Identification of sponge species Species identification is important for ecological, evolutionary, systematic, and biodiversity studies, many of which contribute to the development of conservation and management plans. Many marine species can be identified using pictorial guides that highlight their main physical characteristics. However, there are also many marine species of lesser-known groups, such as sponges, that are hard to identify with photographs or illustrations due to their lack of complex morphological characters, and thus require specialized techniques. Identifying sponges taxonomic levels. For example, the classes of known sponges are separated based on these The identification of sponges is very difficult due to characteristics: the Calcarea have calcium carbonate their unique morphological traits and intraspecific spicules, the Hexactinellida, siliceous spicules and variability in shape and colour. Therefore, proper the Demospongiae, siliceous spicules and sponging identification often requires collection and fibres or both. microscopic examination of their skeleton. Still, many observable morphological characters can Common features used to identify sponges are the be used to aid in sponge identification including following: overall shape, distribution of surface pores, colour, texture and size. Knowledge of other non- 0 Spongin fibres – organic skeletal elements made morphological characteristics, such as the ecological of collagen and forming very complex networks in traits of the different species can also be useful in many sponges. sponge identification. Several tools, such as posters 0 Dispersed collagen filaments – skeletal material and field guides, and designed to be used by found in all sponges non-specialist individuals while at sea have been 0 Spicules – inorganic elements present in almost developed. A selection of these is provided in the FAO all sponges’ skeleton and made of either calcium Vulnerable Marine Ecosystems webpage (www.fao. carbonate or silica. org/in-action/vulnerable-marine-ecosystems/ background/vme-tools/en/). New tools, including The composition, geometry and arrangement of the ones developed through SponGES will be these components can be diagnostic at different incorporated in the FAO VME webpage. SponGES has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 679849. This document reflects only the author’s view – the Executive Agency for Small and Medium- sized Enterprises is not responsible for any use that may be made of the information it contains. A selection of sponge identification tools DEEP–SEA SPONGES OF THE INDIAN OCEAN DEEP-SEA SPONGES OF THE MEDITERRANEAN SEA SPONGES SILICEOUS SPONGES – CLASS DEMOSPONGIAE GLASS SPONGES – CLASS HEXACTINELLIDA SPONGES SILICEOUS SPONGES – CLASS DEMOSPONGIAE GLASS SPONGES – CLASS HEXACTINELLIDA (PHYLUM Demosponges, also known as siliceous sponges, represent the largest and most diverse class within Porifera, comprising 85%, more than 6 600, of all sponge species. Their shape and size range from thin crusts, to various sizes Hexactinellids, also known as glass sponges, constitute a predominantly Demospongiae come in an enormous variety of shapes and sizes, from thinly encrusting masses, hemispheres, spheres, tiny globes and Hexactinellid glass sponges are unique amongst sponges in that they lack cell membranes and their silica spicules are based on a PORIFERA) of globular, vase-, cushion-, tree-like and giant barrels more than 2 m high. Coloration, derived from pigments or symbiotic associates, covers a wide spectrum (from white to black) including yellow, orange, red, blue, green, deep-sea group, typically occurring at bathyal and abyssal depths (i.e. below (PHYLUM lollipops, to large volcano-like forms several metres high. Others resemble flasks and tall tubes, or have fan and tree-like forms. Coloration hexagonal (six-rayed) design. Spicules may be extremely large as in a 'fishing-rod', or may be twisted into 'rope', fused into a network, or purple, brown, etc. Consistency depends on the skeletal composition and varies between soft, compressible, elastic, to tough and rock hard. The surface texture varies from smooth, velvety to rugose, and hispid. Approximately 200 m). They are exclusively marine and comprise approximately 675 species is derived from carotenoid pigments (purple, magenta, blue, brown, red, pink, orange, ochre and yellow), or due to the presence of form a soggy paper or rough sack-like fabric. Glass sponges are diverse in their shape: woven baskets and tubes, big sacks, fibreglass-like Sponges are amongst 670 demosponge species are known to occur in the Mediterranean Sea. worldwide, of which nine occur in the Mediterranean Sea. Their external PORIFERA) symbionts or specific