Timarete hawaiensis Hartman 1956, new combination
Creators: name: Magalhães, Wagner F.
name: Bailey-Brock, Julie H.
Publisher: name: Zenodo
Year: 2010
Subjects: Biodiversity
Taxonomy
Animalia
Annelida
Polychaeta
Terebellida
Cirratulidae
Timarete
Timarete hawaiensis

description: Timarete hawaiensis (Hartman, 1956), new combination
Figures 1 (C, D, and F) and 4 (A–F)
Audouinia branchiata Treadwell, 1943: p. 1, Figs. 1–3.
Cirriformia hawaiensis Hartman, 1956: p. 293.
Cirriformia hawaiensis; Hartman, 1966: p. 226; Bailey-Brock, 1987: p. 371, plate 3.II. 3.c.
Material examined. Type material: Holotype (AMNH 3260), Pearl Harbor, Oahu, Hawaii, 1925, coll. A.E. Verrill. Non-type material: Pearl Harbor, Oahu, Hawaii, 1925, coll. A.E. Verrill (47, AMNH 3280); Hospital Point, Pearl Harbor, Oahu, Hawaii, 21°20΄56΄ 157°58΄0 7΄, 2m, Oct 1996, coll. R. DeFelice (2, USNM 1145382); Hull of Stoddart, Pearl Harbor, Oahu, Hawaii, 21°21΄20΄ 157°58΄11΄, Nov 2000, coll. R. Brock (3); Kaimana Beach on Gracilaria salicornia mats, Oahu, Hawaii, 21°15΄49΄ 157°49΄21΄, 9/04/09, coll. C. Moody (2), Kahuku, North shore of Oahu, Hawaii, removed from oyster shells, 12/27/97, 21°41΄22΄ 157°56΄35΄, coll. J.H. Bailey-Brock (4); Hanauma Bay, Keyhole, Oahu, Hawaii, 21°16΄11΄ 157°41΄41΄, from hard substrate, 8/ 17/99, coll. J.H. Bailey-Brock (3).
Redescription. Holotype 40 mm long, 2.2 mm wide for about 186 chaetigers. Other specimens 5–43 mm long, 0.8–2.8 mm wide for 66–182 chaetigers. Body rounded dorsally, flattened ventrally, narrower on posterior one-third in comparison with anterior end. Some specimens with shallow ventral groove on last chaetigers. Anterior and posterior ends with segments concertined. Distinct segments throughout. Color in alcohol yellow to tan; black spots on prostomium, peristomium and mid-body segments. Branchial and tentacular filaments pale yellow. Some specimens with darker area over dorsal surface including branchial filaments from posterior end of the body. Color in life not known.
Prostomium rounded, wider than long, without eyes (Fig. 4 A). Some specimens with row of pigment spots along anterior-ventral margin of peristomium and chaetigers 1–3. Peristomium formed by three annulations with first one dorsally inflated resembling dorsal crest.
Tentacular filaments in two widely separated groups, each dorsally located on chaetigers 3–4 in all specimens analyzed (Figs. 1 C and 4A, D), not size-dependent. Each patch with about 7–9 filaments arranged in two rows oblique to chaetigers 3 and 4, with more filaments on chaetiger 4. Branchial filaments first present on third peristomial annulation, one pair per segment; on chaetiger 1 positioned above notopodial ridge (Fig. 4 D). On chaetigers 10–18, branchial filaments shifted from near notopodium to mid-dorsum, with a larger distance than that between noto- and neuropodia from notopodium (Figs. 1 D and 4B). Dorsolateral bulge over notopodium on chaetigers 1–10 shifted to mid-dorsum on chaetiger 10–18. Branchial filaments numerous on anterior end and few to absent on posterior body. Shifting of branchial filaments not a sizedependent character (Fig. 5 C).
