Cold Biosilicification in Metazoan: Psychrophilic Glass Sponges

Numerous species of sponges (Porifera) habituate cold waters, including Antarctic seas. Silica-based skeletal structures, including spicules and skeletal frameworks, of representatives from both Demospongiae and Hexactinellida taxons arise due to biosilicification processes. The mechanism of this special biomineralization under psychrophilic conditions remains unknown. In this chapter, the psychrophilic problem is discussed as it pertains to different aspects of the life cycle of hexactinellid sponges. New data on the vertical distribution of Hexactinellida which proves the previous analogous investigations are given, as well as new interpretation of their mortal process. A new type of deep-sea reef construction of hexactinellid sponge Sarostegia oculata is described for the first time

A new genus and species of deep-sea glass sponge (Porifera, Hexactinellida, Aulocalycidae) from the Indian Ocean

New hexactinellid sponges were collected from 2589 m depth on the Carlsberg Ridge in the Indian Ocean during deep-sea dredging. All fragments belong to a new genus and species, Indiella gen. n. ridgenensis sp. n., a representative of the family Aulocalycidae described here. The peculiar features of this sponge, not described earlier for other Aulocalycidae, are: longitudinal strands present in several layers and epirhyses channelization

Aspidoscopulia bisymmetrica Tabachnick, Menshenina, Pisera & Ehrlich, 2011, sp. n.