metabolites. Texture reflects the underlying mineral (spicule) and organic (collagen, fibre) skeleton and may be matting, soft tulips on stalks, and hollow and solid coral-like sticks. Texture may be stony, softly papery, brittle, fragile; always non- the most ancient animals morphology usually varies between vase, blade, cup or tube-shaped and both Massive, hard sponges (Geodia spp.) Globular sponges with rooting structures (Thenea muricata) Lollipop sponges fleshy, woody, stony or fibrous. Demosponge skeletons may include spicules, sand grains, collagen and fibre, in various combinations. elastic. Coloration is muted, being translucent, white, cream, to faint pastel pinks and blues. to have appeared in the stalked and non-stalked forms exist. They attach to hard bottom using a basal Sponges are common disc or anchoring spicules, or to soft sediment by means of root-like structures. world’s oceans. Currently, Massive sponges Globular to egg- Lollipop-shaped invertebrates in the Monorhaphis chuni coming in a variety of shaped sponges sponges with Coloration is mostly in shades of white, beige and yellow. Ancorinidae species Cladorhizidae species Hyalonematidae species more than 8 000 species deep sea, providing shapes, from irregular with one or few a large, circular are recognized but over to convoluted masses; apical oscules. They (Stylocordyla Birds’ nest sponge (Pheronema carpenteri) habitat for certain 25 000 are estimated to younger specimens are are characterized pellita) to oval and usually (sub)spherical. by a distinct apically compressed Globular to sub- benthic fauna. exist. They are distributed Oscules are grouped groove around the (Rhizaxinella cylindrical sponges together and located mid-section of the pyrifera) “head” and possessing a wide and They attach to hard at all depths and latitudes, in depression areas body, where inhalant a slender stalk. One deep atrial cavity with and in some areas form located on the top pores (ostia) are substrate on oscule is visible at a large apical oscule. surface of the sponge. located, and root-like highly structured habitats the top of the head. The surface is “hairy” seamounts, Small inhalant pores structures projecting Thenea muricata Stelletta rugosa Stelletta sp. Ecionemia sp. Stelletta lithodes Abyssocladia sp. Asbestopluma sp. Chondrocladia spp. Hyalonema spp. Chalaronema sp. Dredged ‘glass rope’ Monorhaphis chuni Geodia barretti Geodia cydonium S. pellita, grey or Stylocordyla pellita Rhizaxinella pyrifera and shows an intricate known as sponge grounds, (ostia) are also grouped from the base, by hydrothermal vents, cream in colour, has a smooth and flexible stalk, and is attached to hard substrates by means of network of spicules. Size: ~ 10 to 40 cm Ø Depth: 1–2800 m Size: several mm high to ~ 30 cm high Depth: 60–2930 m Size: up to ~ 40 cm high Depth: 198–4077 m Size: 10 cm long (2 mm Ø) to 3 m long (1 cm Ø) Depth: 1567–2550 m aggregations, gardens or together but found distributed across the overall surface. G. barretti, cream in colour, has an even means of which they attach to soft substrate. Consistency is slightly compressible and texture is Texture is fibrous and and clean surface with a rubbery texture. G. cydonium, yellow in colour, has a hispid/harsh surface a rounded disc while R. pyrifera, dull yellow, has an occasionally knobbed or branched rigid stalk, pinnacles and canyons, smooth. Colour is white to brownish/greyish. compressible. It is Massive, flattened spherical to bowl-shaped sponges, with a smooth, granular or Feather-, tree-, sunflower- or lollipop-shaped 'carnivorous' sponges, with 'sticky' Tulip-shaped sponges with a large, cup-shaped to elongate body on a stem of glass Fishing rod-shaped sponge, comprising a single, massive spicule. A papery body clings reefs, particularly so in the often covered with sediment. Both species have a tough but slightly compressible consistency. and lives in soft sediment thanks to a branching root-like structure. hard corals, or anchor roughened, hairy surface. Oscules usually grouped at apex. Texture usually tough, filaments or balloon-shaped spheres on which living 'food' is caught. Attached by a threads, resembling a twisted rope that roots the sponge into sediment. Glass rope to the upper portion of the spicule that roots the sponge into soft sediment. Texture deep-sea. These habitats attached to the substrate incompressible. Skeleton dominated by harsh spicules that radiate internally and 'root' in soft substrate or by a rounded disc to hard substrate. Texture soft, often the only part collected. Texture of body soggy when wet, crisp and fibrous of body soggy when wet, fibrous and fragile when dry; easily detached. Colour of Size: up to 50 cm in diameter Depth