving adult.
Arthropoda	Merostomata (Horseshoe Crabs)	Trilobite larva	After egg	Named for its resemblance to trilobite fossils, swims before settling.
Arthropoda	Decapoda	Mysis	After zoea	Transitional stage to adult, resembles a shrimp, more developed appendages.
Bryozoa	Gymnolaemata	Cyphonautes	Early development	Triangular, bivalve-like shell, planktonic, disperses for new colonies.
Nemertea	-	Pilidium	Early development	Unique, helmet-shaped, develops directly into the juvenile worm.
Brachiopoda	-	Lophophore larva	Early development	Bears lophophore for feeding; not all species have a free-living larval stage.
Chordata	Cephalochordata	Amphioxus larva	After egg	Resembles the adult lancelet, but smaller and transparent.
Platyhelminthes	Trematoda	Miracidium	After egg	Infects a snail host, ciliated for swimming.
Platyhelminthes	Cestoda	Oncosphere	After egg	Infective stage to the intermediate host, has hooks for penetration.
Nematoda	-	Dauer larva	Variable	Stress-resistant, non-feeding stage in the life cycle of some nematodes.
Porifera	-	Parenchymula	Early development	Free-swimming, solid, develops into a sponge upon settling.
Cnidaria	Hydrozoa	Hydra larva	After planula	Settles to form a new polyp, direct development from planula.
Urochordata	-	Thaliacea larva	Early development	Free-swimming, develops directly into a salp.
Arthropoda	Amphipoda	Juvenile	After nauplius	Direct development in some species, bypassing typical larval stages.
Arthropoda	Echinodermata	Brachiolaria	After bipinnaria	Second larval stage in starfish, develops arms and begins to settle.

Chordate Larval Stages

Subphylum/Class	Common Name	Larval Stage	Key Features
Cephalochordata	Lancelets	Amphioxus larva	Resembles the adult but smaller; exhibits basic chordate features such as a notochord and dorsal nerve cord.
Urochordata	Sea squirts	Tadpole larva	Free-swimming, has a notochord and nerve cord during this stage; undergoes drastic metamorphosis to sessile adult.
Ascidiacea	Ascidians	Tadpole larva	Similar to sea squirts; the larval stage is crucial for dispersal.
Thaliacea	Salps	Thaliacea larva	Planktonic, free-swimming; undergoes simple metamorphosis into chain-forming adult salps.
Larvacea	Appendicularians	No distinct larval stage	Direct development; retains larval characteristics throughout its life.
Osteichthyes (Bony Fish)	Various species	Larvae/fry	Development stages include yolk sac larvae, fry, and then juveniles as they grow; stages vary widely among species.
Amphibia	Frogs, salamanders, newts	Tadpole	Aquatic, gill-breathing, undergoes metamorphosis to air-breathing adult; morphology changes significantly.
Reptilia	Certain aquatic reptiles	Hatchling	No distinct larval stage, but sea turtles and some lizards have critical early life stages for dispersal and growth.
Aves	Seabirds, waterfowl	Chick	Direct development, but chicks in species like ducks are precocial and ready to swim soon after hatching.
Mammalia	Monotremes	Puggle	Monotremes lay eggs, and the young, called puggles, hatch and continue to develop outside the egg.
Actinopterygii	Ray-finned fishes	Larvae/fry	Transition from larval stage to juvenile is marked by development of fins and scales; timing varies by species.
Chondrichthyes	Sharks, rays	Pup	Many are born/hatched as miniature adults, but some have a distinct free-swimming larval stage known as a pup.
Myxini	Hagfish	Leptocephalus-like larva	Transparent, eel-like larva; not well-studied due to deep-sea habitat.
Petromyzontida	Lampreys	Ammocoete	Blind, burrowing larval stage that filter feeds in sediment; undergoes metamorphosis into adult lamprey.
Sarcopterygii	Lungfish	No distinct larval stage	Direct development, but juvenile lungfish resemble adults and are adapted to both aquatic and eventual terrestrial life.

