Teuthidodrilus
| Teuthidodrilus | |
|---|---|
Scientific classification 
| |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Annelida |
| Clade: | Pleistoannelida |
| Clade: | Sedentaria |
| Order: | Terebellida |
| Family: | Acrocirridae |
| Genus: | Teuthidodrilus Osborn, Madin & Rouse, 2011 |
| Species: | T. samae
|
| Binomial name | |
| Teuthidodrilus samae Osborn, Madin & Rouse, 2011
| |
Teuthidodrilus samae, dubbed as the squidworm, is a species of acrocirrid marine annelid worms. It is a detritivore and can grow to about 9 cm (3.5 in) in length and 1 cm (0.39 in) in width. It is named for the squid-like appendages emerging from its head. It was discovered in 2007 in the deep benthopelagic zone the Celebes Sea, near the Tawi-Tawi islands of the Philippines. It is the only species in the genus Teuthidodrilus. It is one of the two known genera of acrocirrids that have evolved a a free-swimming habit.[1][2]
Discovery
Teuthidodrilus samae was discovered in the 2007 "Exploring the Inner Space of the Celebes Sea" expedition by the remotely operated underwater vehicle Global Explorer ROV operated from the Philippine research vessel BRP Hydrographer Presbitero. Seven specimens were observed and collected from the deep-water column of the seafloor) of the Celebes Sea near the Tawi-Tawi islands of the Philippines. This area is part of the Coral Triangle, a location known for its increased biodiversity. The specimens were recovered at depths ranging from 2,039 to 2,912 m (6,690 to 9,554 ft), all within the demersal zone of around 100 m (330 ft) from the seafloor.[1][3]
Taxonomy
Teuthidodrilus samae is the only species classified in the genus Teuthidodrilus. It belongs to the family Acrocirridae of the class Polychaeta in the phylum Annelida. A similar undescribed and uncollected specimen observed from off western India by the Hercules 7 ROV in 2004 may represent a second species in the genus.[1]
The generic name comes from Greek for "squid worm", while the specific name is in honor of the Sama people of the Tawi-Tawi islands.[2] The holotype is deposited in the National Museum of the Philippines.[1]
Physical characteristics
The collected specimens ranged in size from 2 to 9.4 cm (0.79 to 3.70 in) in body length. The holotype has a body width of around 1 cm (0.39 in). Adults are light brown when alive, becoming light black in color when preserved. Juveniles are almost transparent.[1]
The body is divided into 25 segments (chaetigers) with pairs of large flattened paddle-shaped notopodia, around 15 mm (0.59 in) in length. Each notopodium has greater than 50 chaetae (bristles) arranged into a fin-like shape, except the first segment which has less than 10. Alongside the notopodia are pairs of neuropodia, each with around 2 to 4 chaetae.[1][4]
The head segment (prostomium) supports five pairs of long appendages. Four pairs of appendages are sensory and breathing organs (branchiae) at least 68 mm (2.7 in) in length. They are arranged along the upper and side ridges of the head, arising from the pair of feather-like nuchal organs which analyze chemical signals in the sea. The fifth pair of appendages are grooved and coiled feeding palps arising from below the mouth, which is located in the front-bottom corner of the head.[1]
Their internal anatomy, which is relatively visible from the outside since their outer body is semi-transparent, contains a heart, gut which forms loops, circulatory system with large efferent and afferent vessels leading to its gills. It also has give pairs of nephridia, which are organs similar to the kidney responsible for osmoregulation and expression. The female reproductive system consists of many spherical clusters of differently sized ova.[1]
Behavioral characteristics
Not much is known of this creature’s behavior other that it has the ability to swim with proficiency using two of its thin, paddle-like tentacles as well as its bristles that run across both faces of its body. It is categorized as a suspension eater since it consumes marine snow, which consists of pieces from animals, plants, feces and other organic materials that precipitate from the higher parts of the ocean towards the abyss.[1][5]
In total, sixteen specimens were observed and seven were collected within just a few dives suggesting that this animal is a common member of the deep benthopelagic community of the Celebes Sea basin.[1]
References
- ^ a b c d e f g h i j Osborn, Karen J.; Madin, Laurence P.; Rouse, Greg W. (2010). "The remarkable squidworm is an example of discoveries that await in deep-pelagic habitats". Biology Letters. 7 (3): 449–453. doi:10.1098/rsbl.2010.0923. PMID 21106571.
- ^ a b Watson, Traci (26 November 2010). ""Flamboyant" New Squid Worm Surprises, Delights Experts". National Geographic. Retrieved 17 October 2019.
- ^ "Exploring the Inner Space of the Celebes Sea 2007: September 27 – October 16, 2007". Ocean Explorer. National Oceanic and Atmospheric Administration (NOAA). Retrieved 17 October 2019.
- ^ Sample, Ian (24 November 2010). "'Squid worm' emerges from the deep". The Guardian. Retrieved 17 October 2019.
- ^ Choi, Charles Q. (24 November 2010). "Bizarre Squidworm Discovered". Inside Science. Retrieved 17 October 2019.