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{{Short description|Unidentified marine animal}}{{About|the unidentified marine animal named after the vessel it was sighted on|the [[marine mammal]]|Dolphin}}[[File:Dolphin 1 Animal illustration.png|thumb|An illustration of the Dolphin 1 Animal with a size comparison to human diver. ”[[Blanket octopus|Tremoctopus]]” added to demonstrate the [[Morphology (biology)|morphological]] similarity between the species.]]
{{Short description|Unidentified marine animal}}{{About|the unidentified marine animal named after the vessel it was sighted on|the [[marine mammal]]|Dolphin}}[[File:Dolphin 1 Animal illustration.png|thumb|An illustration of the Dolphin 1 Animal with a size comparison to human diver. ”[[Blanket octopus|Tremoctopus]]” added to demonstrate the [[Morphology (biology)|morphological]] similarity between the species.]]
The ”’Dolphin 1 animal”’, also referred to as ”’Gwenith Penry’s blob”’, or simply ”’mystery animal”’ is an unidentified [[Marine life|marine animal]] that was observed and [https://tonmo.com/threads/unknown-phylum-any-suggestions.7469/ photographed] off the coast of [[South Africa]] in 2007. The animal most resembles a [[cephalopod]] in outward appearance.<ref name=”TONMO”>{{cite web |last1=O’Shea |first1=Steve |title=Unknown Phylum. Any suggestions? |url=https://tonmo.com/threads/unknown-phylum-any-suggestions.7469/ |website=Tonmo; The Octopus News Magazine Online |publisher=Deep Intuition, LLC |access-date=3 February 2026}}</ref> It was observed by the crew of the Dolphin 1, and is often connoted in correlation to the vessel’s name. The scientific name, ”Hepatomares striata” (roughly translating to ‘striped liver’ in [[Latin]]), was proposed in jest due to the species’ resemblence to a striped [[liver]].<ref name=”TONMO” />
The ”’Dolphin 1 animal”’, also referred to as ”’Gwenith Penry’s blob”’, or simply ”’mystery animal”’ is an unidentified [[Marine life|marine animal]] that was observed and [https://tonmo.com/threads/unknown-phylum-any-suggestions.7469/ photographed] off the coast of [[South Africa]] in 2007. The animal most resembles a [[cephalopod]] in outward appearance.<ref name=”TONMO”>{{cite web |last1=O’Shea |first1=Steve |title=Unknown Phylum. Any suggestions? |url=https://tonmo.com/threads/unknown-phylum-any-suggestions.7469/ |website=Tonmo; The Octopus News Magazine Online |publisher=Deep Intuition, LLC |access-date=3 February 2026}}</ref> It was observed by the crew of the Dolphin 1, and is often connoted in correlation to the vessel’s name. The scientific name, ”Hepatomares striata” (roughly translating to ‘striped liver’ in [[Latin]]), was proposed in jest due to the species’ to a striped [[liver]].<ref name=”TONMO” />
The animal is membranous in appearance, with a rounded body that tapers towards the [[anterior]] edge of the body. Most intriguingly, the subject of the photos seems to have a ‘nose’ or proboscis at the anterior, which is most apparent in one photo but largely absent from the other three.<ref name=”TONMO” /> The body was estimated at 30-40cm (12-16in) long with a thickness of 5-10cm (4-6in) around the anterior end.<ref name=”TONMO” /> It possessed what has been referred to as a ‘skirt’ around the posterior end, likely comprised of two appendages wrapped around the posterior that meet at the tips rather than a single contiguous structure like the flap of a [[Ray (animal)|ray]].<ref name=”TONMO” /> This skirt was estimated to be around 2-5cm (0.8-2in) thick.<ref name=”TONMO” /> The dorsum is entirely a greyish mauve colour and in some photos, the underside appears to potentially be a lighter cream (evident of [[countershading]]). The skirt is banded with white and a dark reddish orange, and the tip of the ‘nose’ is white. In one photo, two large divots (likely pores) and a vent are visible, as well as a ruddy orange colouration on the underbelly and behind the vent.<ref name=”TONMO” /> In one photo, it appears to potentially have a [[Melon (cetacean)|melon]]-like structure on its ‘head’ however, this may be air trapped in its mantle (if it is a cephalopod).<ref name=”TONMO” />
The animal is membranous in appearance, with a rounded body that tapers towards the [[anterior]] edge of the body. Most intriguingly, the subject of the photos seems to have a ‘nose’ or proboscis at the anterior, which is most apparent in one photo but largely absent from the other three.<ref name=”TONMO” /> The body was estimated at 30-40cm (12-16in) long with a thickness of 5-10cm (4-6in) around the anterior end.<ref name=”TONMO” /> It possessed what has been referred to as a ‘skirt’ around the posterior end, likely comprised of two appendages wrapped around the posterior that meet at the tips rather than a single contiguous structure like the flap of a [[Ray (animal)|ray]].<ref name=”TONMO” /> This skirt was estimated to be around 2-5cm (0.8-2in) thick.<ref name=”TONMO” /> The dorsum is entirely a greyish mauve colour and in some photos, the underside appears to potentially be a lighter cream (evident of [[countershading]]). The skirt is banded with white and a dark reddish orange, and the tip of the ‘nose’ is white. In one photo, two large divots (likely pores) and a vent are visible, as well as a ruddy orange colouration on the underbelly and behind the vent.<ref name=”TONMO” /> In one photo, it appears to potentially have a [[Melon (cetacean)|melon]]-like structure on its ‘head’ however, this may be air trapped in its mantle (if it is a cephalopod).<ref name=”TONMO” />
