Today s plan. Molluscan Identification Workshop Mauritius Oceanography Institute October Matthew Kosnik

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1 Today s plan Molluscan Identification Workshop Mauritius Oceanography Institute October Matthew Kosnik

2 Task 1 Sort collection into numbered OTU (operational taxonomic units). These we hope are distinct species, when in doubt it is better to over split (easy to combined later, but harder to split later). Keep track of which OTUs you collected, but don t worry about which specimen you collected.

3 Task 2 Become familiar with bivalve morphology and identification. Use the Key to the higher taxa of bivalves from Oliver s Bivalved sea shells of the Red Sea to determine superfamily. Use relevant Superfamily s key to determine species. Work in groups of 2-3 (work with a stranger). The goal is to learn the morphology and terms used in classification and identification of bivalves!

4 Task 3 Each group - identify all of the bivalves we collected & write a description using the appropriate terms. I specifically want you to practice writing your own descriptions. Be as detailed and precise as possible. It is not a race, work at your own pace. Discuss and ask questions!

5 Google sheet [link removed] (( I ll that to everyone )) I recommend writing it out, then typing it in.

11 Class: Cephalopoda Molluscan Identification Workshop Mauritius Oceanography Institute October Matthew Kosnik

jpg Spirula spirula (Linneaus 1758) Very cool

12 Spirula Spirula spirula (Linneaus 1758) Very cool chambered shell with siphuncle. A tropical to subtropical deep sea species ( m). Not a whole lot is known about their biology, but the shells commonly wash up on beaches.

13 Class: Bivalvia Molluscan Identification Workshop Mauritius Oceanography Institute October Matthew Kosnik

14 Global diversity From Huber Compendium of Bivalves Volume 2. (Numbers of validly named living taxa, no extinct taxa) species 8360 marine species 93 marine families 4 subclasses

15 Mauritius diversity Based on Wells 2005, Shepard 1984, Michel 1988, Drivas & Jay 1988, and iobis.org with updated names: 306 distinct bivalve names used. 243 accepted species names. 148 accepted genus names. 43 accepted family names

16 Mauritius diversity Scientific No. English common French common M88 Pectinidae 37 Scallops Peignes 20 Veneridae 36 Venus shells Praires 32 Cardiidae 30 Heart cockles Coques 18 Tellinidae 25 No common name listed 26 Arcidae 22 Ark shells Arches 15 Mytilidae 18 Mussels Moules 13 Pteriidae 17 Perl shells Huîtres perlières 8 Lucinidae 16 Platter / moon shells None listed 14 Spondylidae 11 Thorny oysters None listed 7

17 Pictorial guide to bivalve families Lamprell and Whitehead Bivalves of Australia Volume 1 16

18 Pictorial guide to bivalve families Cardiidae Tridacninae 2 Lamprell and Whitehead Bivalves of Australia Volume 1

19 Pictorial guide to bivalve families Lamprell and Whitehead Bivalves of Australia Volume 1

20 Pictorial guide to bivalve families - 4 Lamprell and Whitehead Bivalves of Australia Volume 1

21 Pictorial guide to bivalve families Lamprell and Heally Bivalves of Australia Volume 2 22

22 Pictorial guide to bivalve families Lamprell and Heally Bivalves of Australia Volume 2 17

23 Pictorial guide to bivalve families Lamprell and Heally Bivalves of Australia Volume 2

24 Pictorial guide to bivalve families Lamprell and Heally Bivalves of Australia Volume 2

25 Pictorial guide to bivalve families Lamprell and Heally Bivalves of Australia Volume 2

26 Pictorial guide to bivalve families - 10 \ 2 2 Lamprell and Heally Bivalves of Australia Volume 2

27 Pictorial guide to bivalve families Lamprell and Heally Bivalves of Australia Volume 2

28 Bivalve shell morphology

29 Orientation Hinge is always dorsal. Ligament is posterior of umbo/beak (if to one side). Pallial sinus - always posterior (if present). Byssal notch - always anterior (if present). The posterior muscle scar is usually bigger.

30 Nomenclature: General Oliver Bivalves of the Red Sea

31 Nomenclature: Shell shape Oliver Bivalves of the Red Sea

32 Nomenclature: Hinges, Ligaments and Muscles Oliver Bivalves of the Red Sea

33 Nomenclature: Radial sculpture Oliver Bivalves of the Red Sea

34 Nomenclature: Concentric sculpture Oliver Bivalves of the Red Sea

35 Nomenclature: Complex & inner margin sculpture Oliver Bivalves of the Red Sea

36 Nomenclature: General & measurements Wilson A handbook to Australian seashells

37 Bivalve descriptions

38 Example: Taxonomic

39 Example: Taxonomic

40 Example: Guidebook Anadara antiquata (L.) Up to 7 cm wide. Extended and rounded posterior with a straight hinge line and many fine teeth; about 32 strong, radiating ridges and interlocking crenelated margins. Colour white with a dark brown periostracum. Habitat: eulittorial, buried in muddy sand. They resemble the genus Arca (which have more elongate shells). (Richmond 1997)

41 Describing bivalves Name [Most obviously to least obvious in a sensible way] Size, shape, hinge, muscle scars, ornament Points of difference from similar species. References used.

Shell 20267 (mmol/mol) 3.0 2.5 2.0 1.5 1.0 0.5 0.0 0.03 0.02 0.01 0.00 Mg/Ca 0.

42 Shell (mmol/mol) Mg/Ca 0.04 Ba/Ca 10 Sr/Ca 8 6 Callisa disrupta growth lines and shell chemistry Dominguez Submitted PhD Thesis Distance (mm)

43 Size Molluscs mostly have indeterminate / asymptotic growth so we tend to measure the biggest specimen that we can find Age (yrs) Shell length (mm) L = 44 ± 3 K = 0.3 ± 0.1 Callista disrupta age / size relation Dominguez Submitted PhD Thesis

Guide to Families 29 BIVALVES TECHNICAL TERMS AND MEASUREMENTS. Dorsal margin. posterior adductor muscle scar lateral tooth

Guide to Families 29 BIVALVES Coastal species are of great interest to fisheries and have potential for exportation for eating purposes. Bivalves are caught mainly by divers and are also fished for pearls.