A new genus and species of mesoparasitic ergasilid (Copepoda: Cyclopoida) from brackish water pufferfishes collected in northern Australian waters.

A new mesoparasitic ergasilid copepod, Majalincola buthi n. g., n. sp., is described based on material collected from the gills of Marilyna darwinii (Castelnau) and M. meraukensis (de Beaufort) (Tetraodontidae) captured in brackish waters in northern Australia. The new genus is characterised by the presence in the fully-transformed adult female of: four tagmata (antennary, neck, postantennary cephalothoracic region and trunk region); a 5-segmented antennule; a trimerous leg 1 endopod; and a free exopod segment armed with two setae on the fifth leg. The establishment of the new genus is supported by the results of a cladistic analysis of Majalincola and members of its sister taxon.

A new species of Malmiana (Oligochaeta: Hirudinida: Piscicolidae) from tidepool fishes in northern California.

Malmiana buthi n. sp. is described from the body and fins of the fluffy sculpin, Oligocottus snyderi, the tidepool sculpin, Oligocottus maculosus, and the woolly sculpin, Clinocottus analis, collected from tidepools at Horseshoe Cove on the Bodega Marine Reserve in Sonoma County, California. Prevalence of the leech was 32.6% on live-caught O. snyderi; mean intensity on O. snyderi was 3.3 leeches per fish, with a range from 1 to 7. The leech is not known to exceed 8 mm total length. The body is smooth, lacking papillae, tubercles, or pulsatile vesicles. Two pairs of crescentiform eyes are present on the oral sucker, and 1 pair of punctiform eyes occurs on the second annulus of the trachelosome. The caudal sucker has 14 small punctiform ocelli spaced evenly around the margin. The last 9 segments of the urosome have pairs of large punctiform ocelli both dorsally and ventrally. Body and caudal sucker pigmentation is uniformly reddish brown dorsally and ventrally with segental, lateral, unpigmented areas on both the urosome and trachelosome; pigmentation on the oral sucker is in the form of a cross. There are 5 pairs of testisacs; accessory gland cells on the atrial cornua and vector tissue are absent.

New caligiform Copepod (Siphonostomatoida: Dissonidae) parasitic on Seriola hippos from western Australian waters, with new records and orphological variation for Dissonus nudiventris and Dissonus similis, and an updated key to the species of Dissonus.

Dissonus hoi n. sp. is described from female and male specimens collected from the nasal cavities of a Samson Fish (Seriola hippos Günther) captured off Rottnest Island, Western Australia. Adult female D. hoi are distinguished from their congeners by possessing the following combination of characters: (1) a quadrangular genital complex, (2) ventral spines on the genital complex, (3) pair of postantennal processes, (4) a sternal furca, (5) 1-segmented abdomen, and (6) convoluted, uniseriate egg strings. New records and intraspecific morphological variation are also given for Dissonus nudiventris collected from Australia, and Dissonus similis collected from the tropical western Pacific. A key to the valid species of Dissonus is provided.