The animal stayed at the surface, initially appearing about 30cm (12in) beneath the water before surfacing further and exposing some of its body.<ref name=”TONMO” /> It lifted its nose towards the vessel as if sensing if something was in front of it, potentially implying that the nose may be a sensory organ. This interaction was photographed.<ref name=”TONMO” /> The animal swam away after the initial sighting. It was suspected that it was propelling itself relatively slowly through the water by using vents in a similar manner to known [[Squid|squids]] and [[Octopus|octopi]]. It moved with its nose leading.<ref name=”TONMO” />
The animal stayed at the surface, initially appearing about 30cm (12in) beneath the water before surfacing further and exposing some of its body.<ref name=”TONMO” /> It lifted its nose towards the vessel as if sensing if something was in front of it, potentially implying that the nose may be a sensory organ. This interaction was photographed.<ref name=”TONMO” /> The animal swam away after the initial sighting. It was suspected that it was propelling itself relatively slowly through the water by using vents in a similar manner to known [[Squid|squids]] and [[Octopus|octopi]]. It moved with its nose leading.<ref name=”TONMO” />
During the sighting, a pod of 200+ [[Bottlenose dolphin|bottlenose dolphins]] was feeding nearby, however, neither the dophins nor the animal paid mind to one another.<ref name=”TONMO” />
During the sighting, a pod of 200+ [[Bottlenose dolphin|bottlenose dolphins]] was feeding nearby, however, neither the nor the animal one another.<ref name=”TONMO” />
==Reaction and Potential Identity==
==Reaction and Potential Identity==
The photos of the Dolphin 1 animal were posted on the 6th of April, 2007 to cephalopod news forum/online magazine, Tonmo, by Dr. Steve O’Shea after gaining permission by photographer Dr. Gwenith Penry.<ref name=”TONMO” /> The thread, entitled; “Unknown Phylum. Any suggestions?” accumulated much attention from the community by both hobbyists and [[Biologist|biologists]] alike due to the cryptic nature of the species. Theories of the animal’s identity ranged from it being a ”Tremoctopus” (a genus comprised of blanket octopi species and the sole genus in its family, ”Tremoctopodidae”) a [[Hexabranchus|dancing sea slug]], a [[sea cucumber]], [[sea hare]], or even potentially a [[sharptail mola|sharp-tailed sunfish]] (”Masturus lanceolatus”), [[Cindaria|jellyfish]], or ray.<ref name=”TONMO” /> The prevailing notion however, is that it was a cephalopod, likely ”Tremoctopus”. Despite this, the hypothesis that it was a dancing sea slug species was also discussed, with one user claiming they presented the photo to a group of divers who agreed with the conclusion that the animal was a sea slug.<ref name=”TONMO” />
The photos of the Dolphin 1 animal were posted on the 6th of April, 2007 to cephalopod news forum/online magazine, Tonmo, by Dr. Steve O’Shea after gaining permission by photographer Dr. Gwenith Penry.<ref name=”TONMO” /> The thread, entitled; “Unknown Phylum. Any suggestions?” accumulated much attention from the community by both hobbyists and [[Biologist|biologists]] alike due to the cryptic nature of the species. Theories of the animal’s identity ranged from it being a ”Tremoctopus” (a genus comprised of blanket octopi species and the sole genus in its family, ”Tremoctopodidae”) a [[Hexabranchus|dancing sea slug]], a [[sea cucumber]], [[sea hare]], or even potentially a [[sharptail mola|sharp-tailed sunfish]] (”Masturus lanceolatus”), [[Cindaria|jellyfish]], or ray.<ref name=”TONMO” /> The prevailing notion however, is that it was a cephalopod, likely ”Tremoctopus”. Despite this, the hypothesis that it was a dancing sea slug was also discussed, with one user claiming they presented the photo to a group of divers who agreed with the conclusion that the animal was a sea slug.<ref name=”TONMO” />
===Other explanations===
===Other explanations===
Multiple non-animal explanations were given for the identity of the Dolphin 1 animal that do not refer to specific species. Some more outlandish explanations from the original thread posit that the creature was actually a detatched dolphin [[placenta]] that appeared to move due to the current, or that the specimen was a result of [[formaldehyde |formaldehyde contamination]] in offshore South Africa.<ref name=”TONMO” /> Dr. O’Shea himself stated that he believed the animal to be a [[vertebrate]] rather than an [[invertebrate]], and that it was likely an unrecognised species of tail-less ray.<ref name=”TONMO” />
