Research Article |
Corresponding author: Benny K.K. Chan ( chankk@gate.sinica.edu.tw ) Academic editor: Pavel Stoev
© 2016 Meng-Chen Yu, Gregory A. Kolbasov, Benny K.K. Chan.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Yu M-C, Kolbasov GA, Chan BKK (2016) A new species of sponge inhabiting barnacle Bryozobia (Archaeobalanidae, Bryozobiinae) in the West Pacific. ZooKeys 571: 1-20. https://doi.org/10.3897/zookeys.571.6894
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This paper describes a new species, Bryozobia rossi sp. n., collected by scuba diving in both Taiwan and Japan. B. rossi sp. n., a member of the subfamily Bryozobiinae (
Sponge inhabiting barnacle, Archaeobalanidae , Bryozobiinae
Barnacles of the subfamily Bryozobiinae are considered obligate symbionts of sponges attaching to various calcareous substrates, such as mollusk shells, bryozoans, corals. Morphologically, bryozobiines are unique in remaining attached to sponges substrates and possessing calcareous portals and atria (openings and tubular arched passages) in their base and walls (Table
Glossary of nomenclature relevant to Bryozobiinae. Modified from
Terms | Explanation | Types | Explanations |
---|---|---|---|
Atria | Arched chambers or passages of calcareous basis, radiating from center and opening to exterior with hemiportals and portals. | Atrial Footing | Footing area of basis |
Non-perforate Atria | Solid atria without pores | ||
Perforate Atria | Atria perforated with small pores | ||
Slit Atria | Atria perforated with elongated slits | ||
Calcipeds | Calcareous projections of shell exterior of different shape. | Finger-like Parietal Calcipeds | Finger-shaped projections of parietal wall |
Finger-like Basal Calcipeds | Finger-shaped projections of basis | ||
Blade-like Parietal Calcipeds | Blade-shaped projections of parietal wall | ||
Blade-like Basal Calcipeds | Blade-shaped projections of basis | ||
Portal | Openings on shell connected or not connected or not with atria, may be arranged in several whorls and elevated with growth of shell or not. | Portal Fillets | Sliced passage opening |
Interparietal (Sutural) Hemiportal | Non-encircled passage opening at basal part of wall plates suture | ||
Interparietal (Sutural) Portal | Encircled passage opening between wall plates at sutural area. | ||
Parietal Hemiportal | Non-encircled passage opening at base of parietes | ||
Parietal Portal | Encircled passage opening removed from base of parietes | ||
Portals connected with basal atria via arched fillets | |||
Open portals | Portals lost connection with basal atria | ||
Closed portals | |||
Footing | Massive processes of basis or basal part of parietes | Parietal Footing | Massive basal processes of parietes |
Atrial Footing | Massive processes of basis between atria |
The subfamily Bryozobiinae and the type genus Bryozobia were first described by
Currently, Bryozobiinae consists of five genera and ten species. The shell structure of all species possesses calcareous tubular passages or atria of the base remaining attached to the substratum. The number of shell plates and their fusion/elimination at the base and the structure of atria and portals (Table
Only a single species B. synaptos (
In the present study, we collected several living bryozobiines from Green Island and Orchid Island (Taiwan) and Kochi (Japan) with only an irregular whorl of shell portals and remained attached to the basal atria through arched fillets and smaller CL2 eliminated by interparietal portal. These characters suggest that this is a new species of genus Bryozobia and the presence of soft bodies completes the description of this genus.
Bryozobiines were collected from thin encrusting sponges on rocks (Agelas nakamurai
All six pairs of cirri, penis, and oral cone were dissected from the somatic bodies, and the organic debris were removed using forceps and an ultrasonic cleaner (for 1–3 seconds) and examined through light microscopy (Zeiss Scope A1, Zeiss, Germany) using high-definition lenses (Zeiss Plan APO Chromat 40X/0.95) to clearly observe the setae types on the cirri and the mouthparts.
The glossary of nomenclature relevant to Bryozobiinae and setae morphology were described according to
Bryozobia synaptos Ross & Newman, 1996
Holotype: Taiwan, Taitung, Green Island (Lyudao), Ziping, 22°37.99'N, 121°29.99'E, depth 24 m, November 15, 2011, coll. J.H.Y. Yu, ASIZCR-000338, on host sponge Agelas nakamurai (Hoshino, 1985), NPUST.POR.0357.
Paratypes: ASIZCR-000339, ASIZCR-000340 and Mg. 1222
Taiwan, Taitung, Orchid Island (Lanyu Island), Rock Shuangshihyen, 22°05.14'N, 121°34.10'E, depth 24 m, June 11, 2011, coll. J.H.Y. Yu, CEL-SOI33-1, on host sponge Theonella aff. conica (Kieschnick, 1896), NPUST.POR.0354.
