The Red-Lipped Batfish

The Red-Lipped Batfish

Photo courtesy of Barry Peters

Ogcocephalus darwini, or the red-lipped batfish, is a Teleost fish in the family Ogcocephalidae, commonly referred to as the batfishes,¹⁰  and is “one of the terminal groups of the highly modified order Pediculati,” the group that contains the angler, also referred to as the Lophiiformes ⁵. Not much literature exists about this bizarre creature, but what there is provides plenty of information.

Range and Habitat

Endemic and confined to the Galapagos islands, O. darwini is named after Darwin’s most influential region of study ⁵. It was originally collected using “Galapagos bait nets,” ⁵ which are skimmed over the rocky, sandy bottoms of the ocean floor, meaning the fish inhabits depths between 3-76 meters ¹¹. Many of the specimens are found on the west coast if Isla Isabella and one was found on the east coast of Isla Fernandina, implying that the most populated region is between these two islands in reef areas. This area is affected by the Humboldt Current ⁵, a slow and shallow cold water current ¹³, and by upwelling, a marine process that brings nutrients to the surface ¹⁴. 

Physical Description:

This strange fish has many unique features, but one of the most prominent, the trait for which it is commonly named, is its bright red lips ⁹. This red or pink coloration can extend to the lower surface of the fish as well as the two dorsal stripes that trace along the fish’s body ⁵. Aside from this comical coloration, the O. darwini sports limb like appendages ⁹ formed by the pelvic and pectoral fins, and a horizontally protruding snout that is equally high as it is wide ⁵, with a horn with a few short hairs ¹². This horn also contains a fish-lure ¹² in a small cavity. It has fine, needle-like, villiform teeth, and the tongue is covered by dentate ² area partially divided by a groove ⁵. More generally, it has a flattened, disk shaped body, sandpaper-like skin, a fine, prickly but velvety, shagreen covering ⁵, 4 dorsal rays and 3 anal rays, and typically grows to around 25 cm ⁹.     

Behavior:

The red-lipped batfish acts as oddly as it looks. Although it is capable of an awkward, flailing, attempt at swimming, it tends to walk on the ocean floor with its modified foot-like fins instead of actually swimming ⁶. Not very much is known about how this strange creature functions, and one of the biggest points of mystery is what it does with the fish lure concealed in its snout. It is unknown whether this apparatus is used to attract prey or a mate, for sensory perception, or some other completely undiscovered function. Their reproduction is centered around pelagic ³ environments, meaning they mate and lay their eggs, which spawn pelagic larvae, in open waters. They are carnivores ¹² that feed primarily on mobile benthic worms, crustaceans like shrimp or crabs, and gastropods or bivalves. When their anatomy is considered, it is understandable that these fish are restricted in diet. Their limited mobility means they need easy to catch prey; their small size limits them to small targets; however, their sharp teeth enable them to crunch open shelled invertebrates, making their feeding habits a bit more functional. Not much research has gone into examining the behavior of the red-lipped batfish, but diving photographers have made some interesting observations. Eric Riesch ¹ tells that “finding batfish is often the hard part” due to their preference for habituating reef beds and ability to blend well with the sandy ocean floor. These fish are shy and “will try to turn away” when approached too quickly, so getting a good shot of them is tricky. The mysterious peculiarities of this bizarre fish doubtlessly elicit intrigue, so hopefully more research will be done in the near future to unravel the unknown.

Conservation Status:

Luckily for this weird little guy, he is in the conservation list of Least Concern ³ as of 2010. Due to its large depth range that spans into deeper water habitats, there are no real threats to O. darwini, and populations show no sign of any significant decline. It is also of no interest to the fishing industry, and poses absolutely no threat to humans ¹¹, meaning this fish sees no danger other than accidental netting from us. Although it is in the group of Least Concern, due to its habitat restriction to the Galapagos Islands ⁸, it is included under the shelter of the Galapagos Islands Marine Protected Area. The Galapagos Marine Reserve ⁴ was created a few decades back to shield the unique species that live on and around the Galapagos islands from the increasing human activity. In this protected area, El Nino is one of the most damaging issues. This phenomenon is caused by differences in water between the East and West areas of the Tropical Pacific, and cause devastating rains and local water temperature changes, causing many marine animals to die, leading to malnutrition in others ⁴. Although El Nino affects the area O. darwini inhabits, the species is able to evade its disastrous damage, most likely due to the depth range mentioned above. The red-lipped batfish basically has everything going in its favor in relation to conservation, which certainly makes up for strange path evolution has led it down.  

