Cheilostome Bryozoa from Penang and Langkawi , Malaysia

Twenty-three species of cheilostome bryozoans are described from the Malaysian islands of Penang and Langkawi based on a brief reconnaisance survey of shore localities. These are the first bryozoans to be formally described from either island and they demonstrate the potential for further research on these neglected suspension feeders. Of the 23 species recorded, 12 are anascans, half of which are malacostegines, and 11 are ascophorans. The new combinations Acanthodesia falsitenuis (Liu, 1992), A. perambulata (Louis & Menon, 2009) and A. irregulata (Liu, 1992) are introduced. Most of the species recorded are widespread in the Indo-Pacific, and some are apparently globally distributed in the tropics and subtropics, including the invasive fouling species Bugula neritina, Hippoporina indica and Schizoporella japonica, as well as the coral reef associates Cranosina coronata and Hippopodina feegeensis. Plastic debris and glass bottles were encrusted by Jellyella eburnea, a coloniser of floating biological and man-made objects that is becoming widespread in the tropics and subtropics of the world’s oceans.


Introduction
Bryozoans are a phylum of colonial metazoans, numbering almost 6000 species (Bock & Gordon 2013) and found in all of the world's oceans.Knowledge of bryozoan faunas is still remarkably poor for some parts of the world.Among these are the seas around Malaysia.For example, the review of coastal marine biodiversity in Malaysia by Mazlan et al. (2005) contains no mention of bryozoans.As bryozoans are common fouling animals, this is clearly anomalous and undoubtedly reflects lack of study rather than the true absence of these benthic suspension feeders.Bryozoans provide habitats and the food for numerous other marine animals (e.g., Bradstock & Gordon 1983;Cocito 2004;Wood et al. 2013), including commercial species, and therefore concern about their vulnerability to environmental change is not entirely academic.In particular, most bryozoans have calcareous skeletons that in tropical species include an apparently high proportion of species biomineralizing aragonite or magnesium-calcite (Taylor et al. 2015), minerals susceptible to ocean acidification because of their relatively high solubilities.

Localities
Shore collections were made from the following localities in Penang and Langkawi (Fig. 1).

Penang
1. Batu Uban (5°22' N, 100°19' E): a fishing wharf located on the eastern side of the island next to the main bridge between the peninsula and the island.2. Batu Maung (5°27' N, 100°17' E): a fishing wharf at the eastern side of the island sheltered by a peripheral island (Pulau Jerejak).3. Pulau Betong (5°18' N, 100°11' E): a commercial oyster aquaculture centre on floating cages off the coast of the small island of Pulau Betong southwest of the main island of Penang.4. Balik Pulau (5°22' N, 100°12' E): sandy beach in the southwestern part of Penang.Langkawi 1. Pantai Beringin (6°17' N, 99°51' E): sheltered sandy beach in a small bay on the southeastern part of the island with rocky shore at both ends of the beach.2. Kuah jetty (6°18' N, 99°51' E): small wooden jetty adjacent to the main ferry terminal.3. Pekan Rabu (6°19' N, 99°50' E): floating dock built from modular plastics connected to each other and used as a docking area for small local boats.4. Sungai Menghulu (6°19' N, 99°48' E): a fishing wharf at the river mouth leading to the Straits of Malacca in the south of the island.5. Kampung Kuala Temoyong (6°17' N, 99°44' E): a fishing wharf at the river mouth leading to the Straits of Malacca in the southwest of the island.6. Teluk Baru (6°15' N, 99°44' E): a large wharf located in the southern part of the island used for tourist and fishing boats.7. Pantai Chenang (6°17' N, 99°43' E): exposed sandy beach at the southern tip of the island, forming a narrow shoreline frequented by tourists.8. Pantai Pasir Hitam (6°25' N, 99°47' E): sandy beach with fine sand in the north of the island.A reef flat composed of discontinuous growing corals is located about 30-40 m seawards from the beach.The reef is highly sedimented with fine sand.

Repository
All figured specimens are deposited in the collections of the Marine Science Laboratory, Universiti Sains Malaysia, Penang (abbreviated MSL).Letters following the number are used to indicate different species encrusting the same specimen.

