egg guarding | The Marine Detective

Posts tagged ‘egg guarding’

Fishy Fathers

There’s a whole lotta fish procreation going on in the NE Pacific Ocean right now. This might be a surprise to those who think mating is more of a spring-fling-kinda-thing.

It may be a further surprise that, for many marine fish species here, the males are the protectors of the next generation. The females leave after laying the eggs and the males remain, guarding the fertilized eggs from predators and often also fanning the eggs to ensure they are well aerated.

For a lot of these fish species, the male chooses the nesting site and entices multiple females to lay eggs there so that he can fertilize them. He then has the work of guarding these multiple egg masses and may need to be on the alert for sneak fertilization attempts by other males.

For species with nests of multiple egg masses, you can often tell how many females have laid eggs there because individual females have different coloured eggs. Therefore, the colour of fish eggs is not a good characteristic to determine the species that laid them. Instead, do a quick scan, chances are a piscine papa is somewhere near the eggs, staring at you.

Through the photos below, meet some of these fabulous fish fathers. No deadbeat dads here!

[Note that this is in no way a comprehensive list of NE Pacific Ocean fish species in which the males guard the eggs.]

Whitespotted Greenling

The encounter documented below shows how my dive buddy and I recently had a whitespotted greenling come after us, so intent was he on protecting his egg masses. I was very slow in cluing in that this was why he was swimming around us and deserved getting a little nip in the head. Notice how small he is relative to us and yet how this did not deter him in trying to get rid of us.

Male Whitespotted Greenling shortly after he nipped my big head in his intensity to guard his egg masses. ©Jackie Hildering

Dive buddy Jacqui Engel pointing at the male White-Spotted Greenling before we clued in and got out of his territory with eggs. Image shows small the fish is compared to us and how big his drive to protect the egg masses that he would come after us. © 2013 Jackie Hildering

Dive buddy Jacqui Engel pointing at the male Whitespotted Greenling before I clued in and got out of his territory with eggs. Image shows how small the fish is compared to us and how big his drive to protect the egg masses must be that he would pursue us like he did. ©Jackie Hildering

Male White-Spotted Greenling intensely guarding eggs. © 2013 Jackie Hildering

Here he is intensely guarding eggs. ©Jackie Hildering

Whitespotted Greenling (Hexagrammos stelleri)

Maximum recorded size: 48 cm
My observations of egg guarding on NE Vancouver Island: September to December

Kelp Greenling

Most often Kelp Greenling eggs are in the empty shells of giant barnacles as shown below. Although they are a bigger member of the Greenling family, male Kelp Greenlings do not appear to protect their eggs quite as vigorously as Whitespotted Greenlings. They appear to have a really long breeding season in our area.

Male Kelp Greenling. ©Jackie Hildering

Eggs the male Kelp Greenling was guarding. Most often in giant barnacle tests (shells) like this. © 2013 Jackie Hildering

These are the eggs that the male Kelp Greenling in the above image was guarding. The eggs are most often laid in giant barnacle tests (shells) like this. ©Jackie Hildering

Kelp Greenling (Hexagrammos decagrammus)

Maximum recorded size: 61 cm
My observations of egg guarding on NE Vancouver Island: October to March
Below, slideshow of courting

Red Irish Lord

Oh Red Irish Lords how I love thee. There is no better ambassador for how colourful life is in these waters since they are brilliant shades, yet astoundingly camouflaged. Red Irish Lords are often easier to find when guarding their eggs since these are less camouflaged. They most often egg guard with their heads positioned right atop the eggs, remaining absolutely motionless. It is commonly believed that the fathers guard the eggs but apparently it is more often the mothers but that the parents may take turns. Source: DeMartini and Sikkel 2006: ” Red Irish Lord exhibits primarily maternal and facultatively biparental guarding of the spawn.”

