Laminatubus alvini ten Hove & Zibrowius, 1986

Rouse, Greg W. & Kupriyanova, Elena K., 2021, Laminatubus (Serpulidae, Annelida) from eastern Pacific hydrothermal vents and methane seeps, with description of two new species, Zootaxa 4915 (1), pp. 1-27 : 9-14

Laminatubus alvini ten Hove & Zibrowius, 1986

Figures 6–8

Laminatubus alvini ten Hove & Zibrowius, 1986 (description, line drawings, photo of tube, SEM of tube ultrastructure).

Laminatubus alvini .— Tunnicliffe (1992) (distribution Galapagos; East Pacific Rise: 13°N to 21°N); Desbruyères & Segonzac (1997) (diagnosis, figures, distribution Galapagos; East Pacific Rise: 21°N to 23°S); Mullineaux & Manahan (1998) (photo of colony in situ); Mullineaux et al. (1998) (recruitment at 9°50′N vent localities); Tunnicliffe et al. (1998) (biogeography: Guaymas vents 27°N, EPR at 21°N, Galapagos); Michelli et al. (2002) (9°50′N vent localities, ecology); Mullineaux et al. 2003 (9°50′N vent localities, succession); Desbruyères et al. (2006) (diagnosis, figures, distribution Galapagos; East Pacific Rise: 21°N to 23°S); Hey et al. (2006) (name and photo, 31°S and 32°S vent localities); Kupriyanova et al. (2006) (phylogeny, morphology and DNA; specimen from 31°S); Vinn et al. (2008) (tube ultrastructure and mineral composition; specimen from 9°N); ten Hove & Kupriyanova (2009) (diagnosis, SEM of chaetae from Galapagos Rift specimen); Mullineaux et al. (2009) (9°50′N vent localities, ecology; Goffredi et al. (2017) (DNA; two specimens from 23°N vent).

Material examined. AM: W.38421, 12°50’N, 103°57’W, Jeanie Site, 2010 Mescal cruise; W.49888, W.49956– 499562; W.49961 and W.38421 prepared for SEM; SAM: E5851 – E5879 ; SIO-BIC: A8568–8579 (see Table 1 for localities and measurement) . FMNH: 7045; SAM: 1717, E3531; SIO-BIC: A1654, A1658, A1660, A1662, A1668, A1670, A6158, A6327 (see Tables 1 and 2 for localities and GenBank accession numbers).

Description. TUBE: white opaque, semi-circular to circular in cross-section, without wide flaring peristomes, growth rings indistinct, attached to the substrate throughout its length. High, sharp, undulating longitudinal keel and distinct solid flattened attachment flange lacking alveoli present ( Fig. 6A, B , 7A ). External hyaline layer present.

RADIOLAR CROWN: Radioles not connected by inter-radiolar membrane ( Fig. 7C, D, E ), arranged into slightly ascending spiral of up to two whorls. Stylodes and radiolar eyes absent.

PEDUNCLE: smooth cylindrical (circular in cross-section), at least twice as thick as normal radioles ( Fig. 7 C–E), gradually merging into opercular ampulla, constriction absent ( Fig. 7B, C ). Small distal latero-dorsal “winglets” (flattened distal parts of the peduncle) or pair of lateral wings proximal to opercular ampulla absent. Peduncle inserted on left side of radiolar crown, below line of radioles ( Fig. 7C, D, E ).

OPERCULUM: bulbous to inverted conical proximal semi-transparent ampulla with distinct distal flattened to convex or pointed yellowish-brownish endplate covered with thickened cuticle ( Fig. 7 A–C).

COLLAR AND THORACIC MEMBRANES: collar high, covering bases of radiolar lobes, clearly trilobed, with longer and wider ventral lobe and smaller lateral ones ( Fig. 8A ) and entire edge ( Fig. 7D, E , 8A ), continuous with thoracic membranes as wide as thoracic tori, forming apron across anterior abdominal chaetigers ( Figs 7E , 8A ). Pairs of small, wart-like protuberances of collar chaetiger or elongated tonguelets between ventral and lateral collar parts absent.

