Foraminifera

The Foraminifera are single celled, mainly benthic, marine to brackish water protozoans that are amoeboid in shape (1A) but produce mainly calcareous tests (3 & 4) (some aggregate sediment particles in a hardened mucus (2)) through which extensions of the ectoplasm form parapodia (2, 3, 6 & 9).  These extensions are used for motility, anchoring to the sediment and to capture prey (diatoms and bacteria).  The taxonomy of this group is disputed as they are possibly grouped with radiolarians and cercazoans in the Infrakingdom Rhizaria.  All of these groups are important in carbon recycling as their tests sink carbon to the ocean floor from the atmosphere.

Radiolarians

Radiolarians are a group of marine protozoa (single celled eukaryotes) which have intricate siliceous skeletons (blue structures).  The skeletons both seperate the cell into two distinct inner and outer regions (7) (endo/ecto-plasm) and create long pseudopodia which increase surface area and aid in buoyancy.  The endoplasm usually contains the nucleus (n)  and other organelles whilst the ectoplasm often utilises gas filled vacuoles and lipid deposits to increase buoyancy (2).  The ectoplasm also often have symbiotic algae (Gz) which photosynthesise to produce food for the radiolarian (2 & 3).  The taxonomy of this group is disputed as they are possibly grouped with foraminiferans and cercazoans in the Infrakingdom Rhizaria.  All of these groups are important in carbon recycling as their tests sink carbon to the ocean floor from the atmosphere.

Ciliophora

The old phylum of Protozoa is recognised to be a paraphyletic group containing a diverse range of taxa grouped together only because of their simple body plan lacking complete tissues and being somewhat heterotrophic.  As such the clade Protozoa is now considered to be a paraphyletic kingdom containing meany phyla which are both related and un-related.  The phylum Ciliophora contains many large complex protozoans which utilise the beating of hair like structures called cilia to create movement of either themselves or the medium which carries their food to them.

Polychaete Worms

Vermes is an obsolete taxon used to group all non-arthropod invertebrates together.  Here the Class Annelides has now been promoted to the Phylum Annelida.  The order Polychaetae errantes is now classified as the Class Polychaeta.  The Annelida are the segmented worms (arguably some memberts have lost segmentation) with the polychaetes being the bristle-worms, both the formal and informal names refer to the many rigid bristles which extend from each segment’s parapodia.  This chart shows adult sand worms (1, 2, 3 & 9) but the group also include burrowing and tube building worms.  Annelids have a closed circulatory system which is highlited in the by the vessels (red), a partitioned through-gut (yellow) and cephalisation (concentration at the anterior end) of sensory organs (6 & 8).

Peanut Worms (Sipunculids and Echiurans)

The now obsolete taxon of Vermes once encompassed all non-arthropod invertebrates.  This wall chart compares two different phyla of worm; sipunculids and echiurans.  Both groups have previously been classified with in the Annelida despite their lacking the segmentation and bristled parapodia characteristic of this group. They are now both classified as seperate phyla within a group known as the Lophotrochozoa based on both larval development (14 & 15) and ribosomal DNA evidence.  A typical sipunculid (peanut worm) has an introvertible anterior region often with a crest of tentacles (1, 2, & 3). Different species burrow into sediments, rocks or calcified organic structures with the anterior end protruding. Echiurans are found in soft sediments with a long proboscis extending to the surface of the sediment where organic particles settle down onto a ciliated gutter which moves food to the mouth via the proboscis (10).

Brittle and Basket Stars

The Ophiuroidea are commonly known as brittle stars and basket stars.  They have a similar body plan to that of the Asteroidea (sea stars) with a central disk and five appendages radiating out.  Dissimilar to sea stars this group maintains a more strict adherence to pentaradial symmetry and all digestive organs remain within the central disk and almost never expand out into appendages.  Here the ventral (1) and dorsal (2) views of a typical central disk with the five calcereous jaws which lead to a blind ended gastrvascular cavity (stomach) can be seen.  Sections through the central disk at adult (4) and juvenile stages (7) are shown along with the respiratory organs called bursae (5 & 6, blue).  Also shown are the “ball and socket” vertebrae that make up the arms (8 – 11).

Sea Cucumbers, Sea Stars and Brittle Stars

This chart shows the early developmental stages of three classes of Echinoderm.  Holothuroidea are the class of sea cucumbers, Asteroidea the sea stars and Ophiuroidea the brittle stars.  Note the change in classification of brittle stars from within the Echinoidea (sea urchins) to an independent class within the same Subphylum which differentiates feather stars from all other Echinoderms.  Progressive development of an auricularian larva (from a sea cucumber) is shown (fig. 1-9) with it’s bands of cilia in place and adult tentacles forming (fig. 9).  Different stages of the bipinnaria larva of a sea star can be seen developing structures from gastrodermal and meso dermal tissue (fig. 10, 17 & 19). An ophiopluteus larva of a brittle star is shown forming it’s arms (fig. 11).

True Flies (Diptera)

The Diptera are known as the true flies and are characterised by one set of flying wings with the hind pair developed into halteres (II in 5), accelerometers which provide neural information on the orientation and changes to direction of the fly.  Flies are also characterised by the lack of chewing mouth parts, as they only consume liquid food sometimes by digesting it externally and sucking it up via a modified labelluma and labium (Lb in 9).

Parasitic Isopods

This chart appears to place a copepod (1) with parasitic representatives of the order Isopoda.  The Suborder Cymothoida and some other Isopod families parasitise as ectoparasites grazing on mucus and skin or as endoparasites sitting in the mouth/pharynx of a fish collecting food.  this chart shows some common body forms.  note how the legs are repeated at each segment compared to those of amphipods which are modified for different tasks on different segments (2-8).

Beetles II (Coleoptera)

The order with the most numerous species, the coleoptera make up about 40% of all insect species.  Known commonly as beetles their body plan doesn’t vary drastically within the order however homologous structures are often put to different uses.  This chart shows adult forms (5, 10, 14, 15 & 17) highlighting the segmentation of the body into the head (I), prothorax (II), mesothorax (III), metathorax (IV) and abdomen (V).  Two forms of larva are also illustrated; the scarabeiform larva (1) which usually reside within their food (eg. within a tree trunk) and the highly mobile elateriform larva (16) usually associated with ground dwelling and predatory forms.