top of page

Guess the Invertebrate

From the Cover of the 25th Anniversary Issue of Invertebrate Biology

(download cover and editorial)

Below are marine invertebrates from 24 classes/subclasses from 14 phyla/subphyla.

How many can you identify to Phylum?  to Class?  to Family?

Roughly how big is each one?

Hover or tap on an image to view the answers.**

Marine Invertebrate Color Images

NAME:  Pelagic blue button (Porpita porpita; Cnidaria, Hydrozoa, Porpitidae)

SIZE:  2 cm

VIEW FULL-SIZED IMAGE

NAME:  Leopard sea anemones (Nemanthus sp.?; Cnidaria, Anthozoa, Nemanthidae)

SIZE:  1 cm

VIEW FULL-SIZED IMAGE

NAME:  Lancelet (Branchiostoma sp.; Chordata, Cephalochordata, Branchiostomatidae)

SIZE:  3 cm

VIEW FULL-SIZED IMAGE

NAME:  Inarticulate brachiopod (Brachiopoda, Linguliformea)

SIZE:  4 cm with peduncle

VIEW FULL-SIZED IMAGE

NAME:  Cumacean

(Eocuma sp.?; Arthropoda, Malacostraca, Peracarida, Cumacea, Bodotriidae)

SIZE:  0.7 cm

VIEW FULL-SIZED IMAGE

NAME:  Non-snapping alpheid shrimp (Coronalpheus natator; Arthropoda, Malacostraca, Decapoda, Caridea, Alpheidae)

SIZE:  2 cm

VIEW FULL-SIZED IMAGE

NAME:  Trochid snail (Calliostoma cf. javanicum; Mollusca, Gastropoda, Vetigastropoda, Calliostomatidae)

SIZE:  3 cm

VIEW FULL-SIZED IMAGE

NAME:  Ribbon worm

(Nemertea, Hoplonemertea, Monostilifera)

SIZE:  Extended length >5 cm

VIEW FULL-SIZED IMAGE

NAME:  Porcelain crab

(Petrolisthes donadio; Arthropoda, Malacostraca, Decapoda, Anomura, Porcellanidae)

SIZE:  1.5 cm carapace width

VIEW FULL-SIZED IMAGE

NAME:  Fire worm (Hermodice carunculate; Annelida, Errantia, Amphinomidae)

SIZE:  10 cm

VIEW FULL-SIZED IMAGE

NAME:  Hairy crab

(Pilumnus vespertilio; Arthropoda, Malacostraca, Decapoda, Brachyura, Pilumnidae)

SIZE:  3 cm

VIEW FULL-SIZED IMAGE

NAME:  Jewel-beetle amphipod (Thamneus cf. rostratus; Arthropoda, Malacostraca, Amphipoda, Hyperiidea, Brachyscelidae)

SIZE:  1 cm

VIEW FULL-SIZED IMAGE

NAME:  Doridoid sea slug (Halgerda wasinensis; Mollusca, Gastropoda, Heterobranchia, Discodorididae)

SIZE:  3 cm

VIEW FULL-SIZED IMAGE

NAME:  Feather duster worm (Branchiomma sp.; Annelida, Sedentaria, Sabellidae)

SIZE:  7 cm

VIEW FULL-SIZED IMAGE

NAME:  Acorn worm

(Saccoglossus bromophenolosus; Hemichordata, Enteropneusta, Harrimaniidae)

SIZE:  6 cm

VIEW FULL-SIZED IMAGE

NAME:  Planktonic juvenile of a tube-dwelling anemone

(Cnidaria; Anthozoa; Ceriantharia)

SIZE:  0.5 cm

VIEW FULL-SIZED IMAGE

NAME:  Polyclad flatworm (Pseudoceros bifurcus; Platyhelminthes, Rhabditophora, Polycladida, Pseudocerotidae)

SIZE:  3 cm

VIEW FULL-SIZED IMAGE

NAME:  Sea apple sea cucumber (Pseudocolochirus violaceus; Echinodermata, Holothuroidea, Cucumariidae)

SIZE:  15 cm

VIEW FULL-SIZED IMAGE

NAME:  Frog crab

(Raninoides benedicti; Arthropoda, Malacostraca, Decapoda, Brachyura, Raninidae)

SIZE:  5 cm

VIEW FULL-SIZED IMAGE

NAME:  Orange gum drop sea slug (Berthellina ilisima; Mollusca, Gastropoda, Heterobranchia, Pleurobranchida, Pleurobranchidae)

SIZE:  3 cm

VIEW FULL-SIZED IMAGE

NAME:  Segmented worm rolled in a spiral

(Nereis cf. riisei; Annelida, Polychaeta, Nereididae)

SIZE:  4 cm

VIEW FULL-SIZED IMAGE

NAME: Galeommatid clam (Scintilla sp.?; Mollusca, Bivalvia, Euheterodonta, Galeommatidae)

SIZE:  1 cm

VIEW FULL-SIZED IMAGE

NAME:  Electric brittle-star (Ophiothrix sp.; Echinodermata, Ophiuroidea, Ophiotrichidae)

SIZE:  Disc diam.1 cm

VIEW FULL-SIZED IMAGE

NAME:  Male ovigerous

sea spider (Arthropoda, Chelicerata, Pycnogonida)

SIZE:  <1 cm trunk length

VIEW FULL-SIZED IMAGE

NAME:  Deepwater peanut worm (“Sipuncula”)

SIZE:  4 cm

VIEW FULL-SIZED IMAGE

NAME:  Heart urchin

(Lovenia sp.; Echinodermata, Echinoidea, Loveniidae)

SIZE:  5 cm

VIEW FULL-SIZED IMAGE

NAME:  Anthurid isopod (Arthropoda, Malacostraca, Isopoda, Anthuridae)

SIZE:  1 cm

VIEW FULL-SIZED IMAGE

NAME:  Chilean mole crab,

face view (Emerita cf. analoga; Arthropoda, Malacostraca, Decapoda, Anomura, Hippidae)

SIZE:  2 cm

VIEW FULL-SIZED IMAGE

NAME:  Tropical sponge,

French Polynesia

(Porifera, Demospongiae)

SIZE:  15 cm

VIEW FULL-SIZED IMAGE

NAME:  Mantis shrimp,

face view (Squilla aculeata; Arthropoda, Malacostraca, Stomatopoda, Squillidae)

SIZE:  10 cm

VIEW FULL-SIZED IMAGE

NAME:  Boxer shrimp (Stenopus scutellatus; Arthropoda, Malacostraca, Decapoda, Stenopodidea, Stenopodidae)

SIZW:  4 cm

VIEW FULL-SIZED IMAGE

NAME:  Horseshoe crab (Tachypleus gigas; Arthropoda, Chelicerata, Merostomata, Limulidae)

SIZE:  20 cm

VIEW FULL-SIZED IMAGE

NAME:  Innkeeper worm (Ochetostoma sp.; Annelida, “Echiura”, Thalassematidae)

SIZE:  7 cm

VIEW FULL-SIZED IMAGE

These photos are from Dr. Arthur Anker's galleries of gorgeous invertebrate images:

Marine InvertebratesIconography for Invertebrate Zoology CourseScientific Photography.

Classification according to WoRMS (Jan. 2021, unless taxon name is in quotes).

Sizes are approximate (maximum dimensions unless noted otherwise).

Collage & web page by A. Richard Palmer (send errors or corrections here).

​

** Hover & tap functions work only on desktops, laptops or tablets, not mobile phones.

©2024 by American Microscopical Society.  Created with Wix.com

bottom of page