Study methods
Collections were made by examining all available artificial and natural hard substrates evident at the localities visited, using a hand lens to confirm the presence of bryozoans.Only a small proportion of mollusc shells was found to be bryozoan-encrusted, but artificial substrates, such as pier wharves and fishing floats, were very commonly fouled by bryozoans.Specimens were washed and dried after collection.After preliminary study with a binocular microscope, specimens of each species present were chosen for scanning electron microscopy (SEM).Prior to SEM, colonies were bleached for up to a day in a dilute solution of commercial bleach to remove soft tissues and expose the skeleton.The exact time of bleaching was adjusted according to the species concerned and the requirement to conserve features such as delicate spines while removing cuticular components including the opercula.Bleached colonies were studied uncoated using a LEO 1455-VP scanning electron microscope and employing a backscattered electron detector.Measurements were made from SEM images.

Taxonomic descriptions
The descriptions below are based entirely on material collected from Penang and Langkawi and are not intended to be comprehensive for the species described.Synonymies are abbreviated to include only the original description plus one key recent reference.All measurements were taken from SEM images of Malaysian specimens, with ranges of autozooid lengths and widths usually based on 10 zooids.

Description
Colony encrusting, uniserial, runner-like with widely spaced branches (Fig. 2A-B), delicate, feebly calcified.Autozooids slender with elongate pyriform proximal base and an erect distal part; proximal base 1.1-1.3mm long by about 0.13 mm maximum width (Fig. 2C), with irregular transverse growth wrinkles and locally minutely porous or with finely reticulate ornamentation, a narrow proximal cauda of about same length as broader distal part; erect part often broken off or collapsed, about 0.42 mm long by 0.07 mm maximum width, proximally with widely spaced, hoop-like annulations about 0.02 mm apart (Fig. 2D), expanding a little distally where an elongated opesia, 0.25 mm long by 0.05 mm wide, is developed on proximal-facing side (Fig. 2E).

Remarks
This species was erected by Busk (1852) based on material collected by Charles Darwin from the coast of Patagonia and the Magellan Strait.Busk's figure shows clearly the coarsely annulated erect parts of the zooids, very different from the finely striated annulations seen in the two common cosmopolitan species Aetea anguina (Linnaeus, 1758) and A. sica (Couch, 1844).A modern systematic study of Aetea combining morphological and molecular data is required and in the meantime there must be reservations about the identities of species with such seemingly wide latitudinal distributions as A. ligulata.
Abundant evidence of damage and repair can be observed in the skeleton.The skeletons of some zooids were apparently partly destroyed, eliciting reparative growth, sometimes on multiple occasions (Fig. 2C).
Broken zooids may also reveal internal stolon-like structures (Fig. 2F), indicating growth through the dead zooid to re-establish connections between zooids and allow growth from the open ends of branches.
Although the straggly, runner-like form of Aetea and various other uniserial cheilostomes would suggest a reduced commitment to maintaining the integrity of the colony, reparative growth that renews links between zooids and re-uses substrate space once occupied by dead zooids is a common feature of such bryozoans, Recent and fossil (Taylor 1988).

Remarks
The genus Acanthodesia, with the type species Membranipora savartii Audouin, 1826 (see Taylor & Foster 1994), is here interpreted to include numerous species once assigned to Membranipora but having more robustly calcified colonies, or, alternatively, to Biflustra but generally having encrusting colonies rather than the erect vincularian colonies of the type species of this genus.Although many bryozoologists use Biflustra in preference to Acanthodesia, the critical early astogeny is unknown in the type species of the former genus.
The paucity of skeletal morphological characters -avicularia and ovicells are lacking -makes species identification difficult.Molecular studies are much needed in this genus to clarify its diversity.
0.73 mm long by 0.30-0.40mm wide, zooidal boundaries marked by a fissure; mural rim salient, narrow, pustulose, pustules forming a single row; opesia occupying most of frontal surface, rim broadened distally, edged with tiny pustules; gymnocyst lacking; cryptocyst occupying one-third to almost one-half of proximal end of zooid, planar, sparsely pustulose, with a variably developed, anvil-shaped process bearing long spines extending for up to 0.14 mm over opesia (Fig. 3B-C); no spine bases, spinules or tubercles.Kenozooids developed at convergences between colony lobes (Fig. 3A, upper right corner), variable in shape and size, opesia ovoidal.