THORAX: with collar chaetiger and five uncinigerous chaetigers ( Fig. 7E ), fascicle of collar chaetae separated from first uncinigerous chaetiger by a wide gap ( Fig. 8A ). Thoracic tori of approximately same length, gradually converging posteriorly, forming distinct triangular depression ( Fig. 8A, C ), but not touching each other medio-ventrally ( Fig. 8C ). Collar chaetae fascicle with limbate and poorly developed Spirobranchus - type chaetae or special chaetae absent altogether ( Fig. 8B ). Subsequent thoracic chaetae simple limbate, of two sizes, Apomatus chaetae absent ( Fig. 8D ). Uncini along entire thorax saw-shaped with 5–6 teeth, anterior fang simple pointed ( Fig. 8F ). Pair of prostomial eyes absent.

ABDOMEN: with up to 120 abdominal chaetigers. Achaetous anterior abdominal zone absent, distinct chaetae with long shaft (length similar to that of thoracic tori) starting from first abdominal segment. Tips of chaetae slightly bent and hollow, made of two rows of pointed teeth, thus true trumpet-shaped chaetae ( Fig. 8E ). Posterior capillary chaetae absent. Uncini saw-shaped anteriorly, with pointed fangs and 5–7 teeth, similar to thoracic ones; posterior-most uncini rasp-shaped with 3–4 rows of teeth, bluntly pointed fang and 7–8 teeth in profile view ( Fig. 8G ). Posterior glandular pad absent ( Fig. 7C ).

SIZE: length up to 29 mm (5.2–29 mm, Table 1 ). Radioles and operculum accounting for 2/5 of entire animal length.

COLOUR: white radiolar crown, white to yellowish body ( Fig. 7 B–E)

Distribution. Hydrothermal vents fields of East Pacific Rise, from 23°N to 38°S.

Reproduction. Two specimens from Alvin Dive 4091 released eggs 150 µm in diameter.

Remarks. Ten Hove and Zibrowius (1986) reported the distribution of L. alvini as “four areas with hydrothermal activity on the Galapagos Ridge and on the East Pacific Rise (approx. 1°N, 10°N, 13°N and 21°N), at depths of about 2500–2600 m ”, with the type locality being the Galapagos vents. Desbruyères & Segonzac (1997) and Desbruyères et al. (2006) reported distribution on the Galapagos vents and the East Pacific Rise from 21°N to 23°S. In their review Tunnicliffe et al. (1998) extended the distribution with their reporting of L. alvini from the sedimented Guaymas Basin vents at 27° N and Hey et al. (2006) reported the species further south on the East Pacific Rise from 31°– 32°S vent localities. We did not sequence L. alvini from the type locality, but did demonstrate that a single Laminatubus species, with very little genetic variability extends along the East Pacific Rise from 38°S to 23°N. We lacked specimens from the sedimented Guaymas Basin vents at 27°N, but samples from the nearby seeps in the Guaymas Basin turned out to be one of the new species described below.

Figures

FIGURE 6. Photos of Laminatubus alvini tubes, Alvin dive 4091. A—lateral view, B—dorsal view.

FIGURE 7. Photos of Laminatubus alvini specimens, Alvin dive 4094. A, B—variability of opercula, C—view of the thorax showing insertion of peduncle, D—dorsal view of an entire specimen removed from tube, E—lateral view of thorax.

FIGURE 8. SEM of Laminatubus alvini AM W.38421 body and chaetae.A—lateral view of thorax, B– collar chaetae, C—ventral view of thorax, D—chaetae of the second thoracic chaetiger, E—anterior abdominal chaetae, details of hollow tip, F—anterior thoracic uncini, G—anterior abdominal uncini.

