Cirripedia | Earthling Nature

Tag Archives: Cirripedia

by Piter Keo | August 27, 2021 · 8:00 am

Friday Fellow: Striped Barnacle

by Piter Kehoma Boll

Barnacles are a peculiar group of sessile crustaceans and are common worldwide in the oceans, sometimes even living on the surface of marine animals such as mollusks, whales and turtles. Until now only one barnacle was featured here, a goose barnacle. So today we will know a species of the most common acorn barnacles, Amphibalanus amphitrite, known as the striped barnacle, purple acorn barnacle or Amphitrite’s rock barnacle.

The purple vertical stripes give the striped barnacle its name. Photo by iNaturalist user julieskrinni.*

The striped barnacle has the typical conical shape of acorn barnacles formed by six calcareous plates surrounding the body. The opening at the top has a diamond shape and is protected by a movable lid formed by two plates. The plates of the shell have a series of vertical brown to purple stripes, hence the name striped barnacle. To eat, the striped barnacle opens the lid and extends its long feathery legs, called cirri, through the opening to capture food particles from the water.

Submerged striped barnacles with their cirri exposed. Photo by Jason Lee Boswell.*

The exact origin of the striped barnacle is unknown, but it is likely native from the Indian ocean. However, due to human activities, it has been carried across the whole world and is now found in warm and temperate waters of all oceans.

As typical of barnacles, the striped barnacle is hermaphrodite. To reproduce, they use a very long penis that they insert inside adjacent barnacles to release sperm. The fertilized eggs are released in the water and develop first into a nauplius larva os crustaceans and later into the cyprid larva, which is the last stage before they become adults. The cyprid looks for an adequate substrate to settle and, once finding it, starts to secrete a glycoproteinous substance to attach the head on the substrate and undergoes the final metamorphosis to became a juvenile barnacle. They continue to molt as they keep growing after attaching to the substrate, but the calcarous plates do not molt with them, but continue to grow like the shell of a mollusk.

Several striped barnacles growing on the back of a horseshoe crab. Photo by iNaturalist user ozarkpoppy.*

The striped barnacle can grow on human-made structures, such as ships, pipes and other constructions exposed to the tides, and can become a nuisance, as its presence can decrease the efficacy of some of the colonized structures. As a result, it has become a target species of studies and is even a model organism for the study of larval settlement of barnacles. Even its genome has already been sequenced and several technologies are being tested to reduce its ability to colonize ships.

Not all studies with this species are directed to ways to getting rid of it, though. Due to the ease of breeding it in the lab, the striped barnacle is also used to study, for example, the impact of microplastics and ocean acidification on marine life.

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References and further reading:

Bhargava, S., Chen Lee, S. S., Min Ying, L. S., Neo, M. L., Lay-Ming Teo, S., & Valiyaveettil, S. (2018). Fate of nanoplastics in marine larvae: a case study using barnacles, Amphibalanus amphitrite. ACS Sustainable chemistry & engineering, 6(5), 6932-6940. https://pubs.acs.org/doi/abs/10.1021/acssuschemeng.8b00766

Burden, D. K., Spillmann, C. M., Everett, R. K., Barlow, D. E., Orihuela, B., Deschamps, J. R., … & Wahl, K. J. (2014). Growth and development of the barnacle Amphibalanus amphitrite: time and spatially resolved structure and chemistry of the base plate. Biofouling, 30(7), 799-812. https://doi.org/10.1080/08927014.2014.930736

Maréchal, J. P., & Hellio, C. (2011). Antifouling activity against barnacle cypris larvae: Do target species matter (Amphibalanus amphitrite versus Semibalanus balanoides)?. International Biodeterioration & Biodegradation, 65(1), 92-101. https://doi.org/10.1016/j.ibiod.2010.10.002

McDonald, M. R., McClintock, J. B., Amsler, C. D., Rittschof, D., Angus, R. A., Orihuela, B., & Lutostanski, K. (2009). Effects of ocean acidification over the life history of the barnacle Amphibalanus amphitrite. Marine Ecology Progress Series, 385, 179-187. https://doi.org/10.3354/meps08099

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Friday Fellow: Common Goose Barnacle

by Piter Kehoma Boll

The open surface of the oceans may at first look like a large lifeless sheet. However, if you look closer, you’ll see that there is much more life there than you could imagine. And it does not only include the microscopic plankton that floats in the water column, but also large organisms that dwell right at the boundary between the water and the air. These creatures are called the neuston and come in several shapes and one of them is Lepas anserifera, or the common goose barnacle.

Several common goose barnacles found growing on a cuttlebone in India’s west coast. Their modified legs (cirri) are out looking for food. Photo by Abhishek Jamalabad.*

The common goose barnacle is found in tropical and subtropical waters all around the world. It belongs to the subclass Cirripedia, a peculiar group of crustaceans commonly known as barnacles. They live attached to the substrate and are hemaphrodites, both features that are uncommon among arthropods. Within the barnacles, the common goose barnacle belongs to the order Pedunculata, or goose barnacles, which are characterized by the presence of a stalk that attaches them to the substrate.

Common goose barnacles in Taiwan. A younger specimen is seen growing on a larger one. Photo by Liu JimFood.*

The substrate chosen by the common goose barnacle is almost exclusively floating material. This material, which includes sea weeds and all sort of debris, such as pieces of wood, coconuts or animal carcasses, rarely remains floating for a long time, either because its decay makes it sink or fall apart or because it ends up on the shore. Thus, the goose barnacle has to find a way to complete its life cycle very quickly, and that is what it does.

Common goose barnacles growing on an apple that must have floated for some time and ended up at the shore in the state of Bahia, Brazil. Photo by iNaturalist user kuroshio.**

Common goose barnacles growing on a light bulb washed ashore in Palau Pinang, Malaysia. Photo by Al Kordesch.

Goose barnacles start their lives as a planktonic one-eyed larva that, after five stages, develops into another larval form known as cyprid. The cyprid’s only purpose is to find a suitable surface to live and, once it finds it, it secretes a glycoproteinaceous substance that attaches it to the substrate by the head. It then develops into the adult animal and secretes a series of calcified plates that surrounds its body. The adults use their feathery legs (cirri) to capture food, mostly plankton, and carry it inside their shell.

Common goose barnacles growing on a brush washed ashore in New Jersey, USA. Photo by Stan Rullman.**

Due to human activities, the amount of floating material on the ocean surfaces increased greatly. Thus, the number of available substrates for the goose barnacle to grow also increased, and so likely did its population. Unfortunately, the human-generated floating material also includes a lot of small plastic particles, and goose barnacles frequently ingest them together with food. Although the harm caused by ingesting plastic particles has not been assessed yet, they certainly do not improve the barnacle’s health.

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Reference:

Goldstein MC, Goodwin DS (2013) Gooseneck barnacles (Lepas spp.) ingest microplastic debris in the North Pacific Subtropical Gyre. PeerJ 1: e184. doi: 10.7717/peerj.184

Inatsuchi A, Yamato S, Yusa Y (2010) Effects of temperature and food availability on growth and reproduction in the neustonic pedunculate barnacle Lepas anserifera. Marine Biology 157(4): 899–905. doi: 10.1007/s00227-009-1373-0

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* This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.