Invertebrate
37 invertebrate organisms and their business parallels
Antarctic Krill
Antarctic krill represent the inverse of blue whale strategy and simultaneously the foundation of it: tiny (2-inch), short-lived (5-7 years), massivel...
Bdelloid Rotifer
Bdelloid rotifers share the tardigrade's seemingly impossible survival capabilities: they can desiccate completely, remain in suspended animation for...
Brain Coral
Brain coral colonies are clonal organisms comparable to aspen groves - thousands of genetically identical polyps building a shared calcium carbonate s...
Bryozoan
Bryozoans are colonial animals where thousands of genetically identical individuals (zooids) combine to form structures resembling moss, lace, or cora...
C. elegans Nematode Worm
The C. elegans nematode worm is the chapter's central organism and one of biology's most important model organisms for aging research. This tiny trans...
Caenorhabditis elegans
A nematode worm with exactly 302 neurons whose complete connectome (neural wiring diagram) was first mapped in 1986 after a 15-year effort. C. elegans...
Caenorhabditis elegans
Caenorhabditis elegans validated in a multicellular animal what yeast research suggested: caloric restriction extends lifespan through conserved molec...
California Spiny Lobster
Spiny lobsters are crustacean keystone predators that control urchin populations in areas where sea otters are absent. Before otter populations crashe...
Cephalopods
Two-thirds of an octopus's neurons are in its arms. The central brain makes decisions; the arms execute—and remember—independently. This is distribute...
Colossal Squid
Colossal squid achieve blue whale-scale body mass (1,000+ pounds, 40+ feet) through the inverse metabolic strategy: cold-blooded physiology, short lif...
Comb Jelly
Comb jellies are not true jellyfish but a separate phylum that independently evolved similar body forms. They demonstrate remarkable regeneration—some...
Coral
Reef-building corals are the ultimate ecosystem engineers: their accumulated skeletons create the physical structure of entire ecosystems. Coral reefs...
Crown-of-Thorns Starfish
Crown-of-thorns starfish have no brain whatsoever. Their nervous system is a ring connecting radial nerves in each arm - pure distribution without cen...
Cryptobiotic Nematode
Nematode worms represent one of the most successful animal body plans, found in virtually every environment from Antarctic ice to deep ocean sediments...
Drosophila melanogaster
Drosophila melanogaster—the common fruit fly—extended aging research from worms to complex organisms with differentiated tissues, organs, and behavior...
Dugesia
Dugesia flatworms share the hydra's remarkable regeneration—cut into pieces, each fragment regenerates into a complete organism. But Dugesia adds a fa...
Earthworm
Charles Darwin spent the final years of his life studying earthworms, and what he found astonished him: approximately 53,000 worms per acre, moving 10...
Earthworms
Earthworms are key decomposers that mechanically break apart dead plant and animal tissues, reducing particle sizes and increasing surface area access...
Giant Barrel Sponge
Giant barrel sponges may live over 2,000 years—longer than almost any animal—though their simple structure makes aging estimates difficult. These anci...
Giant Tube Worm
Giant tube worms cluster around deep-sea hydrothermal vents, growing 6 feet long in tubes of their own secretion. They have no mouth, gut, or anus - t...
Loricifera
Loriciferans are microscopic animals discovered in 2010 to live permanently without oxygen in the deep Mediterranean's anoxic sediments. Before this d...
Marine Planktonic Larvae
Marine organisms with planktonic larvae that drift long distances on ocean currents experience high gene flow, homogenizing populations across vast ge...
Marine Sponge
Sponges are among Earth's oldest animals, with fossils dating back 890 million years. Before coral reefs existed, sponges built the seafloor's three-d...
Ochre Sea Star
The ochre sea star is where keystone species theory began. In 1966, ecologist Robert Paine removed sea stars from a stretch of Washington coastline an...
Pisaster ochraceus
The ochre sea star is the original keystone species, studied by Robert Paine in his foundational 1963 experiment. This starfish represented less than...
Planarian Flatworm
Planarian flatworms represent regeneration's extreme: cut one into 279 pieces, and each piece can regenerate into a complete worm with head, tail, bra...
Pompeii Worm
The Pompeii worm lives in one of Earth's most hostile environments: hydrothermal vent chimneys where temperatures reach 80°C (176°F)—the upper limit f...
Purple Sea Urchin
Purple sea urchins have become the poster species for keystone predation collapse in California. Following the sunflower sea star die-off and continue...
Red Sea Urchin
Red sea urchins are the prey that sea otter keystone predation controls. Without otters, urchin populations explode and devour kelp forests, creating...
Sea Cucumber
Sea cucumbers defend themselves through evisceration - literally expelling their internal organs at threats. When stressed, they eject sticky, sometim...
Sea Star
Sea stars can regenerate lost arms, and some species can regrow an entire body from a single detached arm—provided that arm contains part of the centr...
Sea Urchin
Sea urchins didn't choose to become ecosystem destroyers - the system chose it for them. When sea otter populations collapsed in the 19th century, urc...
Sunflower Sea Star
Sunflower sea stars were the secondary urchin predators in kelp forest ecosystems—not as effective as sea otters but providing backup control. With 20...
Sunflower Starfish
Sunflower starfish are the largest sea stars in the world, reaching 3 feet across with up to 24 arms. They're voracious predators of sea urchins, prov...
Tapeworm
Tapeworms represent classic parasitism - extracting nutrients from their host's intestines while the host suffers malnutrition. Unlike mutualism where...
Termite
Mound-building termites are the most prolific ecosystem engineers on Earth, constructing structures that can exceed 30 feet in height and persist for...
Tube Sponge
Tube sponges can be forced through a fine mesh, separating into individual cells, and will reaggregate into a functional sponge. This extreme regenera...