The tentacle-bearing, sessile hydroids and bryozoa are not closely related. They are both easily overlooked because they are small (hydro...
Most of the molluscs found in NZ streams or ponds belong to one of the groups shown below. When identifying snails, the terms “left-hande...
The Oligochaeta includes the well-known earthworms and many small species of freshwater worms. They are part of the Phylum Annelida; the ...
Sponge-like growth attached to the bed with no feeding tentacles
Is it maggot-like with a distinct head, or breathing tube, or fleshy prolegs, or disc supporting fleshy lobes at the end of the body?
There are four very different groups of unsegmented freshwater worms. They range from the almost invisibly tiny nematodes to the gordians...
![The green [Chlorohydra]. Image: Stephen Moore](/assets/Tools-And-Resources/Identification/freshwater-invertebrates/hydra_chlorohydra_b_650__FillMaxWzMwMCwyMDBd.jpg)
![Mud snail [Potamopyrgus antipodarum]. Image: Stephen Moore](/assets/Tools-And-Resources/Identification/freshwater-invertebrates/potamopyrgus_mwh_manguika_oct_2010_38xmontage_b_650__FillMaxWzMwMCwyMDBd.jpg)
![Sponge on [Potamopyrgus] snail. Image: Stephen Moore](/assets/Tools-And-Resources/Identification/freshwater-invertebrates/sponge_on_potamopyrgus_kml_rdc_us_1-3_18-1-0633xmontage_b_65-1__FillMaxWzMwMCwyMDBd.jpg)
![Midge [Chironomus]. Image: Stephen Moore](/assets/Tools-And-Resources/Identification/freshwater-invertebrates/chironomus_red_cmontage_b_650_na__FillMaxWzMwMCwyMDBd.jpg)
![[Neppia]. Image: Stephen Moore](/assets/Tools-And-Resources/Identification/freshwater-invertebrates/neppia_dingle_brook_huia_aug_07f_b_650_na__FillMaxWzMwMCwyMDBd.jpg)