Multiple non-animal explanations were given for the identity of the Dolphin 1 animal that do not refer to specific species. Some more outlandish explanations from the original thread posit that the creature was actually a dolphin [[placenta]] that appeared to move due to the current, or that the specimen was a result of [[formaldehyde |formaldehyde contamination]] in offshore South Africa.<ref name=”TONMO” /> Dr. O’Shea himself stated that he believed the animal to be a [[vertebrate]] rather than an [[invertebrate]], and that it was likely an unrecognised species of tail-less ray.<ref name=”TONMO” />
==Comparing the Dolphin 1 animal to known species==
==Comparing the Dolphin 1 animal to known species==
===Tremoctopus===
===Tremoctopus===
The Dolphin 1 animal is most frequently compared to a ”Tremoctopus”, the blanket octopus genus. Blanket octopi exhibit very superficially similar morphology to the Dolphin 1 animal, possessing a gently elongated oval-shaped mantle, and two large primary arms that are often banded in a similar fashion to the skirt of the animal. The body of the blanket octopus is also a similar shape and similarly muscular.<ref name=”1977OCTOPUS”>{{cite journal |last1=Thomas |first1=Ronald F. |title=Systematics, Distribution, and Biology of Cephalopods of the Genus Tremoctopus (Octopoda: Tremoctopodidae) |journal=Bulletin of Marine Science |date=1977 |volume=27 |issue=3 |url=https://www.ingentaconnect.com/content/umrsmas/bullmar/1977/00000027/00000003/art00001# |access-date=7 February 2026 |publisher=University of Miami – Rosenstiel School of Marine, Atmospheric & Earth Science}}</ref> Perhaps the most frequently used piece of evidence for the conclusion that the animal was a ”Tremoctopus” is the superficial similarlities between both, with both possessing a dull purple-grey dorsal colouration, a lighter ventral colouration<ref name=”TONMO” /> and similarly banded arms<ref name=”TONMO” /> (skirt in the Dolphin 1 animal). One photo of the Dolphin 1 animal also clearly exhibits aquiporous pores on its dorsal side,<ref name=”TONMO” /> a characteristic feature of the blanket octopus only seen elsewhere in the genus ”[[Ocythoe]]”, but even in saying that, the species of this genus have their pores exclusively on the ventral side.<ref name=”1977OCTOPUS” /> The pores on ”Tremoctopus” are positioned between the eyes,<ref name=”TONMO” /> however, no discernable eyes are visible in any of the photos of the Dolphin 1 animal.<ref name=”1977OCTOPUS” />
The Dolphin 1 animal is most frequently compared to a ”Tremoctopus”, the blanket octopus genus. Blanket octopi exhibit very superficially similar morphology to the Dolphin 1 animal, possessing a gently elongated oval-shaped mantle, and two large primary arms that are often banded in a similar fashion to the skirt of the animal. The body of the blanket octopus is also a similar shape and similarly muscular.<ref name=”1977OCTOPUS”>{{cite journal |last1=Thomas |first1=Ronald F. |title=Systematics, Distribution, and Biology of Cephalopods of the Genus Tremoctopus (Octopoda: Tremoctopodidae) |journal=Bulletin of Marine Science |date=1977 |volume=27 |issue=3 |url=https://www.ingentaconnect.com/content/umrsmas/bullmar/1977/00000027/00000003/art00001# |access-date=7 February 2026 |publisher=University of Miami – Rosenstiel School of Marine, Atmospheric & Earth Science}}</ref> Perhaps the most frequently used piece of evidence for the conclusion that the animal was a ”Tremoctopus” is the superficial between both, with both possessing a dull purple-grey dorsal colouration, a lighter ventral colouration<ref name=”TONMO” /> and similarly banded arms<ref name=”TONMO” /> (skirt in the Dolphin 1 animal). One photo of the Dolphin 1 animal also clearly exhibits aquiporous pores on its dorsal side,<ref name=”TONMO” /> a characteristic feature of the blanket octopus only seen elsewhere in the genus ”[[Ocythoe]]”, but even in saying that, the species of this genus have their pores exclusively on the ventral side.<ref name=”1977OCTOPUS” /> The pores on ”Tremoctopus” are positioned between the eyes,<ref name=”TONMO” /> however, no discernable eyes are visible in any of the photos of the Dolphin 1 animal.<ref name=”1977OCTOPUS” />