Unique among animals

Uniqueness	Common Name	Scientific Name	Phylum	Uniqueness Explanation
Electric	Electric Eel	Electrophorus electricus	Chordata	Capable of generating electric shocks to navigate and locate prey.
Transparent	Glass Frog	Centrolene spp.	Chordata	Possesses translucent skin, allowing its internal organs to be visible.
Immortal	Turritopsis Jellyfish	Turritopsis dohrnii	Cnidaria	Has the ability to revert to its juvenile form after reaching adulthood, essentially achieving biological immortality.
Walking Fish	Mudskipper	Periophthalmus spp.	Chordata	Adapted to terrestrial life and capable of "walking" on land using their pectoral fins and breathing through their skin.
Four-Winged	Dragonfly	Order Odonata	Arthropoda	Exhibits four wings, with two pairs of intricately veined and transparent wings, enabling agile flight and maneuverability.
Shape-Shifting	Mimic Octopus	Thaumoctopus mimicus	Mollusca	Demonstrates exceptional camouflage skills by changing its color, shape, and texture to mimic other animals for defense and hunting.
Venomous	Blue-Ringed Octopus	Hapalochlaena spp.	Mollusca	Carries highly potent venom, producing striking blue rings as a warning sign, making it one of the world's most venomous marine creatures.
Bioluminescent	Firefly	Lampyridae family	Arthropoda	Generates light through bioluminescence, emitting flashes to attract mates or communicate with other fireflies.
Egg-Laying Mammal	Platypus	Ornithorhynchus anatinus	Chordata	Exhibits characteristics of both mammals and reptiles, including laying eggs, producing milk, and possessing venomous spurs.
Flying Squid	Japanese Flying Squid	Todarodes pacificus	Mollusca	Capable of propelling itself out of water using jet propulsion, enabling short bursts of flight above the ocean's surface.
Invisible	Glasswing Butterfly	Greta oto	Arthropoda	Possesses transparent wings that make it appear almost invisible, aiding in camouflage and protection from predators.
Extinct	Dodo	Raphus cucullatus	Chordata	A flightless bird that went extinct due to human activities, serving as a notable example of the impact of human-induced extinction.
Electric	Electric Ray	Torpedo spp.	Chordata	Possesses specialized electric organs that generate electric shocks for defense and stunning prey.
Six-Legged	Star-Nosed Mole	Condylura cristata	Chordata	Features a unique star-shaped snout with numerous sensitive appendages, allowing it to navigate and hunt in dark, aquatic environments.
Regenerating	Axolotl	Ambystoma mexicanum	Chordata	Capable of regenerating lost body parts, including limbs, spinal cord, heart, and other organs, making it a remarkableregenerative species.
Flying	Flying Squirrel	Pteromyini family	Chordata	Possesses a membrane called a patagium that stretches between its limbs, enabling it to glide through the air.
Camouflaged	Leafy Sea Dragon	Phycodurus eques	Chordata	Exhibits elaborate leaf-like appendages on its body, providing exceptional camouflage that helps it blend with seaweed and kelp forests.
Magnetized	Magnetite-Tailed Termite	Termes oblongus	Arthropoda	Contains high levels of magnetite in their bodies, allowing them to navigate and orient themselves using Earth's magnetic field.
Luminous	Anglerfish	Ceratiidae family	Chordata	Possesses a bioluminescent lure called an illicium that dangles in front of its mouth to attract prey in the dark depths of the ocean.
Barrel-Shaped	Pufferfish	Tetraodontidae family	Chordata	Has the ability to inflate its body into a spiky ball-like shape as a defense mechanism against predators.
Armored	Armadillo	Dasypodidae family	Chordata	Covered in a hard, protective shell made of bony plates called scutes, providing defense against predators.
Antlered	Chinese Water Deer	Hydropotes inermis	Chordata	Possesses long canine teeth, or tusks, that resemble antlers, which are used for territorial displays and combat.
Gliding	Flying Frog	Rhacophorus reinwardtii	Chordata	Utilizes large webbed feet and flaps of skin between its limbs to glide through the air from tree to tree.
Pouched	Kangaroo	Macropus genus	Chordata	Females have a pouch in their abdomen where they carry and nurse their underdeveloped young called joeys.
Two-Headed	Two-Headed Snake	Bicephalus spp.	Reptilia	Rare condition where the snake has two heads, which can sometimes lead to challenges in coordination and feeding.
Hairy	Tarantula	Theraphosidae family	Arthropoda	Covered in dense hair-like setae, which aids in sensing the environment and provides a defense mechanism against predators.
Suction-Cupped	Octopus	Octopoda order	Mollusca	Possesses suction cups on its tentacles, allowing it to grip and manipulate objects, as well as aid in locomotion and capturing prey.
Shell-Breaking	Coconut Crab	Birgus latro	Arthropoda	Has incredibly strong claws that can crack open coconuts, earning its name, and allowing it to access food and shelter.
Acid-Spraying	Bombardier Beetle	Brachinini tribe	Arthropoda	Can produce and eject a noxious, hot chemical spray from its abdomen as a defensive mechanism against predators.
Boneless	Jellyfish	Medusozoa class	Cnidaria	Lacks a skeleton or bones, having a gelatinous body structure that allows them to move and swim through the water.
One-Horned	Narwhal	Monodon monoceros	Chordata	Uniqueness
Electric	Electric Eel	Electrophorus electricus	Chordata	Capable of generating electric shocks to navigate and locate prey.
