Phylum: Brachiopoda

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PHYLUM: BRACHIOPODA

xxx mm xxx mm

Distinguishing features xxx Authors Colour xxx Lara Atkinson1 and Norton Hiller2 Size xxx Citation Distribution xxx Atkinson LJ and Hiller N. 2018. Phylum Brachiopoda In: Similar speciesAtkinson LJ and Sink KJ (eds) Field Guide to the Ofshore Marine Invertebrates xxx of South Africa, Malachite Marketing and Media, Pretoria, pp. 245-248.

References xxx

1 South African Environmental Observation Network, Egagasini Node, Cape Town 2 Canterbury Museum, Christchurch, New Zealand

245 Phylum: BRACHIOPODA

Lamp shells

Brachiopods are exclusively marine, sessile and the valves are opened and closed using two sets invertebrates ranging in size from 1-100 mm in of muscles (diductors and adductors respectively) length. They consist of two unequal hard valves to allow feeding to take place. In the inarticulated (shells) enclosing the soft tissues dorso-ventrally brachiopods (linguliforms and craniiforms), the instead of laterally, as in bivalves. valves do not have a hinge mechanism and are opened and closed by a complex system of muscles. Brachiopods are a relatively minor group in modern oceans but occupy a wide range of habitats, from Although brachiopods were once thought to be intertidal rocky shorelines to abyssal depths, with unimportant prey items, there is a growing body the majority of species occurring on continental of evidence to suggest they may be preyed upon shelves. They are distributed from equatorial to polar by a range of predators, including crustaceans, waters, and may be locally abundant. Most species echinoderms, gastropods and ish. Many specimens avoid areas with strong currents and waves and show holes drilled in the shell by predators and/or prefer to live in habitats such as rocky overhangs, parasites. However, there is debate as to whether caves, crevices and in deep waters (i.e. cold with brachiopods were the preferred, or intended prey low light). Globally, approximately 391 species in observed instances. of brachiopods are known with about 30 species (15 endemic) reported in South Africa. References Most live epifaunally, attached by a leshy stalk (or Bitner MA and Cohen BL 2013. Brachiopoda. pedicle), which exits the shell through a foramen In: Encyclopedia of Life Sciences. John Wiley in the larger ventral valve, to a hard substrate, such & Sons, Ltd. DOI: 10.1002/9780470015902. as rock or other shells. Some forms actually cement a0001614.pub3 one valve to the hard substrate, while others are Branch GM, Griiths CL Branch ML and adapted to live on a soft sea loor and are essentially Beckley LE. 2016. Two Oceans. A guide to the free-living. One unusual form lives in a burrow (not marine life of southern Africa. Fourth Edition. addressed further in this guide). Struik Nature, Cape Town. p.144.

Like bivalve molluscs, brachiopods have two shells, Emig CC, Bitner MA and Álvarez F. 2013. or valves, that enclose and protect the soft body Phylum Brachiopoda. In: Zhang, Z.-Q. (Ed.) tissues. In a relatively large mantle cavity, the feeding Animal biodiversity: An Outline of Higher- organ (the lophophore) uses ciliated tentacles to level Classiication and Survey of Taxonomic ilter food from sea water. The lophophore and the Richness (Addenda 2013). Zootaxa, mantle also play a vital role in absorbing oxygen 3703, 75–78. http://dx.doi.org/10.11646/ and eliminating carbon dioxide. Most brachiopods zootaxa.3703.1.15 possess a shell composed of calcium carbonate but Harper, E.M., 2011. What do we really some forms have a shell made of calcium phosphate. know about predation on modern rhynchonelliforms? Memoirs of the In the articulated brachiopods (rhynchonelliforms), Association of Australasian Palaeontologists the two valves are hinged at the posterior end. Teeth 41, pp. 45-57. in the ventral valve it into sockets in the dorsal valve

246 Phylum: Brachiopoda

Megerlina capensis (MegCap)

Phylum: Brachiopoda

Class: Rhynchonellata

Order: Terebratulida

Family: Kraussinidae

Genus: Megerlina

Species: capensis

Common name: Ribbed Lamp shell

Dorsal view Ventral view Ventral view

Foramen Posterior (pedicle opening)

15 mm 18 mm

Distinguishing features frequently have the posterior end abraded by Small rounded sub-pentagonal to sub-quadrate close attachment to a rocky substrate resulting in shells with length and width about equal. Ventral enlargement of the pedicle opening. valve (shell) slightly deeper than dorsal valve. Anterior commissure (line along which the valves References meet, viewed from the anterior) gently sulcate (i.e. Hiller N. 1986. The South African Museum’s Meiring with a broad U-shaped delection). Relatively large Naude cruises. Part 16. Brachiopoda from the 1975– pedicle opening bounded laterally by small, lat, 1979 cruises. Annals of the South African Museum triangular inter-areas. Fine concentric growth lines 97:97-140. and 24-33 rounded radial ribs visible exteriorly from Hiller N. 1994. The environment, biogeography, and the 5-mm growth stage. origin of the southern African Recent brachiopod fauna. Journal of Paleontology 68:776-86. Colour Usually pinkish or reddish but may be white or Hiller N, MacKinnon DI and Nielsen SN. 2008. A review cream, sometimes with red margins. of the systematics, biogeography and evolutionary relationships of recent and fossil brachiopods of the Size Superfamily Kraussinoidea Dall, with descriptions Usually not more than 15 mm in length. of two new fossil species from New Zealand and Chile 379-390. In CUSACK, M. & HARPER, D.A.T. (eds) Distribution Brachiopod Research into the Third Millenium. Earth and Environmental Science Transactions of the Royal West, South and East Coasts of South Africa. Society of Edinburgh 98. Similar species Jackson, J. W. 1952. A revision of some South African Looks most like the shallower water form Kraussina Brachiopoda; with descriptions of new species. rubra (Pallas, 1766) but this can be distinguished Annals of the South African Museum 41:1-40. by its larger size and coarser ribbing. Specimens

247 Phylum: Brachiopoda

Xenobrochus sp. (Xenobr)

Phylum: Brachiopoda

Class: Rhynchonellata

Order: Terebratulida

Family: Dyscoliidae

Genus: Xenobrochus

Species: sp.

Common name: Smooth Lamp shell

Dorsal view

Posterior

Pedicle

11 mm

Distinguishing features waters apart from others in the genus. Specimen Small, elongate oval, strongly biconvex shells. Ventral shown in photograph on this page most likely valve (shell) deeper than dorsal valve. Anterior Xenobrochus agulhasensis. Gryphus capensis Jackson, commissure (line along which the valves meet, 1952 (not shown in this guide) is supericially similar viewed from the anterior) straight (rectimarginate). but difers in the form of the internal structures of Pedicle opening small, sub-circular. Shell surface the dorsal valve. smooth except for ine concentric growth lines. Shell material very thin. References Hiller N. 1986. The South African Museum’s Meiring Colour Naude cruises. Part 16. Brachiopoda from the 1975– White. 1979 cruises. Annals of the South African Museum 97:97-140. Size Hiller N. 1994. The environment, biogeography, and Usually around 11 or 12 mm in length. origin of the southern African Recent brachiopod fauna. Journal of Paleontology 68:776-86. Distribution Jackson, J. W. 1952. A revision of some South African West, South and East coasts of South Africa. Brachiopoda; with descriptions of new species. Similar species Annals of the South African Museum 41:1-40. The small size and smooth shell readily distinguishes this species from most others known in South African

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