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Marine Life & Conservation Blogs

The blue-ringed octopus: a beautiful but dangerous creature (Watch Video)

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The third in an exciting new series of blogs introducing some of the amazing marine life you can encounter at Magic Resorts in the Philippines…

One of the most popular octopuses that’s high on almost every divers’ bucket lists, is the blue-ringed octopus. The aptly named creature gets its name from the blue rings on its skin. These creatures usually turn out smaller than everyone’s expectations, but don’t underestimate the power of these critters!

Did you know that the blue-ringed octopus is actually one of the most venomous animals in the world? You definitely don’t want to make this creature angry. So how do you know that you have gone too far and annoyed the octopus? This creature will warn you! Usually a dark brown to yellow color with blue patches or rings, it will turn darker and the blue rings will become brighter and brighter! Though usually shy in nature, if they are stepped on or angered, they will bite!

This little octopus produces two types of venom – one for protection and one for hunting. The one for protection is produced by bacteria that live in its salivary glands. The tetrodotoxin it produces is the same deadly toxin that pufferfishes have. Experiments show that one single blue-ringed octopus has enough venom to fatally paralyze 26 adult humans… at the same time! Unfortunately, there is no antivenom yet and treatment requirements include life-support machines such as artificial ventilation.

There is not just one type of blue-ringed octopus though, there are at least 10 different species which can be found in tidal pools and reefs in the Indo-Pacific Ocean.

During the night, these little octopuses will search for food. They tend to hunt for crabs, clams, shrimps, small fish, etc. But they also have to be wary of their predators, mainly eels.

Fun fact: when a blue-ringed octopus loses a tentacle, it will grow back automatically!

Come and dive at Magic Oceans and let the guides show you these docile blue-ringed octopuses in Anda, Bohol. The guides will help you capture that perfect picture, and you can witness how the little octopus goes about its daily life.

Some general facts!

  • Blue-ringed octopuses can have up to 50 – 60 blue rings on their skin.
  • They are roughly 5 – 8 inches in size.
  • The bite of a blue-ringed octopus is usually reported as painless
  • They tend to have a life expectancy of up to 2 years and lay 50-100 eggs when they mate.

Visit Magic Oceans Anda, Bohol and Magic Island Moalboal, Cebu… find out more at www.magicresorts.online.

Also on Facebook, Pinterest and Instagram!

Magic Resorts Philippines has two dive resorts: Magic Oceans Anda, Bohol and Magic Island Moalboal, Cebu. Have the Magic experience in two different locations. Rely on the same atmosphere, service and standards during every vacation! Blogs are supported by Marlon Managa, Dive Master and Marine Biologist at Magic Oceans.

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Evolution of Manatees in Florida

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manatee

Op-ed by Beth Brady, PhD, Senior Science and Conservation Associate, Save the Manatee® Club

Recent news articles and broadcasts have claimed that manatees are not native to Florida or only arrived on Florida’s west coast in the 1950s. These claims, based on limited anthropological records, point to where manatees were historically exploited by humans and assume that a lack of evidence means manatees were absent from certain areas. However, absence of evidence is not evidence of absence—it’s like looking for stars in the daytime; just because you can’t see them doesn’t mean they’re not there. Moreover, genetic and fossil evidence indicate manatees have been present in Florida for the last 12,000 years.

The Florida Fish and Wildlife Conservation Commission (FWC), which manages Florida manatee populations, has created a manatee timeline highlighting key dates and notable information about manatee presence in Florida (https://myfwc.com/education/wildlife/manatee/timeline/). Historical records suggest that manatees have been observed in Florida as far back as the 1500s, with some details presented by the Florida Fish and Wildlife timeline aligning with evidence presented in the publication.

manatee

Manatee species, such as the African manatee and the Antillean manatee, continue to be poached by humans (Marsh et al., 2022). As a result, these species are difficult to observe in the wild and may adapt by foraging at night to avoid human encounters (Rycyk et al., 2021). This behavior could help explain why historical Florida manatee populations that were hunted by humans are absent from middens and rarely mentioned in historical accounts.

Further, the publication only briefly touches on the paleontological record and genetic evidence, which indicate that manatees have existed in Florida for a much longer period. Fossil and genetic evidence reveal a rich history of manatees in Florida. Manatees belong to the order Sirenia, which includes the Amazonian, African, and West Indian manatee species. While Sirenian fossils have been found globally, only Florida and the Caribbean contain specimens from every epoch over the past 50 million years (Reep and Bonde, 2006). The modern manatee, as we know it, emerged in the Caribbean about 2 million years ago (Domning, 1982).