Transparent	Glass Frog	Centrolene spp.	Chordata	Possesses translucent skin, allowing its internal organs to be visible.
Immortal	Turritopsis Jellyfish	Turritopsis dohrnii	Cnidaria	Has the ability to revert to its juvenile form after reaching adulthood, essentially achieving biological immortality.
Walking Fish	Mudskipper	Periophthalmus spp.	Chordata	Adapted to terrestrial life and capable of "walking" on land using their pectoral fins and breathing through their skin.
Four-Winged	Dragonfly	Order Odonata	Arthropoda	Exhibits four wings, with two pairs of intricately veined and transparent wings, enabling agile flight and maneuverability.
Shape-Shifting	Mimic Octopus	Thaumoctopus mimicus	Mollusca	Demonstrates exceptional camouflage skills by changing its color, shape, and texture to mimic other animals for defense and hunting.
Venomous	Blue-Ringed Octopus	Hapalochlaena spp.	Mollusca	Carries highly potent venom, producing striking blue rings as a warning sign, making it one of the world's most venomous marine creatures.
Bioluminescent	Firefly	Lampyridae family	Arthropoda	Generates light through bioluminescence, emitting flashes to attract mates or communicate with other fireflies.
Egg-Laying Mammal	Platypus	Ornithorhynchus anatinus	Chordata	Exhibits characteristics of both mammals and reptiles, including laying eggs, producing milk, and possessing venomous spurs.
Flying Squid	Japanese Flying Squid	Todarodes pacificus	Mollusca	Capable of propelling itself out of water using jet propulsion, enabling short bursts of flight above the ocean's surface.
Invisible	Glasswing Butterfly	Greta oto	Arthropoda	Possesses transparent wings that make it appear almost invisible, aiding in camouflage and protection from predators.
Extinct	Dodo	Raphus cucullatus	Chordata	A flightless bird that went extinct due to human activities, serving as a notable example of the impact of human-induced extinction.
Electric	Electric Ray	Torpedo spp.	Chordata	Possesses specialized electric organs that generate electric shocks for defense and stunning prey.
Six-Legged	Star-Nosed Mole	Condylura cristata	Chordata	Features a unique star-shaped snout with numerous sensitive appendages, allowing it to navigate and hunt in dark, aquatic environments.
Regenerating	Axolotl	Ambystoma mexicanum	Chordata	Capable of regenerating lost body parts, including limbs, spinal cord, heart, and other organs, making it a remarkable regenerative species.
Flying	Flying Squirrel	Pteromyini family	Chordata	Possesses a membrane called a patagium that stretches between its limbs, enabling it to glide through the air.
Camouflaged	Leafy Sea Dragon	Phycodurus eques	Chordata	Exhibits elaborate leaf-like appendages on its body, providing exceptional camouflage that helps it blend with seaweed and kelp forests.
Magnetized	Magnetite-Tailed Termite	Termes oblongus	Arthropoda	Contains high levels of magnetite in their bodies, allowing them to navigate and orient themselves using Earth's magnetic field.
Luminous	Anglerfish	Ceratiidae family	Chordata	Possesses a bioluminescent lure called an illicium that dangles in front of its mouth to attract prey in the dark depths of the ocean.
Barrel-Shaped	Pufferfish	Tetraodontidae family	Chordata	Has the ability to inflate its body into a spiky ball-like shape as a defense mechanism against predators.
Armored	Armadillo	Dasypodidae family	Chordata	Covered in a hard, protective shell made of bony plates called scutes, providing defense against predators.
Antlered	Chinese Water Deer	Hydropotes inermis	Chordata	Possesses long canine teeth, or tusks, that resemble antlers, which are used for territorial displays and combat.
Gliding	Flying Frog	Rhacophorus reinwardtii	Chordata	Utilizes large webbed feet and flaps of skin between its limbs to glide through the air from tree to tree.
Pouched	Kangaroo	Macropus genus	Chordata	Females have a pouch in their abdomen where they carry and nurse their underdeveloped young called joeys.
Two-Headed	Two-Headed Snake	Bicephalus spp.	Reptilia	Rare condition where the snake has two heads, which can sometimes lead to challenges in coordination and feeding.
Hairy	Tarantula	Theraphosidae family	Arthropoda	Covered in dense hair-like setae, which aids in sensing the environment and provides a defense mechanism against predators.
Suction-Cupped	Octopus	Octopoda order	Mollusca	Possesses suction cups on its tentacles, allowing it to grip and manipulate objects, as well as aid in locomotion and capturing prey.
Shell-Breaking	Coconut Crab	Birgus latro	Arthropoda	Has incredibly strong claws that can crack open coconuts, earning its name, and allowing it to access food and shelter.
Acid-Spraying	Bombardier Beetle	Brachinini tribe	Arthropoda	Can produce and eject a noxious, hot chemical spray from its abdomen as a defensive mechanism against predators.
Boneless	Jellyfish	Medusozoa class	Cnidaria	Lacks a skeleton or bones, having a gelatinous body structure that allows them to move and swim through the water.
One-Horned	Narwhal	Monodon monoceros	Chordata	Possesses a long, spiral tusk, which is actually a specialized tooth,used for various purposes including foraging, defense, and social signaling. The tusk can grow up to several meters in length and is primarily found in males.