Red Irish Lord guarding an egg mass – note the very different coloured eggs in the following images. ©Jackie Hildering

Male Red Irish Lord guarding egg mass. © 2013 Jackie Hildering

Red Irish Lord guarding egg mass. ©Jackie Hildering

Another Red Irish Lord guarding egg mass. Note the variation in the colour of the fish too. More photos showing the diversity of colour at this link. ©Jackie Hildering

Red Irish Lord (Hemilepidotus hemilepidotus)

Maximum recorded size: 51 cm
My observations of egg guarding on NE Vancouver Island: December to May
Previous TMD blog item on the species: In the Eye of the Lord (the Red Irish Lord That Is!)

Buffalo Sculpin

There are Buffalo Sculpin males guarding eggs at this time of year too but more mating appears to be happen in April and May. Usually, Buffalo Sculpins are even harder to spot than their Red Irish Lord cousins but the variably coloured, bright egg masses give away their location. They too have a strategy of staying right atop the eggs and remaining motionless when faced with annoying human divers.

Male Buffalo Sculpin guarding two egg masses – each from different females. ©Jackie Hildering

Male Buffalo Sculpin guarding egg mass. © 2013 Jackie Hildering

Male Buffalo Sculpin guarding egg mass. ©Jackie Hildering

Buffalo Sculpin (Enophrys bison)

Maximum recorded size: 37 cm
My observations of egg guarding on NE Vancouver Island: January to May
Previous TMD blog item on the species: Buffalos Mating Underwater

Lingcod

Soon we will be participating in the Vancouver Aquarium’s annual Lingcod Egg Mass Count. Armed with an underwater slate, we will join divers along the Coast in helping determine the health of lingcod populations by looking at the number and size of the egg masses and if they are being guarded by males. And oh what fastidious fathers lingcod males are! The dedication to protecting the egg masses does vary from male to male but, generally, they do not leave their watch until the eggs hatch which can be more than 24 days. They could be guarding masses from multiple females separated by more than 7 m, and if laid by a female 5 years old and older, the egg masses can be the size of a watermelon and weigh up to 14 kg! That’s a lot to protect! (As is also the case for many rockfish, the older the female lingcod, the more eggs she lays). My best lingcod story is that I was marking down “unguarded” on my slate only to have it knocked out of my hands by the male that was very much guarding the egg mass I had been observing! Lots more info on this species at my blog item Lingcod – Fastidious Fanged Fathers.

Lingcod male guarding egg mass. Photo is a bit fuzzy but the battle wound reveals the perils of egg guarding and/or competition for females. ©Jackie Hildering

Lingcod male guarding egg mass (with a couple of shrimp on his back). ©Jackie Hildering

Lingcod (Ophiodon elongatus)

Maximum recorded size: 152 cm
My observations of egg guarding on NE Vancouver Island: January to April (Vancouver Aquarium’s Egg Mass Survey is from early February to the beginning of April).
Previous TMD blog item on the species: Lingcod – Fastidious Fanged Fathers

Wolf-Eel

Here’s a case where it is not just the male that guards the eggs. Mr. and Mrs. Wolf-Eel take turns wrapping their long tails around the large egg mass. I hope to one day have the opportunity to get a better image than this but, as a strategy for survival, the egg mass is often deep within the wolf eel couple’s den. Lots more information on this remarkable species at my previous blog item Wolf-Eel – No Ugly Fish!

Mr. and Mrs. Wolf-Eel sharing duty in taking care of the egg mass. Female on left and male on right. ©Jackie Hildering

Wolf-Eel (Anarrhichthys ocellatus)

Maximum recorded size: 2.4 m
My observations of egg guarding on NE Vancouver Island: October to January
Previous TMD blog item on the species: Wolf-Eel – No Ugly Fish!

Cabezon

I’ve only once been lucky enough to find a male of this huge sculpin species guarding eggs. They can apparently be very aggressive guarders but this very successful male (he was guarding the eggs of several females) was very tolerant of my presence. They have been documented to mate throughout the year. My one encounter with a male cabezon guarding eggs was in May.