This is not to say that the species is conclusively ”Tremoctopus”, as a variety of difference exist between it and known members of the genus. For instance, blanket octopi are named in reference to the extravagant web-like “blanket” that stretches between the two main arms on the females<ref name=”1977OCTOPUS” /> (”Tremoctopus” are incredibly [[sexually dimorphic]]) a feature which is definitively absent from the specimen in the photos.<ref name=”TONMO” /> It is possible that this individual may be a male, as male blanket octopi do not possess the blanket, however, male blanket octopi are far smaller than the reported size of the Dolphin 1 animal, ranging as small as 4.9mm (0.2in) in length.<ref name=”1977OCTOPUS” /> It may simply have been tucking its other tentackles beneath its body as blanket octopi have been known to do while swimming, or have had its webbing torn off by predation.<ref name=”TONMO” /> It has been proposed also that the animal was sick or ill when the photos were taken, leading to its seemingly confused movements towards the vessel.<ref name=”TONMO” /> This behaviour is exhibited in countless other deep sea marinelife, which often become disoriented and move towards shallower waters when dying or diseased. ”Tremoctopus” also possess quite obvious large eyes, a greater number of arms, and a generally more conical shape and clearer demarkation between the head and mantle than the Dolphin 1 animal.<ref name=”1977OCTOPUS” /> Blanket octopi also possess obvious suckers,<ref name=”1977OCTOPUS” /> a trait absent from descriptions and photos of the Dolphin 1 animal.<ref name=”TONMO” /> It cannot be reliably declared tha tthe animal did not possess them, as the positions in which it held its ‘arms’ potentially left any existing suckers obscured. The position by which the animal carried its ‘arms’ is also not consistent with ”Tremoctopus”.<ref name=”TONMO” /><ref name=”1977OCTOPUS” /> ”Tremoctopus” also lacks the sensory ‘nose’ that the animal possesses, and while some claim in the original thread that the nose is just an extension of the mantle that appears nose-like due to its reflection against the water’s surface, Dr. O’Shea’s account of its independent movement from the body likely distinguishes it as a unique sensory structure.<ref name=”TONMO” />
This is not to say that the species is conclusively ”Tremoctopus”, as a variety of difference exist between it and known members of the genus. For instance, blanket octopi are named in reference to the extravagant web-like “blanket” that stretches between the two main arms on the females<ref name=”1977OCTOPUS” /> (”Tremoctopus” are incredibly [[sexually dimorphic]]) a feature which is definitively absent from the specimen in the photos.<ref name=”TONMO” /> It is possible that this individual may be a male, as male blanket octopi do not possess the blanket, however, male blanket octopi are far smaller than the reported size of the Dolphin 1 animal, ranging as small as 4.9mm (0.2in) in length.<ref name=”1977OCTOPUS” /> It may simply have been tucking its other beneath its body as blanket octopi have been known to do while swimming, or have had its webbing torn off by predation.<ref name=”TONMO” /> It has been proposed also that the animal was sick or ill when the photos were taken, leading to its seemingly confused movements towards the vessel.<ref name=”TONMO” /> This behaviour is exhibited in countless other deep sea , which often become disoriented and move towards shallower waters when dying or diseased. ”Tremoctopus” also possess quite obvious large eyes, a greater number of arms, and a generally more conical shape and clearer demarkation between the head and mantle than the Dolphin 1 animal.<ref name=”1977OCTOPUS” /> Blanket octopi also possess obvious suckers,<ref name=”1977OCTOPUS” /> a trait absent from descriptions and photos of the Dolphin 1 animal.<ref name=”TONMO” /> It cannot be reliably declared animal did not possess them, as the positions in which it held its ‘arms’ potentially left any existing suckers obscured. The position by which the animal carried its ‘arms’ is also not consistent with ”Tremoctopus”.<ref name=”TONMO” /><ref name=”1977OCTOPUS” /> ”Tremoctopus” also lacks the sensory ‘nose’ that the animal possesses, and while some claim in the original thread that the nose is just an extension of the mantle that appears nose-like due to its reflection against the water’s surface, Dr. O’Shea’s account of its independent movement from the body likely distinguishes it as a unique sensory structure.<ref name=”TONMO” />
===Hexabranchus===
===Hexabranchus===
[[File:Yellow-margined Spanish Dancer.jpg|thumb|[[Yellow-margined Spanish dancer]] (”H. aureomarginatus”)]]”Hexabranchus” is a [[Mollusca|mollusc]] genus that is comprised of the dancing sea slugs, large [[Pelagic zone|pelagic]] [[Nudibranch|nudibranchs]] belonging to the family ”Hexabranchidae”.<ref name=”MALAQUIAS”>{{cite web |last1=Tibiriçá |first1=Yara |last2=Pola |first2=Marta |last3=Pittman |first3=Cory |last4=Gosliner |first4=Terrence M. |last5=Malaquias |first5=Manuel A. |last6=Cervera |first6=Juan Lucas |title=A Spanish dancer? No! A troupe of dancers: a review ofthe family Hexabranchidae Bergh, 1891 (Gastropoda, Heterobranchia, Nudibranchia) |url=https://biblioteca.biofund.org.mz/wp-content/uploads/2023/07/1688639011-2023_Hexabranchus.pdf |website=BioFund |publisher=Organisms Diversity and Evolution |access-date=7 February 2026}}</ref> Dancing sea slugs do not appear similar in appearance to the Dolphin 1 animal in any relevant way excluding their similarly amorphous bodies. In terms of morphology, ”Hexabranchus” species possess various traits which distinguish them from the specimen in the photographs, chiefly their [[Rhinophore|rhinophores]] and far more pronounced skirts/margins around their mantles.