Fish or not?

Organism	Scientific Name	Phylum	Is Fish?
Hagfish	Myxini	Chordata	Yes
Lungfish	Dipnoi	Chordata	Yes
Coelacanth	Coelacanthiformes	Chordata	Yes
Catfish	Siluriformes	Chordata	Yes
Jellyfish	Scyphozoa	Cnidaria	No
Silverfish	Lepisma saccharina	Arthropoda	No
Shellfish	Various species	Mollusca, Arthropoda	No
Starfish	Asteroidea	Echinodermata	No
Swordfish	Xiphias gladius	Chordata	Yes
Flyingfish	Exocoetidae	Chordata	Yes
Goldfish	Carassius auratus	Chordata	Yes
Bluefish	Pomatomus saltatrix	Chordata	Yes
Monkfish	Lophiiformes	Chordata	Yes
Butterflyfish	Chaetodontidae	Chordata	Yes
Clownfish	Amphiprionidae	Chordata	Yes
Lionfish	Pterois volitans	Chordata	Yes
Cuttlefish	Sepiida	Mollusca	No
Remora fish	Echeneidae	Chordata	Yes
Mudskipper	Periophthalmus barbarus	Chordata	Yes
Anchovy	Engraulidae	Chordata	Yes
Devilfish	Mobula spp.	Chordata	Yes
Drumfish	Sciaenidae	Chordata	Yes
Cowfish	Ostraciidae	Chordata	Yes
Bonefish	Albula spp.	Chordata	Yes
Sunfish	Mola mola	Chordata	Yes
Greenland shark	Somniosus microcephalus	Chordata	Yes
Suckerfish	Echeneis naucrates	Chordata	Yes
Parrotfish	Scaridae	Chordata	Yes
Guppy	Poecilia reticulata	Chordata	Yes
Porcupinefish	Diodon hystrix	Chordata	Yes
Stonefish	Synanceia verrucosa	Chordata	Yes
Bullhead	Cottus spp.	Chordata	Yes
Plaice	Pleuronectes platessa	Chordata	Yes
Squirrelfish	Holocentrus spp.	Chordata	Yes
Grunion	Leuresthes tenuis	Chordata	Yes
Wrasse	Labridae	Chordata	Yes