Evolutionary History:

O. darwini’s evolutionary history has not been mapped out, but the order to which it belongs, the Lophiiformes or anglerfish, and more specifically its suborder Ogcocephaloidei, the batfishes, have been extensively examined. Originally, Lophiiformes were thought to be primitive within the groups of higher teleosts, the group to which most modern fishes belong, having a common ancestry with the Batrachoidiformes, or toad fish. However, with the recent use of molecular phylogenetic studies, Lophiiformes were found to be “highly derived teleosts, deeply nested in one of the larger percomorph clades” ⁷ . Until the introduction of molecular research, lophiiform fishes’ pasts were unclear due to poor fossil representation. These recent advances have allowed scientists to move away from the use of the molecular clock and recalibrate their assessment to include multiple points of reference, including major events such as Gondwanian fragmentation. The entire tree was not deciphered in this study, but some significant information was obtained. The researchers determined that the order Lophiiformes is, in fact, monophyletic as others have described based on 6 complex synapomorphies. Further monophyly was determined for each of the 5 suborders, as well and the clade containing 4 out of 5 suborders (Ogcocephaloidei, Antennarioidei, Chaunacoidei, and Ceratoidei). Determining relations between fewer suborders is trickier, but researchers have almost conclusively determined that Ogcocephaloidei and Ceratoidei, the deep sea anglerfishes, comprise a monophyletic clade, bringing us closer to knowing what is going on with the odd little red-lipped batfish. 

References:

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"Dentate." Merriam-Webster. Merriam-Webster, n.d. Web. 24 Nov. 2014. ²

"Descriptions and Articles about the Galápagos Batfish (Ogcocephalus Darwini) - Encyclopedia of Life." Encyclopedia of Life. N.p., n.d. Web. 24 ³ 

"Dirección Del Parque Nacional Galápagos." Dirección Del Parque Nacional Galápagos. N.p., n.d. Web. 24 Nov. 2014. ⁴

Hubbs, Carl L. "Ogcocephalus Darwini, a New Batfish Endemic at the Galapagos Islands."Copeia 1958.3 (1958): n. pag. Jstor. Web. 24 Nov. 2014. ⁵

"NATURE | Shark Mountain | Red-lipped Batfish | PBS." YouTube. YouTube, n.d. Web. 24 Nov. 2014. ⁶

Miya, Masaki, Theodore W. Pietsch, James W. Orr, Rachel J. Arnold, Takashi P. Satoh, Andrew M. Shedlock, Hsuan-Ching Ho, Mitsuomi Shimazaki, Mamoru Yabe, and Mutsumi          Nishida. "Evolutionary History of Anglerfishes (Teleostei: Lophiiformes): A      Mitogenomic Perspective."BMC Evol Biol. 10.58 (2010): n. pag. 23 Feb. 2010. Web.          24 Nov. 2014. ⁷

"Ogcocephalus Darwini." (Batfish, Galápagos Batfish). N.p., n.d. Web. 24 Nov. 2014. ⁸

"Ogcocephalus Darwini." Discover Life. N.p., n.d. Web. 24 Nov. 2014. ⁹

"Ogcocephalus Darwini." ITIS Standard Report Page. ITIS, n.d. Web. 24 Nov. 2014. ¹⁰

"Ogcocephalus Darwini Summary Page." FishBase. N.p., n.d. Web. 24 Nov. 2014. ¹¹

"Smithsonian Tropical Research InstituteShorefishes or the Tropical Eastern Pacific Online Information System." SFTEP Online. N.p., n.d. Web. 24 Nov. 2014. ¹²

The Editors of Encyclopædia Britannica. "Peru Current." Encyclopedia Britannica Online. Encyclopedia Britannica, n.d. Web. 24 Nov. 2014. ¹³

"Upwelling." Encyclopedia Britannica Online. Encyclopedia Britannica, n.d. Web. 24 Nov. 2014. ¹⁴