Remarks
The most striking feature of this species is the anvil-shaped, spinose cryptocystal process projecting over the opesia (Fig. 3B-C).Similar processes were depicted in zooids of two species from the South China Sea -Acanthodesia similis (Liu, 1992) (see Liu et al. 2001: pl. 9, fig.2) and A. falsitenuis (Liu, 1992) (see Liu 1992: fig. 3) -and also in Acanthodesia crenulata (Okada, 1923), described by Tilbrook (2006: pl. 2b) from the Solomon Islands.Autozooids of A. similis are about half the length of those of the species described here from Langkawi, but judging from the scale bar shown by Liu (1992) in his figure of A. falsitenuis, this latter species is about the same size as the Langkawi material.However, the cryprocystal process is less developed in the Chinese material of A. falsitenuis and this also has zooids of a more rectangular shape with more ragged edges to the lateral cryptocyst.

Remarks
This species was originally described from Cochin, India, where colonies are erect and bilamellar, unlike the encrusting colonies from Langkawi assigned here to Acanthodesia perambulata.However, the skeletal morphology and dimensions of the autozooids is almost identical in the Indian and Malaysian material and it is known that a single species can exist as either encrusting or erect bifoliate colonies.Tilbrook & Gordon (2015) list this species (as Biflustra perambulata) from the Straits of Johor, Singapore.Compared to the similar species Acanthodesia grandicella Canu & Bassler, 1929(e.g., Gordon et al. 2008;Tilbrook 2012), A. perambulata has smaller zooids that are less granular and have weaker calcification.Nevertheless, molecular sequence data is needed to show that these fouling invasive species really are distinct from one another.

Remarks
Acanthodesia irregulata was originally described from the South China Sea and subsequently identified by Gordon et al. (2007) from Bangladesh.Two characteristic features were noted by Liu (1992): the presence of cuticular spinules on the frontal membrane and operculum, and tubercles at the proximal corners of some of the zooids.The former have not been observed in the studied material from Malaysia, which is bleached.However, tubercles do occur in some of the studied Malaysian specimens (Fig. 3K-L) and the size of the autozooids is very similar to that given by Gordon et al. (2007) in their Bangladeshi material.The paucity of taxonomic characters in the skeleton of the Malaysian specimens precludes certain identification as A. irregulata.It should also be noted that more than one species may be represented in Penang to judge from the variations in skeletal morphology; for example, tubercles can be present (Fig. 3K-L) or absent (Fig. 3G-J), and the width of the mural rim varies between specimens (Fig. 3G-L).

Remarks
This species was fully described by Taylor & Monks (1997) who made it the type species of the new genus Jellyella, noting the pan-oceanic, tropical to subtropical occurrence of J. eburnea as an encruster of floating shells of the squid Spirula, and occasionally of the living planktonic gastropod Janthina.The pseudoplanktonic ecology of J. eburnea has apparently 'pre-adapted' it to the colonization of floating anthropogenic debris, especially plastic objects (e.g., Moyano 2005) but also glass bottles (Fig. 4D-E).

Remarks
The genus Arbopercula -type species Electra bengalensis Stolizcka, 1869 -was proposed by Nikulina (2010) for species previously included in Electra, but which have spines on the operculum.These unmineralized structures have not been observed in the dried material from Penang, which has lost the opercula.Nevertheless, the Penang bryozoan does show a strong overall resemblance to the specimen figured by Gordon et al. (2007, fig. 1C) as the type species, particularly in the gymnocystal spinosity, and also to Arbopercula devinensis (Robertson, 1921), although differences in the distribution and number of spines, plus the extent of the proximal gymnocyst, preclude unequivocal identification as either of these two species.

Material
MALAYSIA: MSL BRY010, Batu Muang, Penang, encrusting a barnacle from debris adjacent to a fishing jetty.