<ref name=”MALAQUIAS” /> The vast majority of ”Hexabranchus” species possess a ruddy, blood, or deep red-orange colouration with white-mottling -as in the [[Spanish dancer]] (”H. sanguineus”) or yellow-margined Spanish dancer,<ref name=”MALAQUIAS” /> a colouration that is completley inconsistent with the greyish purple of the Dolphin 1 animal.<ref name=”TONMO” /> Juvenile dancers are a translucent shade with purplish spotted accents,<ref name=”MALAQUIAS” /> more closely resembling the Dolphin 1 animal than their adult coutnerparts but still being incomparable to the animal’s solid colouration. The shape of the body is also a point of contention, as dancers possess a flat pill-shaped body<ref name=”MALAQUIAS” /> that is inconsistent with the tapered-ovular shape of the Dolphin 1 animal.<ref name=”TONMO” /> Upon presenting the photographs to a team of divers, one user in the original thread had concluded the Dolphin 1 animal to be a dancer based on their collective identification of the animal as such.<ref name=”TONMO” /> The user proposed that the “questing forward nose” along with its locomotion was indicative of characteristic swimming styles of dancers, though this conclusion received significant pushback from Dr. O’Shea and various other users.<ref name=”TONMO” /> Dancers swim in a very particular dorso-ventral undulating motion<ref name=”MALAQUIAS” /> that isinconsistent with the way that the movement of the animal was described. The skirt of the Dolphin 1 animal also fails to match the margins or skirts exhibited among dancers, as it was likely comprised of two appendages wrapped to meeting, whereas in ”Hexabranchus” species, the margin is an unbroken skirt of membranous tissue that is often crumbled or crinkled when swimming. The photographs also do not present any rhinophores, which are characteristic of sea slugs and nudibranchs. Some users believed the animal to be inverted or upside down,<ref name=”TONMO” /> implying the conclusion that the rhinophores may have been obscured if it did possess any. Many users also claimed that the animal was far too big for a sea slug, as most dancers reach a maximum length of about 22cm (8.7in).<ref name=”MALAQUIAS” />
[[File:Yellow-margined Spanish Dancer.jpg|thumb|[[Yellow-margined Spanish dancer]] (”H. aureomarginatus”)]]”Hexabranchus” is a [[Mollusca|mollusc]] genus that is comprised of the dancing sea slugs, large [[Pelagic zone|pelagic]] [[Nudibranch|nudibranchs]] belonging to the family ”Hexabranchidae”.<ref name=”MALAQUIAS”>{{cite web |last1=Tibiriçá |first1=Yara |last2=Pola |first2=Marta |last3=Pittman |first3=Cory |last4=Gosliner |first4=Terrence M. |last5=Malaquias |first5=Manuel A. |last6=Cervera |first6=Juan Lucas |title=A Spanish dancer? No! A troupe of dancers: a review ofthe family Hexabranchidae Bergh, 1891 (Gastropoda, Heterobranchia, Nudibranchia) |url=https://biblioteca.biofund.org.mz/wp-content/uploads/2023/07/1688639011-2023_Hexabranchus.pdf |website=BioFund |publisher=Organisms Diversity and Evolution |access-date=7 February 2026}}</ref> Dancing sea slugs in appearance to the Dolphin 1 animal excluding their similarly amorphous bodies. In terms of morphology, ”Hexabranchus” species possess various traits which distinguish them from the specimen in the photographs, chiefly their [[Rhinophore|rhinophores]] and far more pronounced skirts/margins around their mantles.<ref name=”MALAQUIAS” /> The vast majority of ”Hexabranchus” species possess a ruddy, blood, or deep red-orange colouration with white-mottling -as in the [[Spanish dancer]] (”H. sanguineus”) or yellow-margined Spanish dancer,<ref name=”MALAQUIAS” /> a colouration that is inconsistent with the greyish purple of the Dolphin 1 animal.<ref name=”TONMO” /> Juvenile dancers are a translucent shade with purplish spotted accents,<ref name=”MALAQUIAS” /> more closely resembling the Dolphin 1 animal than their adult but still being incomparable to the animal’s solid colouration. The shape of the body is also a point of contention, as dancers possess a flat pill-shaped body<ref name=”MALAQUIAS” /> that is inconsistent with the tapered-ovular shape of the Dolphin 1 animal.<ref name=”TONMO” /> Upon presenting the photographs to a team of divers, one user in the original thread had concluded the Dolphin 1 animal to be a dancer based on their collective identification of the animal as such.<ref name=”TONMO” /> The user proposed that the “questing forward nose” along with its locomotion was indicative of characteristic swimming styles of dancers, though this conclusion received significant pushback from Dr. O’Shea and various other users.