Humans and a multitude of beings we are acquainted with possess only a solitary vital organ known as the heart, which bears the responsibility of supplying precious life-giving blood to various regions of their corporeal form.
However, not all members of the animal kingdom adhere to this customary arrangement. Some creatures lack this crucial organ altogether, while others necessitate the presence of more than one heart to fulfill their physiological requirements, as a solitary heart would prove inadequate to sustain proper blood flow.
Examples of living beings endowed with multiple hearts encompass extraordinary creatures such as octopuses, squid, earthworms, cuttlefish, hagfish, and so forth.
Doesn’t it sound remarkably astonishing? For these fascinating organisms, possessing a multitude of hearts is simply part of their natural state.
Examples of Animals with Multiple Hearts
Here’s a compilation of intriguing creatures with multiple hearts:
1. Octopus
The common octopus, scientifically referred to as Octopoda, represents an animal order consisting of over 300 distinct species. This intriguing cephalopod is distinguished by its possession of eight limbs and a soft, pliant body.
Categorized within the same class as squids, nautiloids, and cuttlefish, this mollusk exhibits numerous bodily adaptations that aid its survival. Notably, it possesses up to three hearts.
The first and second hearts operate in a peripheral manner, diligently pumping blood that traverses through the gills to acquire the vital oxygenation. These hearts, termed branchial hearts, perform this crucial task. Meanwhile, the third heart, positioned centrally, assumes a unique role as the systemic heart, responsible for circulating oxygenated blood throughout the entirety of the creature’s physique.
2. Earthworm
Lumbricina, commonly known as earthworms, belong to the suborder Lumbricina within the phylum Annelida. These intriguing creatures, which inhabit diverse habitats worldwide, excluding Antarctica, are among the most prevalent invertebrates on our planet.
Earthworms thrive in environments characterized by soil, water, and optimal temperature conditions. Remarkably, these creatures lack traditional hearts but instead possess a system known as an aortic arch, which undertakes the functions typically performed by a heart.
This system comprises five vessels, one located above the digestive tract that propels blood forward, while the remaining four facilitate the backward flow of this vital fluid.
3. Cuttlefish
The cuttlefish, classified as Sepiida, is another captivating member of the Cephalopoda class, akin to the octopus. The term “cuttlefish” specifically refers to the order Sepiida, renowned for its possession of the intriguing cuttlebone.
Regarded as one of the most intelligent invertebrates currently inhabiting our world, cuttlefish exhibit remarkable traits. These fascinating creatures boast eight arms, two tentacles, and, intriguingly, three hearts.
Similar to their cephalopod counterparts, the hearts of cuttlefish function in a comparable manner. The branchial hearts receive oxygenated blood, which is subsequently distributed throughout the organism by the systemic heart. The primary difference lies in the pace at which this circulatory process unfolds. Cuttlefish possess blood abundant in hemocyanin, a compound containing less oxygen than hemoglobin, thereby imparting a unique characteristic to their cardiovascular system.
4. Hagfish
Scientifically known as Myxini, hagfish belong to the family Myxinidae within the order Myxiniformes and the class Myxini. These extraordinary creatures possess a skull but lack a vertebral column, a notable distinction that excludes them from the category of vertebrates.
An additional aspect that sets hagfish apart is their possession of four hearts, one classified as systemic and the remaining as auxiliary. Working together in harmony, these hearts play a vital role
in maintaining the functionality of the circulatory system. While the systemic heart dutifully pumps blood to all parts of the organism, the auxiliary heart provides assistance to ensure smooth operation.
5. Coastal Squid
Coastal squid, scientifically known as Myopsida, represents a term applied to the order Myopsida, which constitutes one of the four existing squid orders. These intriguing creatures can be found in coastal waters across the globe.
Coastal squid, although occasionally classified as a suborder, lack a universally accepted consensus on their categorization. One common thread, however, is their possession of three hearts, following a pattern akin to that observed in octopuses.
The systemic heart takes charge of blood pumping, while the auxiliary hearts facilitate its transport to the gills for oxygenation. Notably, the blood of coastal squid contains hemocyanin, a copper-rich substance, distinguishing it from other organisms.
6. Cockroaches
The infamous cockroach, recognized for its resilience, requires no extensive introduction. With an estimated 4,000 distinct species, these ubiquitous creatures have managed to establish a global presence. Nevertheless, only around 30 species coexist with humans, often labeled as pests. Cockroaches belong to the order Blattodea, with the family Blattidae encompassing the household varieties.
Have you ever pondered over the reason behind a cockroach’s uncanny ability to withstand eradication efforts? The answer lies within the astounding fact that these creatures possess a staggering 13 hearts, though there exists a debate concerning whether the additional 12 structures should be classified as hearts or chambers. Some experts opt to designate them as chambers. Irrespective of the nomenclature, the presence of all 13 interconnected entities facilitates the steady flow of blood throughout the cockroach’s body, contributing to its remarkable tenacity.
7. Trout
Trout, belonging to the subfamily Salmoninae within the family Salmonidae, represents a fascinating aquatic species. This subfamily encompasses seven genera, with Salmo, Salvelinus, and Oncorhynchus being classified as trouts.
Trouts exhibit a dual-hearted arrangement. The first heart, located in the throat like other fish, functions as a conventional organ, propelling blood to various parts of the creature’s anatomy. Meanwhile, the second heart, known as the caudal heart, occupies a position near the backbone.
8. Barosaurus
While all dinosaurs, including the barosaurus, have long vanished from our world, scientific research and analysis have shed light on intriguing aspects of their physiology. Fossil evidence indicates that the barosaurus, a magnificent creature that once roamed the Earth approximately 200 million years ago, possessed an elongated neck that facilitated its feeding from the tops of trees.
Due to its considerable size and remarkable neck length, paleontologists have postulated that the barosaurus might have possessed as many as eight hearts. Such a cardiovascular system would have been vital to ensure efficient blood circulation throughout the colossal body of this magnificent creature. However, it is important to note that this hypothesis remains the subject of ongoing debate among experts.
9. Horse
Equus ferus caballus, commonly referred to as the horse, stands as another captivating example. While horses do not possess multiple hearts in the conventional sense, they possess heart-like structures known as “frogs.” These organs, present in each foot, perform roles similar to that of the heart. Hence, when considering these additional structures alongside the primary heart, horses can be said to possess a total of five “hearts.” The frogs, with every stride the horse takes, actively pump blood into the horse’s arteries, carrying out functions analogous to those of a heart. Although not precisely classified as hearts, the frogs warrant their inclusion in this list.
10. Human
Lastly, we come to the human species, which may raise some eyebrows when considering the possibility of individuals possessing two hearts. While it is not the norm for humans to possess two hearts naturally, circumstances arise where this phenomenon becomes a reality. This occurs through heart transplantation, wherein a defunct heart is replaced with a new one. In cases where the original heart retains partial functionality, the transplanted heart joins forces with the existing organ, resulting in a reliance on two hearts instead of the customary single one. Although such occurrences are rare, they exemplify the adaptability of the human body.
Summary
In summary, while many creatures thrive with a solitary heart, the remarkable beings on this list necessitate the presence of multiple hearts to ensure their survival. Human exceptions aside, these diverse organisms exhibit distinct cardiovascular arrangements, with a central heart often supported by peripheral counterparts to fulfill the essential task of blood circulation.