15 Majestic Yellow Sea Slug Varieties, 2024

In another article, we discussed about 15 different varieties of sea slugs with red color. Today we will talk about the other 15 varieties of slugs, which have yellow coloration in their body. The yellow color provides an excellent elegance to this shell-less creature.

15 Majestic Yellow Sea Slug Varieties

1) Phyllidia ocellata

Phyllidia ocellata
Phyllidia ocellata | Credit: Sébastien Vasquez (commons.wikimedia) CC BY-SA 4.0
Scientific Name Phyllidia ocellata
Size Maximum of 35 mm.
Geographic Location Indo-West Pacific Ocean.
Identification Yellow dorsal side with symmetrical black rings. At the center of the black rings, there are large whitish tubules and small tubules along the mantle edge.

Their prominent coloration as well as the large white tubules acts as a warning signal towards predators. It is often confused with other members of its genus, and considerable variations occur between members of the same species sometimes.

The juveniles resemble almost the adults in external features.


2) Phyllidia flava

Scientific Name Phyllidia flava
Size Between 4.5 cm to 5 cm
Geographic Location Mainly found in the Mediterranean Sea.
Identification Yellow dorsal body, a bit transparent. White-spotted tubercules are present.

These slug species have a similar color pattern to P. ocellata although it doesn’t have the characteristic dark circles. The rhinophores are yellowish-orange.

These slugs feed on different sponge species, although their favorite prey is Acanthella acuta sponge. They are mainly found at a depth of 20-25 meters.


3) Sea Bunny

Scientific Name Jorunna parva
Size Maximum of 1 cm.
Geographic Location Philippines, New Guniea, Tanzaia.
Identification Yellow body, with dark-brown papillae distributed throughout. Black rhinophores.

The reason that these slug species are known as sea bunnies is due to their small appearance and especially their rhinophores, which resemble the ears of rabbits. The papillae-covered body is looks provides a furr-like appearance just like the furry body of a rabbit.

Other variants of this species include green and especially white. The sea bunny slugs were first discovered in the Kii Province of China.

Being cute is their specialty!


4) Banana Nudibranch

Banana Nudibranch
Banana Nudibranch | Credit: Nhobgood (commons.wikimedia) CC BY-SA 4.0
Scientific Name Notodoris minor
Size Grows up to 14 cm.
Geographic Location Generally found in Indo-West Pacific Coasts.
Identification An elongated body with a yellow color and the entire body is covered with transverse black lines.

The coloring pattern of these slugs resembles that of a banana, hence the name. The body has tiny spicules. Apart from the body, the gills and rhinophores tend to be yellow, but in some species, it might be black.

These slugs feed on Pericharax heterographis sponges and their distribution depends on where the sponges are found more abundantly. Unlike other slugs, their gills are hidden by three large lobes.


5) Gem Sea Slug

Scientific Name Goniobranchus geminus
Size  5 cm on average.
Geographic Location Coasts of the Indian Ocean such as from Kenya to Sri Lanka and the Red Sea.
Identification Yellow body with purple spots lined with a white border. Rhinophores are yellow.

Like many colorful nudibranchs, these slugs are also toxic and their special color pattern marks them toxic in the eyes of predators.

The border of the mantle has a white color, then a purple-grayish border then again a white margin which is followed by a yellow border. The white gills have a dark or purplish-black coloration.

Their underside is also very similar to the upper side. These slugs have a very attractive look which mesmerised a lot of divers when they spot this slug species underwater.


6) Regal sea goddess nudibranch

Scientific Name Felimare picta
Size Up to 13 cm.
Geographic Location Mainly found in the Mediterranean Sea, Gulf of Mexico, and the European waters.
Identification Dark blue to almost black color, and with numerous yellow markings.

The color pattern changes as the animal grows in size. The small animals have yellow bands running in the middle of the back. As the animal grows in size and age, more lines appear and they become fragmented. Along with stripes, more and more yellow spots start to appear.

These slugs feed on toxic sponges of the genus Dysideidae. However, the toxin can not harm them instead they can store it in their body for an indefinite time to use it to avoid predation.


7) Willey’s Halgerda

Scientific Name Halgerda willeyi
Size Maximum of 50 mm to 70 mm.
Geographic Location Indo-West Pacific Waters, Red Sea.
Identification Multiple interconnected ridges with yellow coloration. Chocolate-brown lines are present between the grooves of the ridges.

These slugs are one of the largest specimens from the Halgerda genus. They are rarely seen and the ridge-like structures give them a rocky appearance.

Overall body color can range from translucent white to light brown. The brown lines radiate from the ridges towards the mantle in a radiating fashion. The liens also extend covering the gills as well.