Remarks
The original figure of Robertson (1921: fig. 6) shows zooids with branching spines at the distolateral corners.Although spines are not preserved in the studied material from Penang, their bases are clearly visible in these locations.Robertson's Chinese material also has slightly shorter cryptocystal spinules and the opesia is ellipsoidal in outline compared with the elongate inverted pear-shaped opesia of the Penang specimens.However, Liu et al. (2001: pl. 18, fig. 3) figured a Chinese specimen of S. amoyensis with longer spinules and opesia that broaden distally.A putative colony of this species epizoic on a turtle has broader autozooids and short cryptocystal spinules (Frazier et al. 1992: fig.1).In view of the morphological variability encompassed by specimens assigned to the species, the Penang material can be identified as S. amoyensis.
Not seen in the Malaysian specimens, but sporadically developed elsewhere in this species, are vicarious avicularia (e.g., Liu et al. 2001: pl. 18, fig.3).These are longer and wider than the autozooids, and the distal part of the opesia is particularly broad, raised slightly and separated from the proximal part by two small, condyle-like indentations.

Description
Colony encrusting, multiserial, unilamellar or multilamellar.Ancestrula and early astogeny not observed.Autozooids subovoidal, about twice as long as wide, 0.34-0.40mm long by 0.18-0.40mm wide; zooidal boundaries marked by a narrow fissure; opesia occupying one-half to two-thirds of frontal surface, pear-shaped, generally pinched slightly at about two-thirds of length; cryptocyst well developed proximally and shelf-like, tapering distally, pustulose; gymnocyst visible proximally and proximolaterally, narrow, tapering distally; spines lacking.Ovicells not observed in studied Malaysian material but elsewhere described as small, partly immersed in distal zooid and with cap-like ooecia (e.g., Tilbrook 1998).Avicularia interzooidal, directed distally, small, about 0.06-0.09mm long by 0.04-0.05mm wide, present at proximal corner or less often at two proximolateral corners of most autozooids; rostrum rounded, a little longer but narrower than opesia.

Remarks
Large vicarious avicularia sometimes develop in this species (e.g., Tilbrook 1998: fig.2e) but were not seen in the studied colony from Langkawi.Antropora minor is widely distributed in the tropics, occurring in the Caribbean, South Atlantic, Pacific and Indian Oceans, including East Sumbawa, Malaysia (Tilbrook 1998).

Remarks
This species has often been regarded as a junior synonym of Nellia tenella (Lamarck, 1816), but following Winston et al. (2014) we here retain Busk's species name oculata pending a revision of Lamouroux's material to test the synonymy.Ostensibly, Nellia oculata has a wide tropical and subtropical distribution, as well as a long fossil record, but there is need for a taxonomic re-evaluation using molecular data.

Description
Colony erect, weakly mineralized, forming a luxuriant bush comprising bifurcating branches with zooids in two alternating rows opening on one side of branch, purple-brown in colour.Autozooids slender, about 0.48-0.56mm long by 0.15-0.18mm wide; opesia occupying almost all of frontal surface, squared-off distally; operculum absent; gymnocyst forming sides and back walls of zooids; spines and cryptocyst lacking; ovicell globular, large and prominent (Fig. 8B), attached to inner distal angle of zooid by a short peduncle.Avicularia lacking.

Remarks
Considerable attention has been focused on Bugula neritina as a source of the natural product bryostatin.
Molecular studies have recently shown that morphologically defined, B. neritina is a complex comprising at least three separate species (Fehlauer-Ale et al. 2014).The complex is very widely distributed in tropical, subtropical and even temperate waters, and is an important fouling taxon dispersed anthropogenically (e.g., Ryland et al. 2011). Family