Tables

TABLE 1. Specimens of Laminatubus alvini examined. Abbreviations: P—peduncle (=radiolar length), Th—thorax, A- abdomen, R—radioles. Length of complete specimens only is reported in the text.

Catalogue number	Length, mm	Alvin Dive	Coordinates	Depth, meters
AM W.49888	P7, Th2, A4	A4091	37°40.351S,110°52.617W	2236
AM W.49956	P5.5, Th1.5, A3	A4091	37°40.351S, 110°52.617W	2236
AM W.49957	P11, Th3.5, A-	A4091	37°40.351S, 110°52.617W	2236
AM W.49958	P12, Th2, A-	A4094	31°0939S, 111°55.919W	2237
AM W.49959	P11, Th3.5, A9.5	A4094	31°0939S, 111°55.919W	2237
AM W.49960	P11, Th2.5, A-	A4096	23°32.780S, 115°34.179W	2595
AM W.49961	P11, TH3.5, A8.5	A4096	23°32.780S, 115°34.179W	2595
AM W.49962	P11, Th2.5, A9	A4096	23°32.780S, 115°34.179W	2595
SAM E5851	P8, Th2.5, A-	A4096	23°32.780S, 115°34.179W	2595
SAM E5852	P8, Th3, A6	A4096	23°32.780S, 115°34.179W	2595
SAM E5853	P11, Th2, A-	A4096	23°32.780S, 115°34.179W	2595
SAM E5854	P7, Th2, A3	A4096	23°32.780S, 115°34.179W	2595
SAM E5855	P6.5, Th1.5, A3	A4091	37°40.351S, 110°52.617W	2236
SAM E5856	P-, Th2, A6.5	A4091	37°40.351S, 110°52.617W	2236
SAM E5857	P3, Th1, A2	A4091	37°40.351S, 110°52.617W	2236
SAM E5858	P3, Th0.7, A1.5	A4091	37°40.351S, 110°52.617W	2236
SAM E5859	P3, Th1.5, A-	A4091	37°40.351S, 110°52.617W	2236
SAM E5860	P6, Th1, A-	A4091	37°40.351S, 110°52.617W	2236
SAM E5861	P3, Th0.6, A-	A4091	37°40.351S, 110°52.617W	2236
SAM E5862	P6, Th-, A-	A4091	37°40.351S, 110°52.617W	2236
SAM E5863	P4, Th1, A2.5	A4091	37°40.351S, 110°52.617W	2236
SAM E5864	P6, Th1, A4	A4094	31°0939S, 111°55.919W	2237
SAM E5865	P6, Th2, A-	A4096	23°32.780S, 115°34.179W	2595
SAM E5866	P4, Th1.5, A2.5	A4096	23°32.780S, 115°34.179W	2595
SAM E5867	P9	A4096	23°32.780S, 115°34.179W	2595
SAM E5868	P -, Th1.5, A2.5	A4096	23°32.780S, 115°34.179W	2595
SAM E5869	P4.5, Th1, A3	A4096	23°32.780S, 115°34.179W	2595
SAM E5870	P11, Th3, A-	A4096	23°32.780S, 115°34.179W	2595
SAM E5871	R6, Th3, A-	A4096	23°32.780S, 115°34.179W	2595
SAM E5872	P6, Th1.5, A3	A4091	37°40.351S, 110°52.617W	2236
SAM E5873	P9, Th4, A-	A4096	23°32.780S, 115°34.179W	2595
SAM E5874	P9, Th2, A7	A4096	23°32.780S, 115°34.179W	2595
SAM E5875	P6.5, Th1.5, A4.5	A4096	23°32.780S, 115°34.179W	2595
SAM E5876	P6, Th1, A3	A4096	23°32.780S, 115°34.179W	2595
SAM E5877	P6.5, Th1, A3	A4096	23°32.780S, 115°34.179W	2595

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