Lepidoblennius

Abstract: This paper provides the first large-scale data of the rockpool ichthyofaunas of southeastern New South Wales (NSW), Australia, and compares the fish assemblage structure of this region with other regions in Australia and the world. A range of studies undertaken between August 1999 and September 2001 at 14 locations yielded 14,225 fish comprising 50 species from 26 families. About 64% of species were endemic to Australia, 30% have an Indo-Pacific distribution, while 6% have a trans-Tasman distribution. The dominant families were Gobiidae (4836 fish, four species), Tripterygiidae (3589 fish, three species) and Clinidae (1672 fish, five species). Permanent rockpool residents comprised 85% of assemblages (Bathygobius cocosensis, Enneapterygius rufopileus and Lepidoblennius haplodactylus), opportunistic temporary residents comprised 14% (Girella elevata) and the remaining 1% comprised seasonally abundant transients (Chaetodon auriga and Kuhlia mugil). Fish assemblages in the present study were similar to other rockpool fish assemblages in northern NSW, although latitudinal variation was evident with a gradual replacement of temperate fishes with those of a tropical origin. On a global scale, Australian rockpools support unique ichthyofaunas but the dominant families (Blenniidae, Tripterygiidae, Gobiidae, Gobiesocidae and Clinidae) are similar to those in many countries of Gondwanan origin, such as Chile, Portugal, New Zealand and particularly South Africa where some species are even shared. Rockpools in countries of Laurasia origin (United States, Mexico, and Canada) support very different fish assemblages mainly representing the families Cottidae, Stichaeidae, Scorpaenidae and Pholidae. This probably represents speciation of rockpool fishes since separation of these landmasses in geological time, which may be driven by limited larval dispersal and colonisation of some species in specific regions.

Abstract: In the present work we describe nine saccular otolith morphometric indices (circularity, rectangularity, aspect ratio, percentage of the otolith surface occupied by the sulcus, percentage of the sulcus length occupied by the cauda length and ostium length, otolith length relative to the length of the fish, rostrum aspect ratio and percentage of the rostrum length occupied by the otolith length) of 41 species of the Tripterygiidae family collected mainly from New Zealand, Australia, Chile, South Africa, Mediterranean Sea and North America. The principal component of analysis showed that the indices that best explain the variability between species were related to sulcus and rostrum morphometry. According to cluster analysis, otolith morphometry could reflect the diversity of microenvironments for some genera such as Notoclinops and Forsterygion, while this does not happen to genera like Enneapterygius and Ruanoho. The discriminant analysis showed that the species Helcogrammoides cunninghami, Karalepis stewarti, Lepidoblennius haplodactylus, Notoclinus compressus, Ucla xenogrammus can be discriminated by using the morphometric indices. Two new indices related to the sulcus that were of great value for the discrimination of these species are described for the first time. This information will be a useful tool for palaeontological, taxonomic and trophic ecology studies.