Description
Colony erect, bushy, jointed, dichotomously branched, ramifications typically after every four zooids, zooids arranged alternately and opening on one side of branch only.Autozooids elongate, about 0.40-0.50mm long by 0.20-0.24mm wide; opesia occupying most of frontal surface, oval; gymnocyst moderately well developed proximally; cryptocyst very narrow, smooth; 4 or 5 long, basally articulated spines in distal half of zooid, the one that is more proximal and closest to branch axis forming a scutum bending over frontal membrane and bifid at the end (Fig. 8F); ovicell globular, wider than long, ectooecium with about 4-6 distal pores near distal edge, circular or radially elliptical (Fig. 8F).
Avicularia small, located either on: (1) proximal gymnocyst on side closest to branch axis, orientated transversely or proximolaterally and facing outwards, often absent, variable in size, rostrum dentate, tip hooked; or (2) edge of branch close to distal end of autozooids, orientated outwards and facing distally, rostrum triangular, tip hooked.Vibracula located on outer proximal gymnocyst of autozooid, orientated proximally, seta up to 1 mm long.

Description
Colony erect, rigidly calcified, bushy (Fig. 9A), comprising bifurcating, bifoliate, strap-like branches, about 2.2-2.5 mm wide, with approximately a dozen series of zooids across width of branch.Autozooids small, rounded hexagonal, longer than wide, 0.29-0.38mm long by 0.19-0.24mm wide, distinct with deep interzooidal grooves, frontal shield convex, a slight umbo sometimes developed centrally, densely granular in surface texture, with large areolar pores covering most of surface; primary orifice more or less equidimensional, about 0.08 mm long, a shallow U-shaped sinus separated from anter by small condyles (Fig. 9E); secondary orifice somewhat transversely elliptical, a subcircular spiramen separated from secondary orifice by a calcified bridge in mature zooids (Fig. 9F-G).Gonozooids larger than autozooids, with a broad, shallow orifice separated from a wide spiramen by a deep calcified bridge with a process on proximal edge.Adventitious avicularia (Fig. 9F) developing on frontal shield of autozooids, often laterally to spiramen but occasionally more proximally, generally one or two per autozooid, sometimes absent, orientated variously; rostrum high gothic arch-shaped; cross-bar uncalcified; opesia rounded, a little wider than rostrum.Vicarious avicularia sporadically distributed (Fig. 9D), longer than autozooid, about 0.57 mm long by 0.21 mm wide; rostrum elongate, spatulate with a distal shelf; crossbar uncalcified; opesia roughly semicircular with a sloping cryptocyst-like proximal edge; frontal shield with areolar pores similar to those of autozooids.Kenozooids present along some branch edges.

Remarks
Found among debris discarded from a fishing net, Adeonella lichenoides is the only rigidly erect bryozoan collected in either Langkawi or Penang during the fieldwork in October 2013.This species is distributed throughout the Indo-West Pacific region (Hayward 1988).

Remarks
Malaysian specimens of Celleporaria aperta clearly show the dentate distal tips of the avicularian rostra (Fig. 10F), like those depicted by Hincks (1882: pl. 5, fig.3), but not apparent in all material attributed to the species by subsequent authors.Hincks (1882: 126) gave the provenance of his material as "Singapore or Philippines" and the species is regarded as widespread in the tropical and subtropical Indo-Pacific (Gordon et al. 2007).

Remarks
Parasmittina is a very diverse genus with a global distribution.Different species are best characterised by their avicularia, which are often of more than one morph within a single colony.First described formally from South China (Liu et al. 2001), Parasmittina winstonae has three kinds of avicularia: small acuminate, small plectrum-shaped, and giant.The distally directed giant avicularia in P. winstonae (Fig. 11F) are very unusual, as giant avicularia in Parasmittina are normally directed proximally, for example in the numerous species described by Soule & Soule (1973), Hayward & Parker (1994) and Harmelin et al. (2009).Harmer (1957: 943) noted the rarity of distally directed giant avicularia when describing material, some from Malaysia and since assigned to P. winstonae by Liu et al. (2001: 802), as Smittina parsevalii (Audouin, 1826).Likewise, the small plectrum-shaped avicularia lateral to the orifice are highly unusual, if not unique, to P. winstonae within Parasmittina.Liu et al.'s (2001) original description of this species from the South China Sea gives a slightly longer autozooid size (0.37-0.67 mm) than both the Malaysian material described here (0.32-0.45 mm) and specimens from the Solomon Islands (c.0.45 mm) described by Tilbrook (2006), who did not mention the presence of plectrum-shaped avicularia.This leaves some doubt about whether the three occurrences are truly conspecific, which will require further studies to test.Liu et al., 2001 Fig. 12A-C Parasmittina raigioidea Liu et al., 2001: 629, pl. 58, figs 1-2.