8) White-Spotted Sea Goddess

Scientific Name Doriopsilla albopunctata
Size Up to 60 mm.
Geographic Location Coasts of California and Mexico.
Identification Generally Bright Yellow (orange or brown in some species), with orangish-yellow rhinophores on the top.

It is not exactly known why someone decided to call them “Sea Goddess”, it might be due to their bright appearance and white dots present on the upper body-which resemble that of a “Galaxy”. The gills are present on the back in a rosette-like fashion and they are white.

The eggs are spiral-ribbon-like and attach to the edges of rocks. These are generally yellow to off-white.


9) Sea Lemon

Scientific Name Peltodoris nobilis
Size Extremely large, about 200 mm. (8 inches)
Geographic Location East coast of the Pacific Ocean, ranging from Alaska to Baja California.
Identification The body is covered with numerous yellow tubercules, and there are dark spots between the tubercules. The spots are never inside the tubercules.

These slug species are called sea lemons because when they are held too tightly, they radiate smells similar to that of a citrus fruit! They are also known as “Noble Dorid” slugs.

They are huge compared to other slugs and can be similar to an average-sized phone. The gills are rosette-shaped and with white borders. They mainly feed on Mycale adhaerens Sponge species.


10) Yellow Noumea

Scientific Name Diversidoris flava
Size Maximum 2 inches or less.
Geographic Location Indo-West Pacific coasts, Australia. Originally it was first discovered in East Africa.
Identification Yellow mantle body and prominent red margin along the mantle edge.

The mantle has two semi-permeable folds in the middle of the body. Apart from the body, the rhinophores and gills are also yellow.

Most of the members in this genus have the same body coloration, in some slugs, the mantle edge can be a different color so identifying a particular species sometimes becomes confusing.


11) Cadlinella hirsuta

Scientific Name Cadlinella ornatissima
Size Between 20 mm to a maximum of 40 mm.
Geographic Location Tropical Coasts of Indo-Wes Pacific.
Identification Yellow body covered with Tubercules, which are white in the basal end and have purple spots on the tip.

The Rhinophores and gills are long in this species. Rhinophores are prominently white and feather-like. The body has characteristics of flask-shaped, single-celled, and compound mantle glands present on the mantle edge.


12) Ardeadoris rubroannulata

Scientific Name Ardeadoris rubroannulata
Size Very Large, Up tp 90 mm.
Geographic Location Limited distribution, found only in New Caledonia, East Coast of Sub-tropical Australia, Great Barrier Reef.
Identification Golden Yellow mantle color and the mantle margin has combinations of golden, red, and white colors.

These large slugs have mottled mantle folds on the lateral sides. The rhinophores are orangish-red with a white base.

The extremity of the mantle edge is yellow-colored, followed by the red marginal lines, and white is followed after that both on the dorsal and ventral sides of the body. The foot is pure white with the same marginal patterns as described.

The gills are long and translucent with red stripes and white tips. These slugs release unpleasant and toxic fluids when they feel threatened.


13) Verco’s Nudibranch

Scientific Name Tambja verconis
Size Up to 12 centimeters.
Geographic Location It is found generally in Southern Australia and New Zealand.
Identification The body is yellow colored. The mantle margin has an interrupted pattern of blue color and blue pustules present on the upper body.

These slugs are Sublittoral, meaning they usually grow near the seashore. They are usually found at a depth of 2 meters to 40 meters deep. Their favorite meal is bushy Bryozoans such as Bugula dentata.

The gills are large with blue coloration. Rhinphores are dark blue. Due to their striking color pattern, they are easily recognizable.


14) Yellow-plumed sea slug

Scientific Name Berthella plumula
Size Around 60 mm.
Geographic Location Northeastern Atlantic, Mediterranea Sea, English Channel.
Identification Pale-yellow mantle color without any tubercules in the upper body. Net-like markings are present on the

The mantle covers the entire body except the rhinophores, foot, and the oral veil. An interesting thing about these slugs is that they have an internal shell unlike other shell-less mollusks, and it is covered with the smooth mantle itself.

These slugs have central transparent patches in the upper body. This and the reticulations in the body give them a perfect camouflage advantage. These slugs have acid glands from which they release sulphuric acid when they are attacked or feel irritated.


15) Verconia laboutei

Scientific Name Verconia laboutei
Size Usually between 11 mm to 15 mm.
Geographic Location Generally in tropical West Pacific coasts.
Identification Bright Yellow body with wine-red colored rhinophores and gills.

Not much information is there regarding these slug species. Their wine-red gills have lamellae with outer and inner ridges. The mantle has some reticulate patterns.


Conclusion

The yellow-colored sea slugs are vibrant looking and oftentimes divers spot them. But they can easily blend themselves in yellow or orangish sponge colonies to hide from predators.


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