<ref name=”TONMO” /> Dancers swim in a very particular dorso-ventral undulating motion<ref name=”MALAQUIAS” /> that with the way that the movement of the animal was described. The skirt of the Dolphin 1 animal also fails to match the margins or skirts exhibited among dancers, as it was likely comprised of two appendages wrapped to , whereas in ”Hexabranchus” species, the margin is an unbroken skirt of membranous tissue that is often crumbled or crinkled when swimming. The photographs also do not present any rhinophores, which are characteristic of sea slugs and nudibranchs. Some users believed the animal to be inverted or upside down,<ref name=”TONMO” /> implying the conclusion that the rhinophores may have been obscured if it did possess any. Many users also claimed that the animal was far too big for a sea slug, as most dancers reach a maximum length of about 22cm (8.7in).<ref name=”MALAQUIAS” />
===Aplysia===
===Aplysia===
[[File:Aplysia brasiliana (mottled sea hare) (Sanibel Island, Florida, USA) 4 (24612315926).jpg|thumb|A [[Aplysia brasiliana|mottled sea hare]] (”Aplysia brasiliana”).]]”[[Aplysia]]” is a genus of sea hares part of the ”Aplusiidae” family that includes the mottled sea hare, a suggested identity for the Dolphin 1 animal.<ref name=”TONMO” /> Sea hares are morphologically disimilar to the animal, having pronounced wings ([[Parapodium|parapodia]]) which undulate in a similar manner to dancers when the sea hare is in motion,<ref name=”APLUSIIDAE“>{{cite web |last1=Beechey |first1=Des |title=Aplusiidae Intro – Sea Hares |url=https://seashellsofnsw.org.au/Aplysiidae/Pages/Aplysiidae_intro.htm |website=Seashells of New South Wales |access-date=7 February 2026}}</ref> differentiating it from the animal’s slow swimming style. Sea hares can range from as 10-750mm (0.4-29.5in)<ref name=”APLUSIIDAE” /> across all species, putting the Dolphin 1 animal in the appropriate size range to identify as a sea hare species. Unlike many large sea slugs, various sea hares are known to swim at the surface of water. Sea hares derive their colour from the diet of algae they consume, and are often mottled in colouration<ref name=”APLUSIIDAE” /> unlike the solid colouration of the Dolphin 1 animal.<ref name=”TONMO” /> The mottled sea hare was suggested as a potential identity for the animal in the thread despite the species’ very prominent parapodia, elongated body shape, and dingy yellowish brown or washed-out green colour, which are all features that are not consistent with the Dolphin 1 animal. Similarly to sea slugs, sea hares possess rhinophores, as well as additional head tentacles which are incredibly prominent and not present in the photographs of the Dolphin 1 animal.<ref name=”APLUSIIDAE” /> Lastly, sea hares possess flattish-shaped internal shells that are relatively obvious from the external anatomy, a trait that is once more not present in the animal.<ref name=”APLUSIIDAE” /> THis may potentially explain the melon-like structure on the animal’s body in one photo.
[[File:Aplysia brasiliana (mottled sea hare) (Sanibel Island, Florida, USA) 4 (24612315926).jpg|thumb|A [[Aplysia brasiliana|mottled sea hare]] (”Aplysia brasiliana”).]]”[[Aplysia]]” is a genus of sea hares part of the ”” family that includes the mottled sea hare, a suggested identity for the Dolphin 1 animal.<ref name=”TONMO” /> Sea hares are morphologically to the animal, having pronounced wings ([[Parapodium|parapodia]]) which undulate in a similar manner to dancers when the sea hare is in motion,<ref name=””>{{cite web |last1=Beechey |first1=Des |title= Intro – Sea Hares |url=https://seashellsofnsw.org.au/Aplysiidae/Pages/Aplysiidae_intro.htm |website=Seashells of New South Wales |access-date=7 February 2026}}</ref> differentiating it from the animal’s slow swimming style. Sea hares can range from as 10-750mm (0.4-29.5in)<ref name=”” /> across all species, putting the Dolphin 1 animal in the appropriate size range to identify as a sea hare species. Unlike many large sea slugs, various sea hares are known to swim at the surface of water. Sea hares derive their colour from the diet of algae they consume, and are often mottled in colouration<ref name=”” /> unlike the solid colouration of the Dolphin 1 animal.<ref name=”TONMO” /> The mottled sea hare was suggested as a potential identity for the animal in the thread despite the species’ very prominent parapodia, elongated body shape, and dingy yellowish brown or washed-out green colour, which are all features that are not consistent with the Dolphin 1 animal. Similarly to sea slugs, sea hares possess rhinophores, as well as additional head tentacles which are incredibly prominent and not present in the photographs of the Dolphin 1 animal.<ref name=”” /> Lastly, sea hares possess flattish-shaped internal shells that are relatively obvious from the external anatomy, a trait that is once more not present in the animal.<ref name=”” /> may potentially explain the melon-like structure on the animal’s body in one photo.