Description
Colony encrusting, multiserial, unilamellar.Ancestrula and early astogeny not observed.Autozooids subhexagonal, distally rounded, about 0.24-0.51mm long by 0.19-0.27mm wide; boundary walls salient with a fine fissure; frontal shield convex, coarsely pustulose, about 20 marginal areolar pores separated by ridges, impinging on central part of shield in older zooids, no pseudopores; primary orifice elliptical, about 0.09 mm long by 0.10 mm wide, lappets developed laterally, lyrula broad, about 9 µm high by 25 µm wide at top edge, condyles present about one-quarter along orifice; oral spine bases numbering 1 or 2; ovicell not observed.Avicularia adventitious, variable in size, shape and orientation but not clearly polymorphic (i.e., intermediates existing between common morphologies); usually located lateral to orifice or on proximal frontal shield, the former directed proximally, the latter distally or laterally, 0.08-0.23 mm long by 0.05-0.08mm wide; rostrum acutely triangular to spatulate with a moderate shelf, straight or slightly curved; cross-bar calcified, straight to concave; opesia semielliptical.

Remarks
Acknowledging the problems in discriminating between species of Parasmittina, this material is tentatively assigned to P. raigioidea, a species described originally from South China, on account of the similar range of avicularian morphologies to those seen in pl.58, figs 1 and 2 of Liu et al. (2001).These authors recognised two types of small avicularia -triangular and spatulate -as well as giant avicularia.The Malaysian material shows a range of avicularian morphologies and sizes and it is unclear whether there is one highly variable type of avicularium or several polymorphs.

Description
Colony encrusting, multiserial, unilamellar.Ancestrula and early astogeny not observed.Autozooids subhexagonal, small, about 0.24-0.32mm long by 0.18-0.24mm wide; boundary walls salient with a fine fissure; frontal shield convex, coarsely pustulose, marginal areolar pores large, no pseudopores; orifice slightly wider than high, about 0.09 mm long by 0.10 mm wide, lappets well-developed, highest proximolaterally, tapering distally, a sloping shelf-like proximal orificial rim extending between lappets, lyrula variable, condyles stout; usually two oral spine bases, occasionally one or three; ovicell broader than long, observed only partly formed.Avicularia adventitious present on a small minority of autozooids, located proximolaterally or laterally of orifice, directed proximally or less often laterally, variable in size, up to 0.21 mm long by 0.08 mm wide; rostrum acutely triangular with rounded end, shelf variable, occupying up to one-half length; cross-bar complete or with a medial gap; opesia semi-elliptical.

Remarks
Compared with the other three species of Parasmittina, this unidentified species has very sparse avicularia and prominent lappets highest at the proximolateral corners of the orifice and tapering in height distally (Fig. 12I).There are some similarities with Parasmittina hastingsae Soule & Soule, 1973(see Tilbrook et al. 2001: fig. 14c-d), but the latter has larger autozooids with long condyles and the lappets are highest mediolaterally rather than proximolaterally.

Description
Colony encrusting, multiserial, unilamellar, except for frontal buds covering early astogenetic stages and apparent reparative growths.Autozooids subrectangular, elongate, 0.35-0.63mm long by 0.23-0.33mm wide; frontal shield gently convex, pustulose, porous, with large marginal areolar pores and large pseudopores, which are lacking from an apron proximal of orifice; orifice longer than wide (Fig. 13B), about 0.13 mm long by 0.11 mm wide, sinus broad and shallow, with medial edge almost straight, a pair of proximally directed, pointed condyles separating sinus from semicircular poster, closed by cryptocystal calcification in some zooids (Fig. 13C); ovicell hyperstomial, prominent, broader than long, about 0.16-0.18mm long by 0.21-0.23 mm wide; about 10-20 rimmed pores of various shapes and sizes, becoming overgrown from the margins by a lamina of interior wall (Fig. 13D-E).Avicularia adventitious, small, about 0.10 mm long by 0.07 mm wide, normally located laterally to orifice and directed distolaterally towards orifice, usually single, lacking in many zooids, occasional avicularia with variable orientations present more proximally; rostrum pointed, arch-shaped; cross-bar calcified, narrow; opesia semielliptical, broader than long.