Aspidoscopulia bisymmetrica sp. n. (Figures 1, 5– 10; Tables 2–3) Holotype. MNHN fr 546 (Fig. 5 C), Off Loyalty Islands (Fig. 1): Biogeocal, R.V. ‘Coriolis’, stn. DW 290, 20° 36.91 ’ S, 167 ° 3.34 ’ E, 920 – 760 m. Paratypes. MNHN fr 534, 535, 536, 537, 538, 543, same to the holotype location. Off Loyalty Islands: Biogeocal, R.V. ‘Coriolis’, stn. CP 297, 20° 38.64 ’ S 167 ° 10.77 ’ E, 1230–1240 m: MNHN fr 494. Musorstom 6, R.V. ‘Alis’, stn. CP 466, 21° 5.25 ’ S, 167 ° 32.2 ’ E, 540 m: MNHN p 1219. Stn. DW 488, 20° 49.2 ’ S 167 ° 6.44 ’ E, 800 m: MNHN p 3701. Off New Caledonia (Fig. 1): Biocal, R.V. ‘Jean Charcot’, stn. DW 80, 20° 31.69 ’– 31.86 ’ S, 166 ° 48.35 ’– 48.59 ’ E, 900–980 m: MNHN p 61. Halipro - 2, R.V. ‘Zoneco’, stn. BT 0 52, 25° 21.45 ’ S, 168 ° 16.94 ’ E, 810–1172 m: MNHN p 5019. Stn. BT 0 63, 24° 39.72 ’ S 168 ° 41.82 ’ E, 782–1100 m: MNHN p 5020. Musorstom 4, R.V. ‘Vauban’, stn. CP 199, 18° 50 ’ S, 163 ° 14.5 ’ E, 600 m: MNHN p 3744. Volsmar, R.V. ‘Alice’, stn. DW 4, 22° 24.7 ’– 22.4 ’ S, 171 ° 49 ’– 49.1 ’ E, 825–850 m: MNHN p 3732, p 3733, p 3734, p 3735. Off Wallis and Futuna Islands (Fig. 1): Musorstom 7, stn. CP 551, 12° 15.3 ’ S, 177 ° 28.1 ’ W, 791–795 m: MNHN p 3674. Stn. CP 592, 12° 32.4 ’ S, 174 ° 22 ’ W, 775 – 730 m: MNHN p 1142. Stn. DW 637, 13° 37 ’ S, 179 ° 56 ’ W, 820–830 m: MNHN p 6123. Norfolk Ridge (Fig. 1): Norfolk II, stn. 2053, 23.661 ° S, 168.260 ° E, 67–708 m: ZPAL Pf. 22 /wa 75. Stn. 2054, 23.660 ° S 168.253 ° E, 736–800 m: ZPAL Pf. 22 /wa 115, wa 117. Stn. 2055, 23.654 ° S 168.274 ° E, 900–950 m: ZPAL Pf. 22 /wa 70, wa 71, wa 72, wa 73. Stn. 2065, 25.261 ° S 168.927 ° E, 750–800 m: ZPAL Pf. 22 /wa 86. Etymology. The name refers to the bilateral symmetry of lateral branches, which arise from the main stem of the sponge body. Diagnosis. Aspidoscopulia with two rayed symmetry as seen from the top; clavules mostly with discoidal-clavate (pileate), and some small with anchorate heads; microscleres with oxyoidal, discoidal and onychoidal outer ends. Description. Body: Sponges are mostly represented by the main zigzag-shaped stem with lateral branches (Fig. 5). The lateral branches are situated along the main stem and consist of very short unbranched tubes or, rarely, dichotomously branching into two short secondary branches. The neighboring tubes or openings of lateral oscula and other derived constructions are oriented at right angle to the main stem. The lateral structures (branches, lateral oscula and derived constructions) are situated in regular, alternate position on the main stem in two opposite rows. In result, a 2 -rayed symmetry is observed in these sponges. Common structures are ridges (usually two parallel, sometimes one) along the main stem connecting the bases of lateral branches (Fig. 5 B). These ridges are variously developed, from low and hardly distinguishable to relatively high with occasional apertures. The ear-like processes (Fig. 5 F) are developed by side-by-side wall fusion and further growing up and enlargement of the space between two secondary lateral oscula (Fig. 6 e-lp, Fig. 7 C). Sometimes, usually in the lower part of the body, the same branching process leads to common formation of the carina (line of fusion of the walls of lateral branches) and equal dichotomous division of the lateral tube (Fig. 5 A, Fig. 6 lo, dblb, Fig. 7 B). This results in the appearance of two secondary lateral branches (equal to each other and to their stem) with two secondary lateral oscula. The secondary lateral oscula which accompany the ear-like processes are smaller in diameter than their homologues in dichotomous-isotomous branching (here and bellow we use terminology of plants branching); besides they are often completely overgrown with secondary skeletal framework (Fig. 6 slo). The ear-like processes are always becoming spoon-like with uniform orientation; usually they fuse with their further neighbors in the upper part of the sponge, as may be observed in some fragments (Fig. 5 E), they somehow make irregular structures of curved and anastomosing lamellae. In the terms of branching, this species in whole is anisotomous (in small specimens) with tendency to dichopodial-monopodial branching (in large specimens). Unfortunately no complete specimen was ever found in the collections. The living specimens may be sometimes covered by dense aggregations of hydrozoan and zoantharian epibionts. The holotype (Fig. 5 C) is a fragment of the main stem 75 mm in length consisting of a main tube 8–12 mm in diameter with walls 1–2 mm thick. Primary lateral oscula are 8–14 mm in diameter, the ridges between them are low, up to 3 mm high and 1 mm in thickness. One large, flat, ear-like process vertically oriented, protrudes at about 12 mm and is about 2 mm thick. It has two small secondary lateral oscula about 3 mm in diameter, situated at base and on the upper part of the ear-like processes. The paratypes are different fragments in which the stem tube and its outgrowths are 8–17 mm in diameter, sometimes with some ear-like processes up to 40 mm in diameter. Dictyonal framework: Dictyonal skeleton of euretoid type. Most tubes have inner walls of 3 layers of primary skeleton constructed of smooth beams 40–110 μm in diameter and rectangular meshes about 200 x 500 μm in size, with free rays that are rough and about 0.5 mm long. The primary skeleton (Fig. 8 A, B) underlies not only the atrial cavity but also it is present as several (4–6) inner layers of the ear-like processes (the secondary skeleton in the earlike processes has 2–3 layers on both sides). The secondary skeleton (Fig. 8 C) in the upper parts of the body is constructed by beams 20–80 μm in diameter with usually triangular meshes 50–200 μm in diameter. The small hexactines connected by fusion with dictyonal skeleton and with each other have smooth rays 50–110 / 4–8 μm in size (Fig. 8 D). Epirhyses (100–200 μm in diameter, up to 500 μm deep) are connected with all secondary framework structures; they are situated on both sides of the ear-like processes and on the surface of the main stem and lateral branches. Free spicules: Dermalia and atrialia are pentactines (Fig. 10 A, B) with unpaired ray directed inside the body. Dermal pentactines are usually larger than atrial ones, with smoother rays and with less clavate outer ends. The dermal pentactines are generally larger and their ray surface is smoother than in artrial ones. The tangential rays of dermal pentactines are 107–366 μm long, the unpaired ray is 67–348 μm long, and 7–11 μm in the diameter. The tangential rays of atrial pentactines are 59–307 μm long, the unpaired ray is 44–340 μm long and 4–9 μm in the diameter. Clavules are of two types: most have discoidal-clavate (pileate) (Fig. 9 F, G, P, Fig. 10 C–E), and some anchorate heads (8–9 teeth) (Fig. 9 J, K, Fig. 10 F–I), the latter have several spines, which are long, curved, and situated close to the head (in some specimens the latter type of clavules was not found). Their shafts are slightly rough; the end directed inside the body is rough-spiny, usually lanceolate in shape. The discoidal clavules are 196– 344 μm long, their heads are 11–26 μm long and 19–44 μm in diameter, the diameter of the shaft is about 2 μm in the middle. The anchorate clavules are 133–426 μm long, their heads are 19–56 μm long and 33–63 μm in diameter, the diameter of the shaft is about 2 μm in the middle. The aspidoscopules (Fig. 9 L– O, Q, Fig. 10 J–M), are found only in the primary framework which underlies the atrial space (they are absent in the primary framework inside the ear-like processes). The aspidoscopules have 12–14 terminal spines with conically pointed or rarely dichotomously branching outer ends and microspined surface. Their shafts are similar in shape to that of the anchorate clavules. The aspidoscopules are 118–352 μm long, their heads are 7–56 μm long and the tuft is 17–70 μm in diameter. The diameter of the shaft is about 3 μm in the middle. The clavules are situated at dermal surface while the aspidoscopules at atrial one. Uncinates (Fig. 10 P) are 200–1000 / 2–8 μm in dimensions. Microscleres: Oxyhexasters (Fig. 9 C, Fig. 10 R–T), onychohexasters (Fig. 9 A, E, Fig. 10 U) and discohexasters (Fig. 9 B, E, Fig. 10 Y) with 2–4 – rarely 5 – secondary rays, are 50–137 μm in diameter with primary rosette 25–81 μm in diameter. Rare hexactines and hemihexasters (1–4 secondary rays) are found in some specimens, they have onychoidal–discoidal outer ends and diameter 54–101 μm (Fig. 10 U-AD). These spicules may be allochthonous. The holotype and additional topotypical specimens (may be its fragments) have numerous small stellate discohexasters (Fig. 10 AC) 25–54 μm in diameter with primary rosette 7–36 μm in diameter. Such spicules were not found in other paratypes taken from other locations, and one might conclude that they are allochthonous. This idea is rejected here because they are very numerous in comparison with other definitely allochthonous spicules. Abnormal microscleres are rare oxyhexasters with very short secondary rays (Fig. 10 U, V) (MNHN p 3701), oxydiasters (Fig. 10 X) (MNHN p 5019, p 3735; fr 542), and oxystaurasters (MNHN p 1142; fr 543). Remarks. The three known species of Aspidoscopulia differ in the following characters (Table 3): A. furcillata (Lévi, 1990) has no anchorate clavules and microscleres with short primary rays; A. tetrasymmetrica sp. n. has large anchorate clavules (200–600 μm long) and only oxyoidal microscleres, while A. bisymmetrica sp. n. has small anchorate clavules (130- 140 μm long) and microscleres with oxyoidal, discoidal and onychoidal outer ends. Besides these features the species differ in their external shape (see the descriptions) but that of A. furcillata is unknown – this sponge is represented by a fragment for which body shape interpretation is impossible. Many specimens of ‘bilateral shape’ collected far from A. bisymmetrica sp. n. have no loose spicules. Nevertheless it is impossible to assign a specific body form to a particular species now. A very possible representative of this species is shown on the underwater photo (Fig. 11) taken near the type locality. continued. MNHN fr 534 MNHN p 3701 n avg min max std n avg min max std continued. MNHN p 3735 MNHN p 5019Published as part of Tabachnick, Konstantin R., Menshenina, Larisa L., Pisera, Andrzej & Ehrlich, Hermann, 2011, Revision of Aspidoscopulia Reiswig, 2002 (Porifera: Hexactinellida: Farreidae) with description of two new species, pp. 1-22 in Zootaxa 2883 on pages 8-13, DOI: 10.5281/zenodo.20366

Legislative Documents

Also, variously referred to as: House bills; House documents; House legislative documents; legislative documents; General Court documents