The evolution of manatees during the Pleistocene epoch provides valuable insights into how environmental changes shaped their distribution and genetic diversity. During the Pleistocene epoch (2.59 million to 11,700 years ago), there were roughly 20 cycles of long glacial periods (40,000–100,000 years) followed by shorter interglacial periods lasting around 20,000 years. At the start of these warmer periods, Caribbean manatees migrated northward with the warming waters (Reep and Bonde, 2006). Water currents and thermal barriers isolated these manatees from populations in Mexico and the Caribbean, leading to genetic divergence. Fossil evidence indicates that Trichechus manatus bakerorum lived in Florida and North Carolina about 125,000 years ago but did not survive the last glacial period, which began 100,000 to 85,000 years ago (Domning, 2005). This subspecies was eventually replaced by modern Florida manatees.

This evolutionary theory is further supported by genetic evidence. Research indicates that Florida manatees trace their evolutionary origins to Caribbean ancestors that migrated northward over the past 12,000 years (Garcia-Rodriguez et al., 1998). A 2012 study by Tucker et al. reinforces this theory, showing higher genetic diversity in manatees on Florida’s west coast compared to those on the east. Over time, core populations migrated northward, with some groups moving south and east along the Florida coastline before heading north along the Atlantic. This migration pattern left the west coast population with greater genetic diversity, while the east coast population retained only a smaller subset. These findings suggest that the founding population of Florida manatees—arriving approximately 12,000 years ago—originated along Florida’s southwestern coast, which became the center of the state’s manatee population (Reep and Bonde, 2006). The process of vicariance further supports this hypothesis; as geographic and ecological barriers emerged, they likely isolated the Florida manatee populations from their Caribbean ancestors. This isolation likely limited migration back and forth between regions, fostering the establishment of local populations in southwestern Florida.

manatee

Manatees are not only a cherished symbol of Florida’s natural heritage but also a species with deep evolutionary and historical ties to the region. In sum, despite recent claims questioning their nativity, extensive fossil and genetic evidence confirms that manatees have been present in Florida’s waters for thousands of years, with ancestors dating back over 12,000 years. We agree with the authors of the published article that protecting these iconic creatures and their habitats is essential to preserving Florida’s unique ecological identity for future generations

Beth Brady is the Senior Science and Conservation Associate at Save the Manatee Club whose work focuses on manatee biology and conservation. She has her PhD from Florida Atlantic University and her Master’s in Marine Science from Nova Southeastern University.

savethemanatee.org

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Saba’s Plan for a Coral Comeback

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Saba

Saba has an exciting new initiative to restore its coral reefs. This new project, running from 2024 to 2026, will focus on reviving key species in the island’s underwater ecosystems. With a collaborative team from the Saba Conservation Foundation (SCF) and Van Hall Larenstein (VHL) University of Applied Sciences, the project aims to restore both corals as well as sea urchins.

This initiative is centered around coral restoration, specifically reviving two essential coral species—staghorn coral (Acropora cervicornis) and elkhorn coral (Acropora palmata).  By mapping parent colonies and using a technique known as coral gardening, SCF will create and maintain coral nurseries. These corals will eventually be outplanted at key reef sites around Saba to not only expand the number of coral colonies, but also provide essential fish habitat. The project focusses on installing coral nurseries, training staff with the newest techniques and starting with the restoration of key reef sites.

Saba

Reef Cleaners to the Rescue

It’s not just corals getting a makeover—this project also shines a spotlight on the essential role of grazers, particularly sea urchins. VHL is leading the charge on cultivating and restocking two key sea urchin species, West Indian sea egg (Tripneustes) and long-spined sea urchin (Diadema), known for their ability to keep algae in check. By removing algae, which are important competitors of corals, they help the coral to thrive. By restoring these “reef cleaners,” Saba’s project will give corals the breathing room they need to grow, setting the stage for a healthier, more balanced marine ecosystem.

From Tiny Urchins to Big Goals

The project will be funded as part of the Dutch Government’s Nature and Environment Policy Plan (NEPP) 2020-2030 for the Caribbean Netherlands, a comprehensive initiative aimed at conserving and restoring the unique natural environments of the Dutch Caribbean islands, including Saba, St. Eustatius, and Bonaire. This project is aiming for big milestones:  build and maintaining coral nurseries, the expansion of urchin cultivation facilities, and the creation of a dedicated research center. By 2026, the project hopes to ramp up coral and grazer restoration, with the ultimate goal of extending these efforts across the Dutch Caribbean. By linking local initiatives to broader regional goals, Saba’s restoration project promises to leave a lasting impact on both the environment and the community.

Find out more about the DCNA at dcnanature.org.

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