Farrea schulzei, Reiswig, 2018

Reiswig, Henry M., 2018, Four new species of Hexactinellida (Porifera) and a name replacement from the NE Pacific, Zootaxa 4466 (1), pp. 124-151 : 131-137

Farrea schulzei nomen nov.

( Figs 5 & 6 , Table 3)

Synonymy:

Farrea aculeata Bowerbank l875: 561, Pl 57: 1; Schulze 1887: 271; 1904:141; Lopes et al. 2011:178.

Farrea aculeata Schulze 1899: 69 , Pl. 15: 3-4.

Material examined. Type material: Farrea aculeata Schulze, 1899 , USNM 0 7549, USFCS Albatross Stn. 3071, 28 June 1889, off Sea Lion Rock , Washington State, USA, 47.48°, 125.56°W, 1161 m., two fragments, one now wet, one dry.

Non-Type material: CAS 218812, ROV Hercules from EV Nautilus , dive H1566, 26 Aug 2016, Wreck of USS Independence, side of midship gun turret, off Farallones Is., Farallones Sanctuary, San Francisco, California, U.S.A., 37.4776°N, 123.1346632°W, 805.8 m, fragment fixed 95% ethanol.

Not seen: MCZ IZ 141496, data as above, fragment.

Species diagnosis. Farrea with microspined pentactine dermalia and atrialia which are indistinguishable. Clavules are all anchorate and atrial, bearing few (0-10) shaft claws similar in size and form to the head claws. Large uncinates occur in two length classes. Microscleres are smooth oxyhexasters with equal primary and secondary ray lengths varying to hemioxyhexasters and rare oxyhexactins.

Description. Body form of the holotype described and figured as Farrea aculeata by Schulze (1899) consists of two apple-size pieces of anastomosing tubes, one with rather uniform finger-size tubes and the other as a cuplike form with terminal openings of several cm in diameter. The following description is restricted to the new specimen collected from the wreck of USS Independence. The body ( Fig. 5A ) is a pendant mass of branching and anastomosing tubes with widened outer apertures. Only a fragment consisting of a terminal tube and attached branch point ( Fig. 5B ) was available to the author for description. Tubes in the main body were not available for direct examination but their diameter can be assumed to be that of the smaller terminal tube openings, approximately 1.6 cm. Terminal tube diameters measured from in situ and laboratory images and the subsamples are 1.6– 2.8 –5.2 (n = 34) cm. Wall thickness is 0.78– 0.91 –1.10 (n = 4) mm. The dictyonal framework ( Fig. 5C and Table 3) is farreoid, being a single layer thick from the growing edge ( Fig. 5D ) to the lower end of the fragment. Meshes are rectangular; polyaxial longitudinal strands are pervasive and lateral beams are biaxial. Spurs are long thin rays, ~50% rough and ending in rounded or sharp tips, that curve evenly on both sides of the framework toward the osculum ( Fig. 5E ). Lattices of rough pentactins cover both inhalant and exhalant wall surfaces. In the whole-mounted wall, thick-rayed anchorate clavules are present only on the atrial surface ( Fig. 5F arrow heads), and there only in patches. The entire specimen measured from laser scales on in situ images was 53.3 cm long by 20.0 cm wide. Color in life was white; preserved it is light beige. Distribution of the species is known from N Washington State to N California at a depth of 805–1161 m.

Megascleres (for measurements see Table 3) consist of pentactine and a few paratetractine dermalia and atrialia, anchorate clavules and uncinates. Dermalia ( Fig. 6A ) are rough pentactins and rare paratetractins with rounded or sharp tangential ray tips and sharp proximal ray tips. Atrialia ( Fig. 6B ) are similar but overall slightly thinner. Clavules ( Fig. 6C ) occur only on the atrial side and are anchorate in two extreme forms. Since a complete series of intermediates occur, they are considered to be a developmental series and are treated here as a single category. The common form is the large one (> 350 µm length) with 6– 7 –9 (n = 20) thick, bluntly-pointed head claws and 2– 4 –7 (n = 41) similar shaft claws. The uncommon smaller form (<350 µm length) has 5–8 thin sharp head claws and few (0–3) shaft claws. Both forms are entirely rough and terminate in a parabolic tip on the shaft. Uncinates ( Fig. 6D ) occur in two distinct size classes by frequency analysis; a larger class with mean length of 3.37 mm and a smaller class with mean length of 1.32 mm. Both have well developed brackets and barbs.

n.a. = not available due to breakage; n.p. = not present; * = dermalia and atrialia not separable in preparations.

Microscleres (for measurements see Table 3) are hemioxyhexasters (55%) and full oxyhexasters (45%); no oxyhexactins were encountered in LM spicule counts but one was found on the SEM filter so they do occur. Oxyhexasters ( Fig. 6E ) and hemioxyhexasters ( Fig. 6F ) are similar in being entirely smooth and having primary rays slightly longer than secondary rays. Secondary ray per primary ray number 1– 3 –5. Secondary ray tips are commonly curved in a slight hook. The single oxyhexactin seen ( Fig. 6G ) has distinct swellings where primary and secondary parts of the rays meet. The spicule is also entirely smooth and has one ray tip slightly curved.

Remarks. Among the 46 known valid species of the genus Farrea , the new specimen from the Farallones Sanctuary conforms with only the preoccupied species Farrea aculeata Schulze, 1899 , from N Washington State, USA. Comparison with our measurements of the type of Schulze’s Farrea aculeata ( Table 3) shows spicule types are similar in form but some differences are attributable to differences in maturity and method of collection of the two specimens; the type is from an older part while the Farallones specimen was only available from a young distal tube. In the type, spurs are worn off the framework and dermal and atrial pentactins are displaced and not confidently separable; small oxyhexactins are extremely abundant both fused to the framework beams and as free spicules; breakage of larger uncinates and clavules are presumed to be responsible for the lack of data for uncinate 1 and bias of clavule data towards shorter lengths. Measurements of microscleres are almost identical.

Schulze, however, erred in naming the N Washington sponge as F. aculeata , a name already occupied by F. aculeata Bowerbank, 1875 and thus forming a junior homonym. Schulze was well aware of Bowerbank’s use of the name for a species which originated from an uncertain location (West Indies?), lacked free spicules and was considered then, and still now, as unrecognizable ( Lopes et al. 2011, van Soest et al. 2018). Here we designate a replacement of the preoccupied name, F. aculeata Schulze, 1899 , with a new combination formed, by convention, after the original describer, as Farrea schulzei n. nov.

Figures

FIGURE 5. Farrea schulzei n. nom., body. A. Encircled specimen in situ on USS Independence during collection by ROV. B. Terminal tubular element made available for inspection. C. One layer framework at mid-level of tube in B. D. Framework at growing edge showing growth of longitudinal strands before addition of dictyonalia. E. Oblique view of framework showing both internal and external spurs curved downstream towards the osculum. F. View of atrial surface of whole mount with arrowheads marking four of the anchorate clavules occurring only on this side.

FIGURE 6. Farrea schulzei n. nom., spicules. A. Dermalia, pentactin and paratetractin and closeups of tangential and proximal ray ends. B. Atrialia, pentactin and paratetractin with closeups of ray ends. C. Anchorate clavules, two whole and enlarged ends. D. Uncinate, whole and enlarged middle segment. E. Oxyhexaster with enlarged secondary ray end. F. Hemioxyhexaster. G. Oxyhexactin.