Species New to Science's Journal

[Invertebrate • 2018] An Inordinate Fondness for Osedax (Siboglinidae: Annelida): Fourteen New Species of Bone Worms from California

Osedax jabba

Rouse, Goffredi, Johnson & Vrijenhoek, 2018

DOI: 10.11646/zootaxa.4377.4.1

Abstract

We incorporate DNA sequences from a comprehensive sampling of taxa to provide an updated phylogeny of Osedax and discuss the remarkable diversity of this clade of siboglinids. We formally describe 14 new species of Osedax from Monterey Bay, California, USA, raising the total number of properly named Osedax species to 25. These new species had formerly been recognized by informal names in various publications, and on GenBank. The descriptions document the occurrence of dwarf males in five of the new species. The distribution for the 19 species of Osedax known to occur in Monterey Bay across depths from 385 to 2898 meters and various bone substrates is documented. The exploitation of extant bird and marine turtle bones by Osedax is reported for the first time.

Key words: Siboglinidae, Annelida

FIGURE 9. Osedax jabba n. sp., previously Osedax ‘spiral’, sp.1 SBJ-2006.
C. Two specimens of Osedax jabba n. sp. at 2898 meters in November 2005. Two prominent red blood vessels are visible through the tube of each specimen and these indicate the trunk is occupying whole of tube and is coiled anteriorly. Trunk does not appear to emerge from tube.

Siboglinidae Caullery, 1914

Osedax Rouse, Goffredi & Vrijenhoek 2004

Remarks. This diagnosis is revised from that in Rouse et al. (2004) to accommodate the diversity of Osedax forms. These include Osedax jabba n. sp. where the females lack palps entirely and Osedax priapus where the males are not paedomorphic dwarfs, but also consume bone and have similar anatomy to females. Many Osedax species have palps that lack obvious pinnules. The dorsal placement of the oviduct reflects the reorientation of Osedax as reported in Huusgaard et al. (2012) and Worsaae et al. (2016).

FIGURE 2. Osedax sigridae n. sp., previously Osedax ‘green palp’.
A. View of cut surface of a cow femur deployed at 1820 meters in Monterey Canyon. Uncut surface of the bone has been heavily colonized by Osedax sigridae n. sp. Note greenishyellow color of the palps. B. Osedax sigridae n. sp. specimens in A. penetrated through outer surface of the cow bone and then expanded into the area beneath. This allowed for the whole outer layer of outer bone, and the Osedax, to be peeled away. Posterior ends (ovisacs) of multiple individuals are shown here. No major root structures extend from the ovisacs. C. Paratype of Osedax sigridae n. sp. (SIO-BIC A7810) with some bone surrounding the trunk. Oviduct is visible and pinnules of all four palps are oriented dorsally. D. Dorso-lateral view of holotype of Osedax sigridae n. sp. (SIO-BIC A7809) dissected from bone. Oviduct is not visible as it lies among the palps, which have pinnules oriented dorsally. Note greenish hue of palps. Green tissue surrounding part of the ovisac.

Osedax sigridae n. sp.

Distribution. Known from Monterey Bay, California from 1820 meters depth (Table 2). It has been found in whale and cow bones.

Etymology. This species is named (noun in the genitive case) for Sigrid Katz, whose Ph.D. project involved detailed study of the anatomy of this species (Katz et al. 2010; Katz et al. 2011).

Osedax talkovici n. sp.

Distribution. Known from Monterey Bay, California from 633 to 1018 meters depth (Table 2). It has been found in whale, elephant seal, cow, turkey, turtle and teleost bones.

Etymology. This species is named (noun in the genitive case) for Mark Talkovic, Senior ROV pilot for MBARI, who collected many bones containing Osedax over the years.

Osedax tiburon n. sp.

Distribution. Known from Monterey Bay, California from 1820 meters depth (Table 2).

Etymology. This species is named (noun in apposition) for the ROV Tiburon, which was used to collect the first Osedax specimens.

Osedax ventana n. sp.

Distribution. Known from Monterey Bay, California from 2898 meters depth (Table 2). It has only been found in experimentally deployed cow bones.

Etymology. This species is named (noun in apposition) for the ROV Ventana, which was used to collect many Osedax specimens.

Osedax docricketts n. sp.

Distribution. Known from Monterey Bay, California from 1820 meters depth, and Sagami Bay, Japan (Table 2). It has been found living on cow and whale bones.

Etymology. This species is named (noun in apposition) for the ROV Doc Ricketts, which was used to collect many Osedax specimens.

Osedax westernflyer n. sp.

Distribution. Known from Monterey Bay, California from 1820 meters depth and Sagami, Bay Japan (Table 2). It has been found in cow and whale bones.