Remarks
Ryland et al. (2014) comprehensively redescribed Schizoporella japonica and provided information on its geographical distribution, focusing especially on its recent introduction into western Europe.Living colonies of S. japonica from Langkawi have a vibrant yellow-orange colour, similar to the specimen from Friday Harbor, Washington depicted by Ryland et al. (2014: fig. 2d), although some of the colonies described by these authors are redder in colour.The Langkawi material has rather smaller autozooids than is usual for this species, which may reflect the warm ambient seawater temperature, and the avicularia tend to be slightly more laterally orientated.

Description
Colony encrusting, multiserial, unilamellar or multilamellar, often large in size; growing edge revealing line of buttressed pores in transverse walls.Ancestrula and early astogeny not observed in studied Malaysian material; elsewhere ancestrula comprising a tetrad of zooids (e.g., Tilbrook 1999: fig. 1b).

Remarks
This is a common species circumtropically, often occurring in coral reefs, which is widely distributed in the Pacific, Indian and Atlantic Oceans and also recorded from the Mediterranean and Red Seas (see Powell 1969: fig.2).The large sizes of both the colonies and their constituent zooids are notable.
Colonies of this species found at Pantai Pasir Hitam, Langkawi were remarkable for being concentrated in a small area and absent from similar-looking habitats in the area.This suggests localized recruitment, perhaps from a single founding colony.

Remarks
Microporella is a highly species-rich genus with a global distribution (Taylor & Mawatari 2005).Differences between species can be very subtle.The species described here is characterized by having: (1) unpaired avicularia, often lacking altogether, laterally directed; (2) a broad crescent-shaped ascopore set in a wide rugose prominence; (3) three oral spines; and (4) an orifice lacking both teeth and condyles along the proximal edge but having a beaded distal edge.A beaded (or denticulate) distal orificial edge occurs in relatively few species of Microporella, such as M. serrata Mawatari & Suwa, 1998, M. rogickae Winston, Hayward &Craig, 2000, andM. browni Harmelin, Ostrovsky, Cáceres-Chamizo &Sanner, 2011.In M. serrata the avicularia are located much more distally than in the species from Langkawi and the ascopore is cribriform.Condyles are present at the proximolateral corners of the orifice in both this species and M. rogickae, the latter having 4-5 oral spines (cf. 3 in the species described here) and a much thicker proximal edge to the personate ovicells, whereas in M. serrata 4 oral spines are present and the ovicells are not personate.Although the Langkawi species may be new, its formal description must await additional material.

Remarks
This widely distributed species was revised by Harmelin et al. (2012) who noted its preference for gastropod shells.The two colonies collected in Malaysia, one from Langkawi and the other from Penang, are both on gastropod shells, though not a living gastropod in the case of the Langkawi specimen, which encrusts an interior surface.

