The Secret Life of Seahorses n Though the

The Secret Life of Seahorses n “Though the seahorse in the Ocean, own no dear domestic cave; Yet he slumbers by the motion - Rocked by many a gentle wave. ” – Wordsworth. Song for the Wandering Jew 1827

Some interesting notes n n n Hippocampus stems from the Greek roots for ‘horse’ and ‘monster’ Earliest description is found in Aristotle c. 340 BC Historical references: – Talisman (Baltic) – Leprosey (India) – Hydrophobia (England) – Aphrodesiac (China) – Insanity Potion (Roman) – As a tonic for land horses (Greek)

and some ‘biological’ facts n n n Size range from 1. 5 cm to over 60 cm Longevity is estimated at 3 years Feed continuously but only on live food Exhibit physiological color change Have ‘tufted’ gills, independent rotational eyes, prehensile tail, produce sounds Brood size varies from 6 -20 to over 300

What’s so unusual ? n n n External brooding in a paternal pouch distinguishes seahorses and pipefishes. Females oviposit into the male pouch, where the eggs are fertilized and incubated to term. The pouch functions in 1) ion regulation, 2) gas exchange, and 3) materials transfer. Embryos hatch precociously, yet remain enveloped in male pouch tissue for further development. Surfaces develop on the brood pouch and on the embryo to facilitate paternal-embryonic uptake.

Who’s who of the paternal brooders Family: Solenostomidae (Ghost Pipefishes) – Eggs brooded within a female pelvis fin sac – One genus, 3 -5 species n Family: Syngnathidae (Pipefishes & Seahorse) – Eggs brooded or abdomen of the male, or within a broodpouch of the male. – 34 genera of pipefishes – one genus of seahorse n

Ghost Pipefish

Pipefishes

here be dragons !

The “seapipe”

The seahorse male broodpouch

Gestation within the pouch

Embryo envelopment & gestation

Is the broodpouch a ‘placenta’ ?

Calcium sequestered for the emerging dermal skeleton

Transferring iron from the male pouch fluid

Parturition in the dwarf seahorse, Hippocampus zosterae

Gastrulation truly is the most important part of your life. Paraphrased after L. Wolpart