Etymology. This species is named (noun in apposition) for the Research Vessel Western Flyer, which has been critical to Osedax studies.

Osedax knutei n. sp.

Distribution. Known from Monterey Bay, California from 1018 to 2898 meters depth (Table 2). It has been found in whale, cow, turkey and teleost bones.

Etymology. This species is named (noun in the genitive case) for Knute Brekke, Chief ROV pilot for MBARI, who expertly collected many bones and Osedax over the years.

Osedax lonnyi n. sp.

Distribution. Known from Monterey Bay, California from 2898 meters depth (Table 2). It has only been found in a whale bone fragment, adjacent to the main skeleton.

Etymology. This species is named (noun in the genitive case) for Lonny Lundsten, Senior Research Technician at MBARI, for his enthusiasm and assistance on many Osedax expeditions.

Osedax ryderi n. sp.

Distribution. Known from Monterey Bay, California from 2898 meters depth (Table 2). It has been found in whale and turtle bones.

Etymology. This species is named (noun in the genitive case) for Ryder Williams, for his generosity in sharing his mom for our research efforts.

FIGURE 9. Osedax jabba n. sp., previously Osedax ‘spiral’, sp.1 SBJ-2006.
A. Anterior end of whale fall ‘Ruby’ at 2898 meters in September 2004. Baleen is prominent on surface of sediment in foreground with tubes (white arrows) of large chaetopterid annelid Phyllochaetopterus gigas (see Nishi & Rouse 2014). Little bone obvious on sediment surface. Background has a cluster of more than 10 Osedax jabba n. sp. (black arrow) with their tubes coming directly out of the sediment. B. Cluster of more the 10 (black arrows) Osedax jabba n. sp. at 2898 meters in November 2004. No obvious bone on the sediment surface. C. Two specimens of Osedax jabba n. sp. at 2898 meters in November 2005. Two prominent red blood vessels are visible through the tube of each specimen and these indicate the trunk is occupying whole of tube and is coiled anteriorly. Trunk does not appear to emerge from tube. D. Lateral view of an Osedax jabba n. sp. specimen emerging from sediment surface, though adjacent to a piece of bone, at 2898 meters in January 2006. Blood vessels are visible, indicating trunk is filling tube.

Osedax jabba n. sp.

Distribution. Known only from Monterey Bay, California from 2898 meters depth (Table 2). Osedax jabba n. sp. was only found in sediment surrounding the natural whale fall at this depth (Figs 9A-D). Most specimens were at the head end of the whale, near a mass of baleen (Fig. 9A). All had bone fragments attached to the root mass buried in the sediment.

Etymology. The trunk of the new species is reminiscent of the tail of the mythical creature Jabba the Hutt from the Star Wars franchise (Sansweet 1998). We name the new species (noun in apposition) in its honor.

Osedax lehmani n. sp.

Distribution. Known from Monterey Bay, California only from 349 meters depth (Table 2). It has been found in whale and cow bones.

Etymology. This species is named (noun in the genitive case) in memory of Alan George Lehman, father of Ellen Lehman, in recognition of her long and continued support of the Scripps Oceanographic Collections.

Osedax packardorum n. sp.

Distribution. Known from Monterey Bay, California at 349, 633, and 1018 meters depths (Table 2). Found in whale and cow bones.

Etymology. This species is named (noun in the genitive case) in honor of the Packard family whose foundation supports MBARI and enabled the discovery of all of the Osedax species in California.

Osedax randyi n. sp.

Distribution. Known from Monterey Bay, California from 1018 meters depth, and from Sagami Bay, Japan (Table 2). It has been found in whale and cow bones.

Etymology. This species is named (noun in the genitive case) in honor of Randy Prickett, Senior ROV pilot for MBARI, who collected many bones and Osedax over the years.

Osedax bryani n. sp.

Distribution. Known from Monterey Bay, California from 1820 meters depth in whale bone.

Etymology. This species is named (noun in the genitive case) in honor of Bryan Touryan-Schaefer, ROV Pilot/ Technician for MBARI, who collected many bones with Osedax over the years.

TABLE 5. Colonization (x, axis x1 lower) of fish, turtle, turkey, fur seal, elephant seal, whale, pig, and cow on lower x axis, with known depth ranges on upper x axis (●, axis x2, upper) by Osedax species.

Greg W. Rouse, Shana K. Goffredi, Shannon B. Johnson and Robert C. Vrijenhoek. 2018. An Inordinate Fondness for Osedax (Siboglinidae: Annelida): Fourteen New Species of Bone Worms from California. Zootaxa. 4377(4); 451–489. DOI: 10.11646/zootaxa.4377.4.1