About cephalopods
Cephalopods (squids, octopuses,
cuttlefish and nautiluses) compose
a well-defined class of Mollusca.
These attractive invertebrates have evolved complex visual and neural systems, resulting in intriguingly versatile behaviors and cognitive abilities. They have diverse life histories and occupy a wide range of habitats.
Cephalopods are recognized by their unique anatomical and biological features that are not shared with others mollusks.
Their large and sophisticated eyes allow them to learn by experience and perform high-order cognitive tasks. Their skin displays a remarkable system of pigmented cells called chromatophores that allow impressive changes of their coloration, pattern, and texture in fractions of a second (except the Nautilus). Their arms and tentacles bear muscular suckers that designed to catch and hold prey of a wide variety of sizes.
Many groups use a unique dual-mode system for locomotion, combining pulsed jetting and fin-flapping that drive high swimming speeds.
Image from
OLAW | Cephalopods in Research
"Cephalopod life cycle patterns. All known cephalopod life cycles can be distilled into four major categories: (A) Life cycles with a Paralarval phase. These species are either Merobenthic (brown circles) or Holopelagic (blue-green circles). E, Embryonic; P, Paralarval; J, Juvenile; S, Subadult; A, Adult Phases. Merobenthic species are primarily found on the shelf, and are characterized by having benthic eggs and planktonic paralarvae (P), and JSA phases that live either near bottom or on bottom. Holopelagic species live all phases of their life cycle in the water column, either entirely within a depth horizon, or moving between multiple depth horizons. (B) Life cycles without a Paralarval phase. Species without a Paralarval phase are either Meropelagic (brown circles) or Holobenthic (black circles). Meropelagic life cycles are characterized by having benthic eggs, and JSA that live near-bottom or off-bottom and into the water column. In some of these species, the JSA are highly mobile and may move extensively in the water column as suggested by the dashed arrows. Holobenthic species live all phases of their life cycle on bottom"
These rapidly growing animals have relatively short life cycles and die after a single reproduction period. The diversity of paralarval and juvenile forms is evidence of their rich evolutionary history. Early-life stages are also capable of a wide array of behavioral and ecological adaptations
Cephalopods have a high production-to-biomass-ratio, making them important components in the trophic structure of marine ecosystems and object of valuable capture fisheries.
These remarkable animals are noticeably sensitive to environmental variations; this is particularly true of their early-life stages. This has become of special concern in a time of changing ocean climate and, by itself, warrants research that adds to our knowledge of these fascinating animals.