Other materials: Japan, Nishidomari, Kochi, 32°46.48'N, 132°43.89'E, depth 5 m, July 22, 2011, coll. J.H.Y. Yu, CEL-SJP5-1, on host sponge Theonella mirabilis (de Laubenfels, 1954), NPUST.POR.0350.
Shell with unfused sutures, external surface with a few calcipeds and indistinct longitudinal ribs, vestige of CL2 with elevated interparietal portal on each side, an irregular whorl of open portals, and edges of parietal footings that may merge to completed portals. Calcareous base, base flat or saucer-shaped with numerous radial atria (app. 24) permeated by dense, irregularly shaped pores. Scutum with a prominent articular ridge, articular furrow low, concave pits of adductor and depressor muscles. Broad tergum with a beak-shaped apex, high and short articular ridge, and sloping spur.
White shell, tinged pinkish toward apex, with a maximal height range of 3–3.7 mm, basal diameter range of 3.3–4.6 mm, orifice range of 1.0–1.3 mm, and six plates (R-CL1-CL2-C) with unfused sutures, roughened and plicated exterior parietes with fine growth lines and few finger- and blade-like calcareous calcipeds on the surface (Figures
Bryozobia rossi sp. n., shell (opercular plates removed), general morphology. A general view, lateral side B top view. Abbreviations: C, carina; CL1, carinolateral1; CL2, carinolateral2; CP, calcipeds; FP, parietal footing; HP, hemiportals; IPP, interparietal portal; PF, portal fillets; PP, parietal portal; R, rostrum. Scale bar in µm.
Bryozobia rossi sp. n. CEL-SJP5-1. Complete shell, scuta and terga. A rostral view B lateral view C carinal view D top view E, F basal view, sponge remnants and central part of basis removed in ‘F’ showing structure of basis G external view of scuta H internal view of scuta I external view of terga J internal view of terga. Scale bars: 1 mm.
Bryozobia rossi sp. n. CEL-SOI33-1.Disassembled shell showing separated plates and part of basis after bleach treatment. A, B external and internal view of rostrum C, E external view of carinolaterals1D, F internal view of carinolaterals1G, I external view of carinolaterals2H, J internal view of carinolaterals2K, L external and internal view of carina M, N external and internal view of part of basis. Scale bar: 1 mm.
Bryozobia rossi sp. n. CEL-SJP5-1. A basal view of shell showing basis (central part destroyed) with atria and basal calcipeds B part of margin of basis with two atria and their portals (indicated by arrows) C suture (indicated by arrow) between CL1 and R, interior view D exterior view of part of shell with interparietal and parietal portals (indicated by arrows) in basal parts of CL1 and R E enlarged part of basis with porous atria F enlarged fillets of hemiportals (indicated by arrow) showing porous and sliced structure between basis and parietes, external view G basal view of interparietal portal opening H enlarged broken atrial fillet (tube) showing sliced structure (inner side of shell) I sutures between CL1, CL2 and C (indicated by arrows) and fillet of interparietal portal eliminated CL2, interior view J enlarged sutures (indicated by arrows) between CL1, CL2 and C K exterior view of interparietal portal eliminates CL2. Abbreviations: C, carina; CL1, carinilateral1; CL2, carinolateral2; R, rostrum. Scales: 1 mm (A); 0.1 mm (B–K).
Bryozobia rossi sp. n. AASIZCR-000338, Top view of shell showing unfused wall plates BASIZCR-000338, enlarged external area of shell showing CL2 eliminated by interparietal portal CASIZCR-000339, basal view of shell with partially destroyed basis DASIZCR-000339, internal view of wall plates showing unfused sutures between CL1, CL2 and C EASIZCR-000340, internal view of wall plates with basal longitudinal ribs and basis fragment with perforated atria FASIZCR-000340, enlarged part of inner wall surface with unfused suture between R and CL1GASIZCR-000340, interior view of fragment of CL1 and CL2HASIZCR-000340, enlarged view of inner suture between CL1 and CL2. Abbreviations: C – carina, CL1 – carinilateral1, CL2 – carinolateral2, R – rostrum. Scale bars in mm.
Externally, scutum (Figure
Labrum bilobed, separated by deep V-shaped notch (Figure
Mandibular palp ovate with concave outer margin (Figure
Mandible with five teeth (Figure
Maxillule with a straight cutting edge and seven large cuspidate setae, and the upper and lower pairs largest (Figure
Maxilla bilobed, with a triangular distal portion with a truncated outer edge (Figure
Cirrus I with unequal rami, anterior ramus with eleven segments, twice as long as the posterior ramus (five segments; Figure
Bryozobia rossi sp. n. ASIZCR-000338. Cirri I (left, view from the posterior side) (A–D), II (left, view from the anterior side) (E–H). A cirrus I B tuft of setae on at base of protopod C, D distal segments of posterior and anterior rami E cirrus II F setae on posterior margin of protopod G, H distal segments of anterior and posterior rami. Scale bars in μm.