Male Cabezon guarding egg masses from multiple females (egg masses different colours). ©Jackie Hildering

Cabezon (Scorpaenichthys marmoratus)

Maximum recorded size: 99 cm

Painted Greenling

In all these years of diving, I have yet to find a male Painted Greening guarding eggs so that I know for sure the eggs are from this species. Yet something else to be on the lookout for!

Painted Greenling. ©Jackie Hildering

Painted Greenling (Oxylebius pictus)

Maximum recorded size: 25 cm

Grunt Sculpin

And, the stuff of dreams . . . to one day chance upon a male grunt sculpin while he is releasing the hatching eggs from . . . his mouth! For more on that, see my previous blog item Grunt Sculpin – Little Fish, BIG Attitude. The females apparently also do take on shifts in taking care of the eggs.

Grunt Sculpin. Most often found in empty barnacle tests (not cups!) ©Jackie Hildering

Grant Sculpin (Rhamphocottus richardsonii)

Maximum recorded size: 8.9 cm
My observations of egg guarding on NE Vancouver Island:
Previous TMD blog item on the species: Grunt Sculpin – Little Fish, BIG Attitude

You need not be a diver to see the eggs of the following two species.
While carefully lifting up rocks in the intertidal during the Spring, you might
come across these egg masses and possibly even the male guarding them.

Scalyhead Sculpin

I have never seen scalyhead sculpin eggs while diving, likely because they are hidden away and because they are much smaller. The image of the eggs below was taken during a beach walk where students ensured they put the rock back as best they could to reduce the chances of the eggs drying out. Notice the different colours of the looney-sized egg masses? The eggs in this nest are from at least 4 females.

Very interesting in this species is that fertilization is internal.

Male Scalyhead Sculpin in a giant barnacle test. © 2013 Jackie Hildering

Male Scalyhead Sculpin in a giant barnacle test. ©Jackie Hildering

Egg masses from at least 4 different female scalyhead sculpins (each female's eggs have a different colour). © 2013 Jackie Hildering

Photo taken while on a beach walk. Egg masses found under a rock and they are from at least 4 different females (each female’s eggs have a different colour). ©Jackie Hildering

Scalyhead Sculpin (Artedius harringtoni)

Max size: 10 cm
My observations of egg guarding on NE Vancouver Island: Spring.
One study showed that the eggs hatched after 11 and 15 days. This study also documented courtship where the males rolled their heads in a circle and flared their orange branchiostegal membranes (on the underside of their throat) which apparently are only orange during mating season. Females were seen to have no response or to snap their heads horizontally in rapid succession, sometimes also quivering. During breeding season the males are also reported to have red-brown spots inside their mouth and a brown anal fin with small yellowish-white spots. (Source: Ragland, H., & Fischer, E. (1987). Internal Fertilization and Male Parental Care in the Scalyhead Sculpin, Artedius harringtoni. Copeia, 1987(4), 1059-1062. doi:10.2307/1445578)
Previous TMD blog item on the species: Who’s Your Daddy

Black Prickleback

If you find an ice cream scoop mound like this, you have likely found the eggs of the black prickleback and the guarding male is likely very near. When taking students on beach walks, I emphasize the importance of not displacing animals by using this species as an example. Fish like the black prickleback are adapted to being able to wait out the tide in very little water and if the well-intentioned pick up the fish to put him in deeper water, they could be moving papa away from the eggs he was guarding.

Male Black Prickleback guarding egg mass in a tide pool. ©Jackie Hildering

Black Prickleback (Xiphister atropurpureus)

Max size: 32.7 cm
Records of egg guarding on NE Vancouver Island: Spring

Sources:

Lamb, Andy; Coastal Fishes of the Pacific Northwest
Love, Milton; Certainly More Than You Want to Know About the Fishes of the Pacific Coast

Grunt Sculpin – Little Fish, BIG Attitude!

Meet the fish that so often has people exclaiming “It lives HERE?!”

