Egg Case Identification Guide

Diagram of an egg case

Parts of an egg case

Egg cases washed up on the shore can often be dry and brittle. Before identifying your egg case, soak it in water to rehydrate it and allow it to expand to its original size. The approximate lengths below are for rehydrated egg cases.

Don't forget to record your egg case finds after you have identified them!

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Download your own Egg Case ID Guide below or scroll down to discover what egg case you've found!

Eggcase of blackmouth catshark

Blackmouth Catshark

Scientific name: Galeus melastomus

  • Capsule length ~5cm (ranges from 3–7cm)

  • Small upper horns 

Eggcase of smallspotted catshark

Smallspotted Catshark

Scientific name: Scyliorhinus canicula

  • Small egg case

  • Capsule length 5 - 7cm

  • Curly tendrils at each corner

  • Can be many colours (don't use colour to ID)

Eggcase of a bullhuss

Bullhuss / Nursehound / Greaterspotted Catshark

Scientific name: Scyliorhinus stellaris

  • Moderately large egg case

  • Capsule length 8 - 10cm

  • Thick walls run the length of the capsule joining the two sides

  • Thick curly tendrils extend from each corner

Egg case of spotted ray

Spotted Ray

Scientific name: Raja montagui

  • Smaller egg case

  • Capsule length 5 - 6cm

  • Often confused with the Undulate Ray egg case but has a more common distribution

Eggcase of cuckoo ray

Cuckoo Ray

Scientific name: Leucoraja naevus

  • Small and rounded egg case
  • Capsule length 5 - 6cm
  • Upper horns are very long and curved (if intact!)


Egg case of thornback ray

Thornback Ray

Scientific name: Raja clavata

  • Moderate size egg case
  • Capsule length 6 - 7cm
  • Can be square or rectangular
  • Well-formed keels and horns
Egg case of small eyed ray

Small-Eyed Ray

Scientific name: Raja microocellata

  • Capsule tapered from top to bottom
  • Capsule length 7 - 8cm


Egg case of undulate ray

Undulate Ray

Scientific name: Raja undulata

  • Moderately large egg case
  • Capsule length 7 - 8cm
  • Small fringe may be present along the margin
  • Additional fibers often present
Egg case of a blonde ray

Blonde Ray

Scientific name: Raja brachyura

  • Large egg case

  • Capsule length 10 - 12cm

  • Horns often broken and confused with Common Skate

Egg case of flapper skate

Common Skate / Flapper Skate

Scientific name: Dipturus batis / Dipturus intermedia

  • Very large egg case
  • Capsule length 15 - 20cm
  • Covered in dense, bark-like substance