Examples of at least four different genera once grouped together within the order Copepoda. Now these genera diverge after the class level into too sub classes Branchiura and Copepoda as sister taxa to barnacles. Care must be taken when analysing these Subclasses relatedness as the class Maxillopoda may not be a monophyletic group.
The freshwater crayfish genus Astacus is used to illustrate the internal anatomy of the now obsolete order Thoracostraca which comprised all shrimp, lobster and crayfish. Internal structures are colour coded where red represents the open circulatory system, yellow the digestive system and blue the ventral nerve cord and associated ganglia. Among the illustrations are an entire vertical longitudinal section (1), cross section through the thoracic region (2), the shape of various paired appendages (3), dorsal view of a dissected anterior region of alimentary canal (4), the network of vessels mixing the open circulatory system (5), the male (6) and female (7) reproductive organs, section of a compound eye (8) and structure of antennule with auditory structure labelled (9).
A species of freshwater crayfish formerly common through out streams and brooks of western and northern Europe. Dissection on the left shows the heart (central red structure) with blood vessels (also red), muscle blocks (anterior pink ovals), and Liver (brown elongate structures in thoracic cavity). Dissection on the right shows the cardiac portion of the stomach (anterior blue structure with “T” shape in it), the pyloric section of the stomach (narrowing part of blue structure), the caecum (brown bulb immediately posterior to pyloric stomach), hind gut (long brown canal in abdomen) and again livers (paired brown structures on either side of alimentary canal.
Internal and external morphological features of a female oriental cockroach. A subset of the abbreviations are as follows: mandible (Mn), maxilla (Mx), labial palp (Lbi.p), maxillary palp (Mx.p), eye (E), cerebral ganglion (C.G), salivary glands (S.Gl), ventral ganglion (V.G), crop (Cr), gizzard (Gz), pyloric caeca (Py.C), malpighian tubule (M.Tb), rectum (R), ovipositor (O), vagina (Va), oviduct (Ovd).
Different larval stages of a range of different decapods. Because of their complex life history many of the larval stages of different taxa were originally classified together as groups of their own. Some lobster species have over twenty different larval stages. Examples that are of note on this chart are the nauplius (1) of copepods, the zoea (10 & 11) of crabs, and the phyllosoma (3) of lobsters.
Adult (1, 2, 9, 10 & 11) and larval (12 & 13) representatives of plant parasitising wasps and ants of Hymenoptera. Structures on plants are galls which are large deformations of plant tissue induced to grow once a female lays eggs into the plant tissue. These galls provide nutrients and protection for larvae however, these larvae are often hyper-parasitised by other hymenopterans, sometimes of the same family.
External appearances through complete metamorphosis of more derived Hymenopteran representatives showing: Maggot-like larval stages (1, 5 & 6), an inactive pupal stage (2), adult forms (3, 4 & 7) and early developmental stages (9-13). The parasatoid life history of many Hymenopteran wasps is represented (6).