<i>Bathydorus laniger</i> and <i>Docosaccus maculatus</i> (Lyssacinosida; Hexactinellida): Two new species of glass sponge from the abyssal eastern North Pacific Ocean

Abstract

Two new species of glass sponge were discovered from the abyssal plain 200 km west of the coast of California (Station M). The sponges have similar gross morphology-an unusual plate-like form with basalia stilting the body above soft abyssal sediments. Bathydorus laniger sp. n. differs from its congeners by the presence of dermal and atrial stauractins; it is also supported by smooth hypodermal pentactins and hypoatrial hexactins. Microscleres include oxyhexasters and oxyhemihexasters. Docosaccus maculatus sp. n. contains large hexactins (>1 cm), characteristic of the genus. Megascleres include dermal hexactins, atrial pentactins, and choanosomal hexactins and diactins. Microscleres include oxytipped hemihexasters and floricomes. Several features serve to differentiate this species from its only known congener.

Benthic megafauna of the western Clarion-Clipperton Zone, Pacific Ocean

“…Remarks. External morphological characters are concordant with the description of D. maculatus (Kahn et al 2013). However, sequences for the 16S and COI genes from the holotype are 2.4% and 3.9% divergent (K2P distance), respectively, from the western CCZ specimen.…”

“…Sequences from 18S and 28S do not match to sequences from D. maculatus. The species was described from Station M, off California, in the Pacific Ocean at depths of 3,953-4,000 m, but the genus was originally thought to be restricted to Antarctica (Kahn et al 2013). This species has been recorded in the CCZ, in the eastern IFREMER contract area and in APEI 3, from 4905-4998 m depth (Kersken et al 2019).…”

Rossellid glass sponges (Porifera, Hexactinellida) from New Zealand waters, with description of one new genus and six new species

“…This New Zealand specimen, NIWA 126338, is entirely consistent with the diagnosis of Bathydorus and is assigned there. Each of the known species of the genus differ from this specimen in the following characters: Bathydorus echinus Koltun, 1967 has prostal pentactins in addition to diactins, and dermalia as mainly pentactins; B. fimbriatus Schulze, 1886 has prostalia including pentactins as marginalia only, and no pinular atrialia; B. laevis laevis Schulze, 1886 has no prostalia lateralia and no pinular atrialia; B. laevis pseudospinosus Tabachnick & Menshenina, 2013 has some large choanosomal or prostal hexactins and smaller oxyhexasters to only 100 µm diameter; B. laninger Kahn, Geller, Reiswig & Smith Jr., 2013 has a flat body form and no prostalia on the atrial (upper) surface; B. servatus Topsent, 1927 has no prostal diactins, and dermalia as stauractins and diactins; B. spinosissimus Lendenfeld, 1915 has choanosomal hexactins, and oxyhexasters with longer primary rays (4-12 µm); in the original description of B. spinosus Schulze, 1886, there is no mention of hypodermal pentactins; although Tabachnick and Menshenina (2013) include these, they fail to certify that they are present in the holotype; this species also has wavy secondary rays on the oxyhexasters; B. uncifer Schulze, 1899 has smooth dermal and atrial surfaces, and dermalia as mainly pentactins and stauractins. These differences are sufficient to conclude that the new form is a new species, here designated as Bathydorus poculum sp.…”

“…Atrialia are hexactins or stauractins. Microscleres are combinations of oxyoidal hexasters, hemihexasters, and hexactins; lacking pappocomes (fromKahn et al 2013).…”

Spatial and temporal variation in sponge spicule patches at Station M, northeast Pacific

“…1 a) and Docosaccus maculatus (Hexactinellida: Euplectellidae). Both sponges have very similar gross morphology: a plate-like form with basalia, which stilt the body a few centimeters above the seafloor (Kahn et al 2013 ). Using towed camera-sled images, Kahn et al ( 2012 ) found that both of these plate sponge species displayed inter-annual variations in density and average body size between 1989 and 2005.…”