==External Links==
==External Links==
Unidentified marine animal
The Dolphin 1 animal, also referred to as Gwenith Penry’s blob, or simply mystery animal is an unidentified marine animal that was observed and photographed off the coast of South Africa in 2007. The animal most resembles a cephalopod in outward appearance.[1] It was observed by the crew of the Dolphin 1, and is often connoted in correlation to the vessel’s name. The scientific name, Hepatomares striata (roughly translating to ‘striped liver’ in Latin), was proposed in jest due to the species’ resemblance to a striped liver.[1]
The animal is membranous in appearance, with a rounded body that tapers towards the anterior edge of the body. Most intriguingly, the subject of the photos seems to have a ‘nose’ or proboscis at the anterior, which is most apparent in one photo but largely absent from the other three.[1] The body was estimated at 30-40cm (12-16in) long with a thickness of 5-10cm (4-6in) around the anterior end.[1] It possessed what has been referred to as a ‘skirt’ around the posterior end, likely comprised of two appendages wrapped around the posterior that meet at the tips rather than a single contiguous structure like the flap of a ray.[1] This skirt was estimated to be around 2-5cm (0.8-2in) thick.[1] The dorsum is entirely a greyish mauve colour and in some photos, the underside appears to potentially be a lighter cream (evident of countershading). The skirt is banded with white and a dark reddish orange, and the tip of the ‘nose’ is white. In one photo, two large divots (likely pores) and a vent are visible, as well as a ruddy orange colouration on the underbelly and behind the vent.[1] In one photo, it appears to potentially have a melon-like structure on its ‘head’ however, this may be air trapped in its mantle (if it is a cephalopod).[1]
Initial Sighting
The Dolphin 1 animal was observed and photographed at 9:30am (GMT+2) on the 27th of March, 2007 off the coast of South Africa as part of a tour by Ocean Safaris.[1] It was sighted on the Dolphin 1 vessel by a crew of 14 which included marine biologists Dr. Steve O’Shea and Dr. Gwenith Penry, the latter having photographed the four images of the animal by which it is most well known.[1]
The animal stayed at the surface, initially appearing about 30cm (12in) beneath the water before surfacing further and exposing some of its body.[1] It lifted its nose towards the vessel as if sensing if something was in front of it, potentially implying that the nose may be a sensory organ. This interaction was photographed.[1] The animal swam away after the initial sighting. It was suspected that it was propelling itself relatively slowly through the water by using vents in a similar manner to known squids and octopi. It moved with its nose leading.[1]
During the sighting, a pod of 200+ bottlenose dolphins was feeding nearby, however, neither the dolphins nor the animal interacted with one another.[1]
Reaction and Potential Identity
The photos of the Dolphin 1 animal were posted on the 6th of April, 2007 to cephalopod news forum/online magazine, Tonmo, by Dr. Steve O’Shea after gaining permission by photographer Dr. Gwenith Penry.[1] The thread, entitled; “Unknown Phylum. Any suggestions?” accumulated much attention from the community by both hobbyists and biologists alike due to the cryptic nature of the species. Theories of the animal’s identity ranged from it being a Tremoctopus (a genus comprised of blanket octopi species and the sole genus in its family, Tremoctopodidae), a dancing sea slug, a sea cucumber, sea hare, or even potentially a sharp-tailed sunfish (Masturus lanceolatus), jellyfish, or ray.[1] The prevailing notion however, is that it was a cephalopod, likely Tremoctopus. Despite this, the hypothesis that it was a species of dancing sea slug was also discussed, with one user claiming they presented the photo to a group of divers who agreed with the conclusion that the animal was a sea slug.[1]
Other explanations
Multiple non-animal explanations were given for the identity of the Dolphin 1 animal that do not refer to specific species. Some more outlandish explanations from the original thread posit that the creature was actually a detached dolphin placenta that appeared to move due to the current, or that the specimen was a result of formaldehyde contamination in offshore South Africa.[1] Dr. O’Shea himself stated that he believed the animal to be a vertebrate rather than an invertebrate, and that it was likely an unrecognised species of tail-less ray.[1]
Comparing the Dolphin 1 animal to known species
Tremoctopus
The Dolphin 1 animal is most frequently compared to a Tremoctopus, the blanket octopus genus. Blanket octopi exhibit very superficially similar morphology to the Dolphin 1 animal, possessing a gently elongated oval-shaped mantle, and two large primary arms that are often banded in a similar fashion to the skirt of the animal. The body of the blanket octopus is also a similar shape and similarly muscular.[2] Perhaps the most frequently used piece of evidence for the conclusion that the animal was a Tremoctopus is the superficial similarities between both, with both possessing a dull purple-grey dorsal colouration, a lighter ventral colouration[1] and similarly banded arms[1] (skirt in the Dolphin 1 animal). One photo of the Dolphin 1 animal also clearly exhibits aquiporous pores on its dorsal side,[1] a characteristic feature of the blanket octopus only seen elsewhere in the genus Ocythoe, but even in saying that, the species of this genus have their pores exclusively on the ventral side.[2] The pores on Tremoctopus are positioned between the eyes,[1] however, no discernable eyes are visible in any of the photos of the Dolphin 1 animal.[2]