Misleading “sea”

Organism	Scientific Name	Phylum
Seapen	Pennatulacea	Cnidaria
Seahorse	Hippocampus spp.	Chordata
Sea urchin	Echinoidea	Echinodermata
Sea star	Asteroidea	Echinodermata
Sea turtle	Testudines	Chordata
Sea anemone	Actiniaria	Cnidaria
Sea lion	Otariidae	Chordata
Sea otter	Enhydra lutris	Chordata
Sea cucumber	Holothuroidea	Echinodermata
Sea sponge	Porifera	Porifera
Sea slug	Nudibranchia	Mollusca
Sea spider	Pycnogonida	Arthropoda
Sea dragon	Phycodurus eques	Chordata
Sea eagle	Haliaeetus spp.	Chordata
Sea snake	Hydrophiidae	Chordata
Sea bass	Morone spp.	Chordata
Sea lily	Crinoidea	Echinodermata
Sea bream	Sparidae	Chordata
Sea lamprey	Petromyzontida	Chordata
Sea fan	Alcyonacea	Cnidaria
Sea cow	Sirenia	Chordata
Sea butterfly	Limacina helicina	Mollusca
Sea angel	Clione limacina	Mollusca
Sea squirt	Ascidiacea	Chordata
Sea lice	Caligidae	Arthropoda
Sea hare	Aplysiomorpha	Mollusca
Sea cucumber	Synaptula hydriformis	Echinodermata
Sea spider	Nymphon spp.	Arthropoda
Sea moth	Pegasidae	Chordata
Sea pineapple	Halocynthia roretzi	Chordata
Sea butterfly	Clione spp.	Mollusca
Sea spider	Pantopoda	Arthropoda
Sea urchin	Strongylocentrotus spp.	Echinodermata
Sea slug	Aeolidina	Mollusca
Sea lily	Metacrinus rotundus	Echinodermata
Sea cucumber	Thelenota ananas	Echinodermata
Sea spider	Ammotheidae	Arthropoda
Sea moth	Pegasus volitans	Chordata
Sea pineapple	Pyura stolonifera	Chordata
Sea butterfly	Limacina spp.	Mollusca

-Features
Phylum	Level of Organisation	Symmetry	Coelom	Segmention	Digestive System	Circulatory System	Respiratory System	Distinctive Features
Porifera	Cellular	Various	Absent	Absent	Absent	Absent	Absent	Body with pores and canals in walls.
Coelenterata (Cnidaria)	Tissue	Radial	Absent	Absent	Incomplete	Absent	Absent	Cnidoblasts present.
Ctenophora	Tissue	Radial	Absent	Absent	Incomplete	Absent	Absent	Comb plates for locomotion.
Platyhelm- inthes	Organ & Organ – system	Bilateral	Absent	Absent	Incomplete	Absent	Absent	Flat body, suckers.
Aschelmin- thes	Organ – system	Bilateral	Pseudo-coelomate	Absent	Complete	Absent	Absent	Often wormshaped, elongated.
Annelida	Organ – system	Bilateral	Coelomate	Present	Complete	Present	Absent	Body segmentation like rings.
Arthropoda	Organ – system	Bilateral	Coelomate	Present	Complete	Present	Present	Exoskeleton of cuticle, jointed appendages.
Mollusca	Organ – system	Bilateral	Coelomate	Absent	Complete	Present	Present	External skeleton of shell usually present.
Echino- dermata	Organ- system	Radial	Coelomate	Absent	Complete	Present	Present	Water vascular system, radial symmetry.
Hemi- chordata	Organ- system	Bilateral	Coelomate	Absent	Complete	Present	Present	Worm-like with proboscis, collar and trunk.
Chordata	Organ- system	Bilateral	Coelomate	Present	Complete	Present	Present	Notochord, dorsal hollow nerve cord, gill slits with limbs or fins.