Nerocila
Nerocila is a genus of parasitic isopods in the family Cymothoidae, commonly known as fish lice. These crustaceans are ectoparasites, meaning they live on the external surface of their hosts, which are typically fish. The genus comprises approximately 13 species, primarily found in marine environments worldwide.
Characteristics
Nerocila species are characterized by their flattened, elongated bodies, which are adapted for clinging to the skin and scales of their hosts. They possess seven pairs of legs, the first pair of which is modified into powerful claws for grasping and holding onto their host. These isopods typically range in size from a few millimeters to several centimeters in length, with their bodies being segmented and covered in a tough exoskeleton.
Like other cymothoids, Nerocila species are sexually dimorphic, meaning that males and females exhibit distinct physical characteristics. The males are typically smaller than the females and possess a pair of elongated antennae. The females, on the other hand, are larger and have a brood pouch on their ventral surface, where they carry their eggs.
Environments
Nerocila isopods are found in various marine habitats, including coastal waters, reefs, and open oceans. They exhibit a wide geographical distribution, with species being found in tropical, subtropical, and temperate regions around the world. Their primary hosts are bony fishes, although some species have been observed to parasitize sharks and rays.
Parasitic Lifestyle
Nerocila isopods are obligate parasites, meaning they require a host to survive. Once they locate a suitable host, they use their claws to attach themselves to the skin, often near the gills or fins. They then feed on the blood and tissues of their host, causing damage and potential illness.
The parasitic lifestyle of Nerocila species can have significant impacts on their hosts. Infections can lead to anemia, weakness, and even death in some cases. The presence of these parasites can also interfere with the host's ability to swim, feed, and reproduce.
Species
The genus Nerocila comprises approximately 13 recognized species, including:
- N. acuminata
- N. bivittata
- N. capensis
- N. clausi
- N. dendrobranchiata
- N. excavata
- N. fluviatilis
- N. longispina
- N. maculata
- N. mediterranea
- N. monocanthi
- N. obtusa
- N. ornata
References
World Register of Marine Species
A new species of Nerocila (Cymothoidae, Isopoda) from the South Atlantic Ocean