Parapodia well developed on anterior chaetigers forming distinct shoulder; this elongated forming lateral bulge where branchial filaments shift to mid-dorsum (Figs. 1 D and 4B). Noto- and neuropodium distinctly separated; notopodium lateral and neuropodium ventral throughout. Serrated capillary chaetae more abundant on anterior parapodia, with 6–8 capillaries (Fig. 4 F). Neuropodial acicular spines from chaetiger 8–19 while notoacicular spines from chaetigers 21–78; appearance of acicular spines size-dependent (Fig. 5 A). In several specimens, neuroacicular spines begin where branchial filaments shift dorsally above notopodia. Anterior acicular spines 3–4 per neuropodium, accompanied by 1–2 capillaries; fewer aciculars posteriorly, with 2–3 spines per neuropodium, rarely accompanied by capillaries. Anterior notoacicular spines 2–3 (rarely 4) per notopodium, with 1–2 acicular spines and rarely one capillary on far posterior chaetigers. Number of acicular spines on anterior and posterior noto- and neuropodia constant in relation to number of chaetigers. Neuroacicular spines curve distally, more robust than notoacicular spines (Fig. 4 C). Notoacicular spines pale yellow, straight, fragile, and mostly broken.
Pygidium with terminal anus (Fig. 4 E).
Methyl green staining pattern. Entire body including branchial and tentacular filaments staining slightly. Prostomium not staining while first peristomial annulation stained intensely. The second peristomial annulation not stained dorsally (Fig. 1 F). Notopodial and neuropodial ridges not stained.
Remarks. The transfer of Cirriformia hawaiensis to the genus Timarete was made based on the dorsal position of the branchial filaments on mid-body segments. This characteristic was previously reported in the descriptions by Treadwell (1943) and Hartman (1956, 1966).
Timarete punctata (Grube 1859) is a common species in Hawaii and differs from T. hawaiensis, new comb., by the body color. Timarete punctata is dark brown with black irregular spots throughout and tentacular filaments with black lateral stripes (Çinar 2007). Whereas, T. hawaiensis has dusky dark brown pigment only on the ventral surface of the peristomium; the branchial and tentacular filaments of alcohol preserved specimens are pale yellow. The tentacular filaments arise on chaetigers 3 and 4 on both species.
Treadwell (1943) and Hartman (1956) reported five or six neuroacicular spines in the holotype; however, none of the specimens examined, including the holotype, have more than four aciculars in the neuropodium. Timarete hawaiensis differs from its congeners by the presence of branchial filaments on the third peristomial annulation.
Biology. The specimens from the type-locality inhabit sponges and are found with Haplosyllis spongicola Grube (1855) and Ophiactis cf. modesta Brock 1888. Timarete hawaiensis reproduces both sexually and asexually by fission. Some specimens were found regenerating anterior and/or posterior ends. Several specimens had completely regenerated anterior ends that were pale in color that contrasted with the darker pigmentation of the rest of the body. In addition, mature females were found with eggs. Petersen (1999) also stated that other Timarete species reproduce by architomic fragmentation.
Some specimens from Paiko Lagoon, south coast of Oahu Island, Hawaii, 21°16΄58΄ 157°43΄29΄, identified by Dr. Olga Hartman as Cirriformia hawaiensis were observed in aquaria by Thomas (1973). He pointed out that this species does not construct burrows but occupies a vertical subsurface position in the sediment with feeding tentacles and a few branchiae protruding above the surface. Timarete hawaiensis inhabits the sediment surface layers to about 10 cm in depth but is more abundant in the upper 5 cm. The long branchiae protrude into the overlying water for respiration; the tentacles picking up detritus at the sediment water interface that is presumably ingested.
Distribution. The type-locality is Pearl Harbor, south shore of Oahu, Hawaii (Treadwell 1943). Additional specimens were found at Paiko Lagoon (Thomas 1973; Bailey-Brock 1987), Hanauma Bay, and Kaimana beach, south shore, and at Kahuku, north shore of Oahu, Hawaii. This distribution indicates that T. hawaiensis is endemic to Oahu, Hawaii.
description: Published as part of Magalhães, Wagner F. & Bailey-Brock, Julie H., 2010, Redescription of Cirriformia crassicollis (Kinberg, 1866) and Timarete hawaiensis (Hartman, 1956) new combination, (Polychaeta: Cirratulidae), endemic polychaetes to the Hawaiian Islands, pp. 53-62 in Zootaxa 2625 on pages 58-60, DOI: 10.5281/zenodo.198228