Ducks, cranes and other aquatic birds abound in the delta.
Tadpoles are aquatic vertebrates.
The Spermatophyta are thus land plants par excellence and have, with the few exceptions cited, lost all trace of an aquatic ancestry.
In the aquatic, semi-aquatic, and xerophilous types, where the whole surface of the plant absorbs water, perpetually in the first two cases and during rain in the last, the hydrom strand is either much reduced or altogether absent.
A peculiar modification of periderm is formed by the phellogen in the submerged organs (roots or stems) of many aquatic or marsh-loving plants.
Found the most serviceable: - Hydrophytes (submerged aquatic plants) .Plants whose vegetive organs live wholly in water; e.g., most Algae, many mosses, ch as Fontinalis spp., and liverworts, such as Jungermannia spp.; few Pteridophytes, such as Pilularia spp., Isoetes spp.; several wering plants, such as Potamogeton pectinatus, Ceratophyllum p., Hottonia palustris, Utricularia spp., Liltorella lacustris.
In freshwater lakes and ponds, especially if the water is stagnant, aquatic plants are abundant.
Aquatic plants with submerged and floating leaves: Glyceria fluitans, Ranunculus peltatus, Nymphaea (Nuphar) - lutea, Callitriche stagnalis, Potamogeton polygonifolius.
Very few aquatic plants are pollinated under water, but this is wellknown to occur in species of Zostera and of Naias.
In the case of aquatic plants with aerial flowers, the latter obey the ordinary laws of pollination.
Insectivorous species occur among aquatic plants; e.g.
Seeds are carried in soil adhering to their feet and plumage, and aquatic plants have in consequence for the most part an exceptionally wide range.
In the Cathartae, in the Anseres, gulls, rails and various other aquatic birds.
Nature possesses three great educational or developmental schools - terrestrial, aquatic and aerial life.
Steganopodes.- Well flying, aquatic, nidicolous; with all the four toes webbed together.
Front toes completely webbed; hallux very short or absent; feed chiefly on small aquatic invertebrates.
The dace is a lively, active fish, of gregarious habits, and exceedingly prolific, depositing its eggs in May and June at the roots of aquatic plants or in the gravelly beds of the streams it frequents.
Two very small families of aquatic beetles seem to stand at the base of the series, the Amphizoidae, whose larvae are broad and well armoured with FIG.
20), for example - are specialized for an aquatic life, the body being convex and smooth as in the Dyticidae, and the intermediate and hind-legs fringed for swimming.
Many Hydrophilidae, unmodified for aquatic life, inhabit marshes.
The larvae of the beautiful, elongate, metallic Donaciae live in the roots and stems of aquatic plants, obtaining thence both food and air.
Numberless aquatic birds visit it for breeding purposes.
At Beaufort the United States Bureau of Fisheries has a marine biological laboratory, established in 1901 for the study of the aquatic fauna of the south-east coast.
The muscular layers are thinner in the aquatic forms, which possess only a single row of longitudinal fibres, or (Enchytraeidae) two layers.
In the aquatic genera the epidermis comes to consist entirely of glandular cells, which are, however, arranged in a single layer.
The prevalent number of testes is one pair in the aquatic genera and two pairs in earthworms. But there are exceptions; thus a species of Lamprodrilus has four pairs of testes.
The position varies in the aquatic Oligochaeta.