Yep, the tiny Grunt Sculpin is a powerful ambassador for raising awareness about the depth of biodiversity hidden in the cold, dark, rich waters of the north east Pacific.

We are programmed to associate warm waters with exotic-looking fish species but read below for the Grunt Sculpin’s astounding adaptations and masterful mimicry.

The species reaches only a maximum of 9 cm.

It is adapted to look like a Giant Acorn Barnacle (Balanus nubilis)! When facing outward, its pointy nose looks like a closed Giant Acorn Barnacle and when the fish turns around, its tail looks like the foot of the barnacle that rakes in plankton.

*Closed Giant Acorn Barnacles. See how similar this is to the nose of a Grunt Sculpin?*

*Foot of a Giant Acorn Barnacle. The tail of a Grunt Sculpin looks so much like this!*

This little fish has giant attitude. When not hidden away in a barnacle (or a cup, see photo), it can be highly territorial, hopping around on its pectoral fins in a strutting, jerky fashion. A lot of literature reports that the Grunt Sculpin is an “awkward swimmer” but I solidly disagree. I once saw one flash away with lightning speed back to its hiding place. Yes, I was being an annoying photographer.

*If you can’t find an empty barnacle shell. A cup will apparently do!*

Ah and you probably think the males are the master strutters? Ha! The female is as fierce as can be. Reportedly, she will chase a male into a crack, an empty barnacle shell, or another place of no escape and guard him there until she is ready to lay her eggs. When she has laid them, the male is released to do his duty.

She watches him to ensure he fertilizes the eggs (up to 150 at a time) and then, according to some sources – she saunters off leaving the male to care for the eggs but may return once in a while to take on a shift. (Source: Aquarium of the Pacific.

*Very young Grunt Sculpin. The Red-Gilled Nudibranch in the upper part of the image is only about 2 cm*

From Casey Cook, aquarist with the Aquarium of the Pacific (pers com 2022-12-19): “The female often pushes the male into guarding so she can roam. She will get very vocal, and demanding – making sure he does the job!”

*The Grunt Sculpin’s pointy “bill-like” head is reflected in the species’ scientific name.*

With regards to classification, the scientific name Rhamphocottus richardsonii reflects the Greek word for beak “rhamphos” which is appropriate for the Grunt Sculpin’s bill-like snout. This makes some people think that the species looks like a seahorse but note that they are not closely related at all. The Grunt Sculpin is the only member of its genus. It is truly one of a kind.

*Juvenile Grunt Sculpin #1 of 3 photos.*

Oh, and are you wondering about the name “Grunt” Sculpin? Apparently the species grunts when it is taken out of the ocean. You would too! Likely it also grunts when being defensive underwater. It is also the sound I make in my delight when I find one. It will be a very loud grunt indeed if I ever find one guarding eggs or with its tail-end extended out of a barnacle.

Below, more of my photos of Grunt Sculpins. 🙂

*Grunt Sculpin next to a Gold Dirona (nudibranch species). See him /her?*

*Grunt Sculpin and a Clown Dorid (another nudibranch species).*

*A Grunt Sculpin “strutting” over the ocean bottom. See the cloud of silt lifted off as a result?*

*Another Grunt Sculpin in an empty barnacle shell.*

*Grunt Sculpin hiding in a broken mussel shell.*

*I wonder if this one is female and about ready to lay her eggs?*

And some more photos of individuals to show how similar their markings are.

Sources:
– Aquarium of the Pacific – Grunt Sculpin
– Fishbase – Grunt Sculpin
– Love, M. S. (2011). Certainly more than you want to know about the fishes of the Pacific Coast: A postmodern experience. Santa Barbara, Calif: Really Big Press.

Buffalos Mating . . . Underwater!

That’s right, it’s mating season for buffalos . . . Buffalo SCULPINS that is!

Now that I’ve lured you to this posting with the procreation of a huge, shaggy terrestrial mammal on your mind . . . let me show you the spawn of this wondrous fish.

