Reproductive Preferences
Some populations of cuttlefish in the northern Atlantic prefer colder seasons to spawn in, contradictory to a lot of other marine species that migrate towards warmer pockets of the ocean to breed. It is important to know that as temperatures rose seasonally, clutch size decreased, which indicates seasonal spawning patterns.
There are several populations of cuttlefish that choose to breed in the Cies islands of northwestern Spain. S. officinalis was found to lay large clutches at preferred depths of 8 - 13 meters, and temperatures of 15°C. (After calculations, hydrostatic pressure would be maximally at around 2.286 atm at a depth of 13m)
(Table 1)
Substrate type was also a determinant factor in the clutch size of cuttlefish, as in Table 3. Interestingly, the largest counts of eggs spawn were seen to be incubating on a species of coral called
Leptogorgia sarmentosa (picture of coral here), with around 60 eggs.
There was a drastic differential in clutch size of other marine substrates.
Cystoseira is a type of algae that grows in this region, and it was the
location of the next highest clutch size of around 15 eggs. A species
of sea oak, called Halidrys siliquosa, and red seaweed called Halymenia
latifolia were also observed to have significantly smaller clutch sizes.
This shows us that there are specific marine
algae and coral structures that cuttlefish prefer to spawn on, and clutch
size increases in environments containing Leptogorgia sarmentosa.
(Leptogorgia sarmentosa)
(Halidrys siliquosa)
(Halymenia latifolia)
Reproductive Behavior
Cuttlefish are known for their colorful array of patterns and camouflage. They use their abilities to sense light to contrast themselves against their native environments. To find a mate, it is essential for a male cuttlefish to stand out amongst the competition to ensure his next generation are successful and fit to survive in the ocean depths.
To study these behaviors that drive the mating rituals of cuttlefish, scientists studied a particularly striking species called Metasepia pfefferi.
The coloration and exuberant texture has consistently
caught the attention of photographers. This species of
cuttlefish are commonly seen in newspapers and journals,
yet their behavior is wildly understudied.
​
From this study, a sample size of 400 Metasepia pfefferi cuttlefish was studied via submerged videography equipment. Sexual dimorphism was noted in several ways - primarily, in the size difference between males and females. Females were seen to be larger in body mass as compared to males, and pattern vibrancy and frequency.
Males approach females from a distance, signaling interest through a vibrant and beautiful display of their color-changing pigmented skin. Even though particular sequences of this courtship dance varied, males were always seen to give waving and kissing motions towards the female. While males may remain in their courtship ritual for longer periods of time, females remain in an ambiguous state, without reflecting the same colorful patterns back to the male.
Females that get approached by males interested in mating while they are preoccupied with hunting or grazing tend to be apathetic towards the male’s advances, or simply ignore them altogether.
Male Competition
Males also may compete simultaneously with other males in front of a female for the chance to mate. No physical interaction is involved between competing males, however, these male cuttlefish would display a solid white pattern on the side of their body that faced the other male. Reasons as to why this phenomenon exists are unknown, however, this behavior might be another form of competition. Total courtship rituals vary in time, ranging from 6 minutes to 80 minutes long.
Another mechanism of mate selection is mate guarding. Once a male cuttlefish has successfully mated with a female, some males guard that female when another male enters the vicinity. In some instances, those guarding males were seen to ward off competing males.