Skip to main content

Ruff sea scaleworm (Sthenolepis ruffi) and solitary sea scaleworm (Neoleanira solitaria) from 3000 meters sea depth

Ruff sea scaleworm (Sthenolepis ruffi) and solitary sea scaleworm (Neoleanira solitaria) from 3000 meters sea depth

NEWS - Two marine scaleworms (Sthenolepis, Sigalionidae) from depths of 2350–3221 meters off the coast of Northern California collected as part of a long-term monitoring survey at the San Francisco Deep-Ocean Dredged Material Disposal Site and a baseline study by the US Navy off the coast of Northern California are new species.

Ruff sea scaleworm (Sthenolepis ruffi) has long palps and tentacular cirri, an upper group of neurochaetae with long blades, and a lower group of neurochaetae with non-canaliculate blades. Solitary sea scaleworm (Neoleanira solitaria) stands out among members of the genus by having simple fusiform supracicular neurochaetae in the posterior segments.

S. fimbriarum (Hartman, 1939) and S. spargens (Fauchald, 1972) are found in the Gulf of California, but the two can be easily distinguished by the size of the median antennae and auricles, the type of neurochaetae, and the elytra. S. ruffi is eyeless, has smaller auricles, long median antennae, smooth elytra without fimbriae on the edges and canaliculate blades.

S. ruffin is more closely related to S. spargens, both are eyeless and have small auricles and canaliculate blades. However, S. ruffin has long palps up to 12 segments and short tentacular cirri, five times longer than the tentacular parapodia. S. ruffi and S. spargens have been found at depths of 2350-3400 m, while S. fimbriarum at 18.2 m.

Ruffin is named after the late Robert Eugene Ruff in recognition of his many efforts in deep-sea exploration and collection of marine invertebrates, especially polychaetes. He also performed the first identification of these specimens. The species name is a noun in the genitive case.

In the Eastern Pacific, only two species are N. racemosa (Fauchald, 1972) and N. areolata (McIntosh, 1885). Both are similar to N. solitaria, in having small auricles, long median antennae and rounded boot-shaped ventral ctenidia. However, they differ in the length of the appendages of the first anterior segment, the shape of the branchiae and the type of neurochaetae.

N. solitaria differs from N. areolata in having the dorsal cirri of segment 3 longer, ¼ longer than those in N. areolata. The main feature that distinguishes N. areolata from N. solitaria and from the rest of the Neoleanira is the presence of spur-like processes at the base of the branchiae of the median and posterior regions.

N. solitaria differs from N. racemosa in having longer median and lateral antennae, and longer dorsal cirri of segment 3. N. solitaria has a longer anterior appendage, median and lateral antennae are ¼ longer than those of N. racemosa and regarding the dorsal cirri of segment 3, N. solitaria is twice as long as those of N. racemosa.

Solitaria is a Latin singular feminine adjective meaning 'solitary' or 'alone'. The only specimen of N. solitaria was found after much sampling in an area where other sigalionid species are found. The name also refers to the presence of a solitary fusiform chaeta in the neuropodia of the posterior segment, a characteristic that makes this species unique.

Original research

Christopher Cruz-Gómez & James A. Blake (2024). Description of new species of deep water Sthenolepis Willey, 1905 and NeoleaniraPettibone, 1970 (Annelida, Sigalionidae) from off Northern California, with the redescription of Sthenolepis spargens Fauchald, 1972. Zootaxa 5507 (2): 224–244, DOI:10.11646/zootaxa.5507.2.2

Dlium theDlium
Labels:

Popular Posts

Javan broadhead planarian (Bipalium javanum)

Cacing palu or Javan broadhead planarian ( Bipalium javanum ) is a species of animal in Geoplanidae, hermaphrodite, living on the ground, predators, often called only hammerhead or broadhead or shovel worms because of wide heads and simple copulatory organs. B. javanum has a slim stature, up to 20 cm long, up to 0.5 cm wide, head wide up to 1 cm or less, small neck, widening in the middle and the back end is rounded, all black and shiny. Javan broadhead planarians walk above ground level by raising their heads and actively looking left, right and looking up using strong neck muscles. Move swiftly, track meander, climb to get through all obstacles or make a new path if the obstacle is too high. Cacing palu track and prey on earthworms and mollusks. They use muscles and sticky secretions to attach themselves to prey to lock in. The head and ends of the body are wrapped around and continue to close the body to stop prey reactions. They produce tetrodotoxins which are very strong...
Read more

Thomas Sutikna lives with Homo floresiensis

BLOG - On October 28, 2004, a paper was published in Nature describing the dwarf hominin we know today as Homo floresiensis that has shocked the world. The report changed the geographical landscape of early humans that previously stated that the Pleistocene Asia was only represented by two species, Homo erectus and Homo sapiens . The report titled "A new small-bodied hominin from the Late Pleistocene of Flores, Indonesia" written by Peter Brown and Mike J. Morwood from the University of New England with Thomas Sutikna, Raden Pandji Soejono, Jatmiko, E. Wahyu Saptomo and Rokus Awe Due from the National Archaeology Research Institute (ARKENAS), Indonesia, presents more diversity in the genus Homo. “Immediately, my fever vanished. I couldn’t sleep well that night. I couldn’t wait for sunrise. In the early morning we went to the site, and when we arrived in the cave, I didn’t say a thing because both my mind and heart couldn’t handle this incredible moment. I just went down...
Read more

Prof. Weiming Zhu ironwood (Xantolis weimingii) described with completely glabrous flower crowns

NEWS - Xantolis weimingii (Sapotaceae, Chrysophylloideae) is described from Yunnan, southwest China and can be easily distinguished from its relatives by the combination of densely covered plants with ferruginous arachnoid-lanate, oblong or obovate leaves and pendulous staminodes at the base. Xantolis Raf. 1838 (Sapotaceae, Chrysophylloideae) is a small genus of trees and shrubs containing about 14 species with a distribution from the eastern Himalayas to the Philippines in tropical Asia. The genus is morphologically characterized by distinct spines, a sharp anther appendage, lanceolate lobes on the calyx and corolla, and aristate staminodes. Molecular data suggest that the genus is sister to the entire subfamily Chrysophylloideae and is a very isolated and poorly understood genus. Specimens was first collected in the Luzhijiang Valley in August 2015, but only sterile or fruiting specimens were collected. In April 2022, a specimen with flowers was finally collected in Wadie, Yuanjiang...
Read more