Seahorses can pair up for life with their male partners, but the females seem to forget about the male if they are separated for more than a few days.
A male and a female-lined seahorse (Hippocampus, erectus) near the Bahamas Shane Gross/naturepl.com
Sometimes male seahorses can be called nature's best fathers because they form close monogamous relationships with females and carry their pregnancy from the moment of fertilization until the time of birth. Female seahorses might see things differently. If the male seahorse is separated for even a few days, they may forget the long-term relationship they have with their female partner.
Hippocampus erectus, a line of seahorses (lined seahorses) is sexually monogamous and usually mat for life. They are not like other seahorses in that they do not mate for life.