Cirrus II with unequal rami, posterior ramus (six segments) shorter than the anterior (eight segments; Figure
Cirrus III with subequal rami, a ten-segmented posterior ramus, nine-segmented anterior ramus (Figure
Cirrus IV with unequal rami, a twelve-segmented anterior ramus, a posterior ramus broken with eleven segments on its remaining part (Figure
Bryozobia rossi sp. n. ASIZCR-000338. Cirri III (left, view from the posterior side) (A, B), IV (left, view from the anterior side) (C–H). A cirrus III B distal segment of anterior ramus C Cirrus IV D setae and denticles on basis E, F teeth on proximal segments of anterior ramus G intermediate segments of anterior and posterior rami H distal segments of anterior ramus. Scale bars in μm.
The cirri V and VI were similar in length, with the anterior rami of cirri V and VI both having twenty-one segments, and the posterior rami of cirri V and VI were both broken, with nine and fifteen segments on their remaining parts, respectively. A short and simple protopod was observed on the anterior margin and long serrulate setae on the posterior margin (Figure
The penis was approximately the same length as the cirrus VI, finely annulated, gradually tapering at the tip (Figure
Bryozobia rossi sp. n. ASIZCR-000338. Cirri V (left, view from the anterior side) (A–C), VI (left, view from the posterior side) (D–F) and penis (G–I). A cirrus V B setae on intermediate segments of posterior and anterior rami C distal segment of posterior ramus D cirrus VI E setae on intermediate segments of posterior and anterior rami F distal segment of anterior ramus G penis H rudimentary basidorsal point I setae on tip. Scale bars in μm.
We named the organisms after the famous cirripedologist late Prof. Arnold Ross (Scripps Institution of Oceanography, USA), who discovered the subfamily Bryozobiinae.
All previously described specimens of Bryozobia synaptos from Madagascar and Mauritius and Bryozobia sp. from Sri Lanka possess several (two to three) more or less regular whorls of shell portals (
The previously described Bryozobia from Madagascar, the Mascarene Plateau and Sri Lanka states that the radii between the R-CL1 are obsolete, whilst radii between R-CL1 in B. rossi sp. n. in the present study is well developed. In addition, the original diagnosis of Bryozobia from Madagascar and the Mascarene Plateau did not include parietal calcipedia, in which this character is present in B. rossi sp. n. In the present study, we conclude it is premature to modify the diagnosis of Bryozobia due to whether these discrepancies are ecotypic or specific differences is unknown. We propose to include B. rossi as incertae sedis in Bryozobia, deferring a decision as to whether or not it is a new genus in the Bryozobiinae when further molecular phylogenetic analysis is conducted in bryozobiine species.
The previously studied specimens of Bryozobia were represented by subfossil materials. The present description is the first for the morphology of the oral cone, cirri, and penis in this genus. Their morphology does not differ considerably from that in other bryozobiines, and cirrus IV with recurved teeth, characteristic of most of these barnacles. This is a first discovery of Bryozobia in Pacific; the previous ones were from the Indian Ocean.
The morphological structures, such as atria, portals, pores of basis, calcipeds, and armament of cirri IV, were attached to the teratogenesis, and the adaptations of symbiosis to the sponge are the topics predominantly discussed in the bryozobiines (
We agree with suggestion of
Only one species of Bryozobiinae was previously reported from the studied area, namely Eoatria quinquevittatus (
We are indebted to Dr. Robert J. Van Syoc and Profs William A. Newman and John S. Buckeridge for invaluable consultations and comments on bryozobiines. We are grateful to Drs. Nicole J. de Voogd and Yusheng M. Huang for the advice on sponge identification. For GAK this work was financially supported by the Russian Foundation for Basic Research (grants 14-04-92002 NNS_a, 15-29-02447 ofi_m) and the grant of the Council of President of Russian Federation NSH-7770.2016.4. MCY supported by studentship offered by Doctoral Degree Program in Marine Biotechnology, National Sun Yat-sen University and Academia Sinica, Taiwan. BKKC is supported by the Russian-Taiwan collaboration project, Ministry of Science and Technology, Taiwan (MOST-103-2923-B-001 -003 -MY3). Thanks to Wallace Editing Co. Ltd, Taiwan for editing the English of the manuscript.