Discussion
There appear to be no descriptions in the literature of bryozoans from either Penang or Langkawi, and the only mention of a bryozoan that could be found from either island is in a paper (Waters 1885: 287) describing Australian fossils in which a bryozoan identified as Membranipora savartii Audouin (probably one of the species of Acanthodesia described above) is recorded in Penang.The notion that bryozoans might be rare was dispelled by the discovery of 23 species, some abundant, during just a few days of shore collecting.Given the economic importance of the marine environment for these islands, it is remarkable that bryozoans, many of which are significant foulers of man-made structures, have been totally neglected in the past.
Of the 23 species collected during the current shore survey, 14 were found only at Langkawi, 6 only at Penang and 3 at both islands.In terms of taxonomy, 12 of the species recorded are anascan cheilostomes and 11 ascophorans.Half of the anascans are malacostegines, a group characterised uniquely among living cheilostomes by the possession of planktotrophic, cyphonautes larvae.The high proportion of malacostegines may be due to the long-lived larvae, allowing colonization of floating substrates by some species (notably Jellyella eburnea), and also the ability of other species to tolerate low and fluctuating salinity environments (e.g., Winston 1977), such as those with high levels of freshwater run-off.Surprisingly, no cyclostome bryozoans were found, but the failure to record soft-bodied ctenostomes may simply be due to the fact that most samples were collected in a dry condition.
Only 4 of the 23 species have erect colonies, the majority being encrusters.Unique in having robustly calcified erect colonies is Adeonella lichenoides.This ascophoran was found at one locality on Langkawi among what appeared to be fishing by-catch.It seems possible that it came from deeper waters further offshore than the other bryozoans recorded here.This is supported by the 5.5-113 m total depth range of the material of A. lichenoides listed by Hayward (1988).
Several of the species collected are known to be invasive foulers.These include Bugula neritina, Hippoporina indica and Schizoporella japonica, which are becoming more widespread at the present day (see, e.g., http://invasions.si.edu/nemesis/browseDB/GroupSummary.jsp?GRP=Bryozoans).The impacts of these species on the indigenous biota, as well as on economic fisheries and on ships and man-made structures such as wharves, are in general poorly understood and completely unknown in Malaysia.
Appreciation of the true diversity of bryozoans around Penang and Langkawi and their geographical and habitat distributions will require considerably more research, employing denser sampling and diving and dredging to obtain bryozoans from subtidal habitats including reefs.For instance, cobbles from subtidal soft bottoms in nearby southwest Thailand were found by Sanfilippo et al. (2011) to be colonized by a rich fauna of bryozoans.No comparable sampling for bryozoans has yet been done in Malaysia.

Fig. 1 .
Fig. 1.Map showing sampling localities in Langkawi (top left) and Penang (bottom left), and the locations of these islands in Malaysia (right).
It has not been possible to identify this species of Parasmittina despite the combination of distinctive large vicarious avicularia and small adventitious avicularia of spatulate and acuminate types.Pending a more detailed study and a comprehensive comparison with the myriad of species of Parasmittina, it is therefore left in open nomenclature as Parasmittina sp. 1. BRY012b, Kampung Kuala Temoyong, Langkawi, colony encrusting interior of large gastropod shell.
DescriptionColony encrusting, multiserial, unilamellar; growing edge stepped, revealing distolateral pore windows, generally three in each distolateral wall.Ancestrula and early astogeny not observed.Autozooids subhexagonal to almost diamond-shaped, stout, about 0.40-0.50mm long by 0.34-0.44mm wide; zooidal boundaries marked by Vieira et al. (2014)have recently subdivided the species-rich genus Scrupocellaria.The taxonomy of this group is complex and the material collected from Langkawi is tentatively assigned to the genus Cradoscrupocellaria pending a more detailed study.
(Tilbrook 2012)2008)bed as late as 1978 (from Bombay Harbour), Hippoporina indica is rapidly becoming widespread as an invasive fouling species.It has been reported from the southeastern USA(McCann et al. 2007), New Zealand(Gordon et al. 2008)and Australia(Tilbrook 2012), and its presence in Penang and Langkawi is therefore unsurprising.
oral spines numbering three in non-ovicellate zooids, one distal medial and two lateral, level with orifice mid-length, not visible in ovicellate zooids; ascopore crescent-shaped, about 0.04 mm wide, toothed, set in a rugose prominence about 0.06 mm long by 0.08 mm wide, close to proximal edge of orifice, but separated by a narrow band of non-porous frontal shield (Fig.15E); ovicell personate, proximal border of secondary orifice broadly U-shaped, ooecium broader than long, about 0.16 mm long by 0.20 mm wide, porous except in the most proximal medial part, calcification continuous with that of frontal shield of distal zooid, on which ovicell rests without extending as far distally as ascopore.Adventitious avicularia present in a minority of autozooids, single, located about mid-length on autozooid, directed laterally outwards, small, about 0.08 mm long by 0.06 mm wide; rostrum with concave sides and open end (i.e., channeled); mandible setose, almost twice length of rostrum; opesia semicircular.