This is not to say that the species is conclusively Tremoctopus, as a variety of difference exist between it and known members of the genus. For instance, blanket octopi are named in reference to the extravagant web-like “blanket” that stretches between the two main arms on the females[2] (Tremoctopus are incredibly sexually dimorphic) a feature which is definitively absent from the specimen in the photos.[1] It is possible that this individual may be a male, as male blanket octopi do not possess the blanket, however, male blanket octopi are far smaller than the reported size of the Dolphin 1 animal, ranging as small as 4.9mm (0.2in) in length.[2] It may simply have been tucking its other arms beneath its body as blanket octopi have been known to do while swimming, or have had its webbing torn off by predation.[1] It has been proposed also that the animal was sick or ill when the photos were taken, leading to its seemingly confused movements towards the vessel.[1] This behaviour is exhibited in countless other deep sea marine life, which often become disoriented and move towards shallower waters when dying or diseased. Tremoctopus also possess quite obvious large eyes, a greater number of arms, and a generally more conical shape and clearer demarkation between the head and mantle than the Dolphin 1 animal.[2] Blanket octopi also possess obvious suckers,[2] a trait absent from descriptions and photos of the Dolphin 1 animal.[1] It cannot be reliably declared that the animal did not possess them, as the positions in which it held its ‘arms’ potentially left any existing suckers obscured. The position by which the animal carried its ‘arms’ is also not consistent with Tremoctopus.[1][2] Tremoctopus also lacks the sensory ‘nose’ that the animal possesses, and while some claim in the original thread that the nose is just an extension of the mantle that appears nose-like due to its reflection against the water’s surface, Dr. O’Shea’s account of its independent movement from the body likely distinguishes it as a unique sensory structure.[1]
Hexabranchus
Hexabranchus is a mollusc genus that is comprised of the dancing sea slugs, large pelagic nudibranchs belonging to the family Hexabranchidae.[3] Dancing sea slugs are dissimilar in appearance to the Dolphin 1 animal excluding their similarly amorphous bodies. In terms of morphology, Hexabranchus species possess various traits which distinguish them from the specimen in the photographs, chiefly their rhinophores and far more pronounced skirts/margins around their mantles.[3] The vast majority of Hexabranchus species possess a ruddy, blood, or deep red-orange colouration with white-mottling -as in the Spanish dancer (H. sanguineus) or yellow-margined Spanish dancer,[3] a colouration that is completely inconsistent with the greyish purple of the Dolphin 1 animal.[1] Juvenile dancers are a translucent shade with purplish spotted accents,[3] more closely resembling the Dolphin 1 animal than their adult counterparts but still being incomparable to the animal’s solid colouration. The shape of the body is also a point of contention, as dancers possess a flat pill-shaped body[3] that is inconsistent with the tapered-ovular shape of the Dolphin 1 animal.[1] Upon presenting the photographs to a team of divers, one user in the original thread had concluded the Dolphin 1 animal to be a dancer based on their collective identification of the animal as such.[1] The user proposed that the “questing forward nose” along with its locomotion was indicative of characteristic swimming styles of dancers, though this conclusion received significant pushback from Dr. O’Shea and various other users.[1] Dancers swim in a very particular dorso-ventral undulating motion[3] that is inconsistent with the way that the movement of the animal was described. The skirt of the Dolphin 1 animal also fails to match the margins or skirts exhibited among dancers, as it was likely comprised of two appendages wrapped to meet, whereas in Hexabranchus species, the margin is an unbroken skirt of membranous tissue that is often crumbled or crinkled when swimming. The photographs also do not present any rhinophores, which are characteristic of sea slugs and nudibranchs. Some users believed the animal to be inverted or upside down,[1] implying the conclusion that the rhinophores may have been obscured if it did possess any. Many users also claimed that the animal was far too big for a sea slug, as most dancers reach a maximum length of about 22cm (8.7in).[3]
Aplysia
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Aplysia is a genus of sea hares part of the Aplysiidae family that includes the mottled sea hare, a suggested identity for the Dolphin 1 animal.[1] Sea hares are morphologically dissimilar to the animal, having pronounced wings (parapodia) which undulate in a similar manner to dancers when the sea hare is in motion,[4] differentiating it from the animal’s slow swimming style. Sea hares can range from as 10-750mm (0.4-29.5in)[4] across all species, putting the Dolphin 1 animal in the appropriate size range to identify as a sea hare species. Unlike many large sea slugs, various sea hares are known to swim at the surface of water. Sea hares derive their colour from the diet of algae they consume, and are often mottled in colouration[4] unlike the solid colouration of the Dolphin 1 animal.[1] The mottled sea hare was suggested as a potential identity for the animal in the thread despite the species’ very prominent parapodia, elongated body shape, and dingy yellowish brown or washed-out green colour, which are all features that are not consistent with the Dolphin 1 animal. Similarly to sea slugs, sea hares possess rhinophores, as well as additional head tentacles which are incredibly prominent and not present in the photographs of the Dolphin 1 animal.[4] Lastly, sea hares possess flattish-shaped internal shells that are relatively obvious from the external anatomy, a trait that is once more not present in the animal.[4] This may potentially explain the melon-like structure on the animal’s body in one photo.
External Links
References
- ^ a b c d e f g h i j k l m n o p q r s t u v w x y z aa ab ac ad ae af ag ah ai aj O’Shea, Steve. “Unknown Phylum. Any suggestions?”. Tonmo; The Octopus News Magazine Online. Deep Intuition, LLC. Retrieved 3 February 2026.
- ^ a b c d e f g h Thomas, Ronald F. (1977). “Systematics, Distribution, and Biology of Cephalopods of the Genus Tremoctopus (Octopoda: Tremoctopodidae)”. Bulletin of Marine Science. 27 (3). University of Miami – Rosenstiel School of Marine, Atmospheric & Earth Science. Retrieved 7 February 2026.
- ^ a b c d e f g Tibiriçá, Yara; Pola, Marta; Pittman, Cory; Gosliner, Terrence M.; Malaquias, Manuel A.; Cervera, Juan Lucas. “A Spanish dancer? No! A troupe of dancers: a review ofthe family Hexabranchidae Bergh, 1891 (Gastropoda, Heterobranchia, Nudibranchia)” (PDF). BioFund. Organisms Diversity and Evolution. Retrieved 7 February 2026.
- ^ a b c d e Beechey, Des. “Aplysiidae Intro – Sea Hares”. Seashells of New South Wales. Retrieved 7 February 2026.