The Buffalo Sculpin – Enophrys bison – has earned the association with buffalo/bison due to the horn-like spine found on each gill plate (operculum). The species can be up to 37 cm long.

*Male Buffalo Sculpin guarding eggs © Jackie Hildering.*

As is the case for many species in the sculpin family, male Buffalo Sculpins guard the eggs from predators. They also fan the fertilized eggs with their pectoral fins to aerate them and stop growth of algae / bacteria. Sometimes they guard the eggs laid by multiple females (see below for a male that appeared to be trying to guard EIGHT egg masses). When you consider that a female can lay between 19,000 and 32,000 eggs, the males have a lot of fertilizing and guarding work to do! Their guard duty lasts 5 to 6 weeks until the eggs hatch.

Another male guarding eggs. If you look carefully, you will see the horn-like spines on the fish’s right gill plate. It is these horn-shaped gill protrusions that led to this species getting both its scientific and common name. ©Jackie Hildering.

*Same male as in the image above. ©Jackie Hildering.*

Many of the photos below show how you the males lie with their flat heads directly upon a cascade of eggs. The clusters of eggs laid in the spring allow me to find this incredibly camouflaged fish much more easily than I normally could. When I see a golden, orange or greenish shiny mass of eggs, I know a male Buffalo Sculpin has to be very near by. The bright colour of the eggs suggests that they might be toxic to many species, further protecting them from predation.

Very interestingly too, there is a species of fish known to parasitize on the care provided to the fertilized eggs by Buffalo Sculpins. Spinynose Sculpins (Asemichthys taylori) will lay their eggs on top of the Buffalo Sculpin eggs. The Spinynose Sculpin eggs will hatch faster and it is even possible that the presence of their eggs slows the development of the Buffalo Sculpin eggs. This “nesting parasitism”, is a “behavior previously unknown among marine fishes.” (Kent, Fisher, & Marliave, 2011).

As you can see, Buffalo Sculpins’ red, brown and pink colouration makes them very difficult to discern from the similarly brilliantly coloured life around them. They will remain absolutely still so as not to give away their presence. Their relative, the Red Irish Lord, has the same survival strategy. (See this previous blog item for photos and information on the Red Irish Lord.)

The camouflage, in addition to reducing the risk of predation by bigger fish and seals, allows the Buffalo Sculpin to be a very successful ambush hunter of shrimp, crabs, amphipods and small fish. It has been suggested that they eat mainly algae since this has so often been found in their gut but I am willing to bet that the algae ends up in their stomachs as a result of the Buffalo Sculpins grabbing prey ON the algae!

A cascade of eggs below this brilliantly coloured male Buffalo sculpin’s chin, April 1st., 2012 See below. He as still guarding these eggs on April 21st and was guarding other eggs on May 6th, 2012. ©Jackie Hildering.

*The two differently coloured egg masses suggest that this male is guarding the eggs from two different females. April 1, 2012. ©Jackie Hildering.*

*The same male guarding eggs 3 weeks later. April 21st, 2012.©Jackie Hildering.*

*Same male with a new egg mass – May 6, 2012. Checked in on him on May 20th, 2012 and he was no longer guarding eggs. ©Jackie Hildering*

Range: Monterey California to Kodiak Island, Gulf of Alaska. Most often found to a depth of 20 m but have been found to 227 m.

Spawn: February and March.

Sources: Kent, Daniel & Fisher, John & Marliave, Jeffrey. (2011). Interspecific nesting in marine fishes: Spawning of the spinynose sculpin, Asemichthys taylori, on the eggs of the buffalo sculpin, Enophrys bison. Ichthyological Research – ICHTHYOL RES. 58. 10.1007/s10228-011-0223-5.

Whoa! Photo below is of one male Buffalo Sculpin guarding the egg masses of at least 3 different females.
©Jackie Hildering.

And here’s a male appearing to guard EIGHT egg masses.

The following photos of male Buffalo Sculpins guarding eggs are intended to show how varied both the colouration of the fish and the eggs can be. All photos ©Jackie Hildering.