14 - Systematics of Intertidal Fishes

Over 70 species of intertidal fishes from 12 families breathe air while emerging from water. Amphibious intertidal fishes generally have no specialized air-breathing organ but rely on vascularized mucosae and cutaneous surfaces in air to exchange both oxygen and carbon dioxide. They differ from air-breathing freshwater fishes in morphology, physiology, ecology and behaviour. Air breathing and terrestrial activity are present to varying degrees in intertidal fish species, correlated with the tidal height of their habitat. The gradient of amphibious lifestyle includes passive remainers that stay in the intertidal zone as tides ebb, active emergers that deliberately leave water in response to poor aquatic conditions and highly mobile amphibious skipper fishes that may spend more time out of water than in it. Normal terrestrial activity is usually aerobic and metabolic rates in air and water are similar. Anaerobic metabolism may be employed during forced exercise or when exposed to aquatic hypoxia. Adaptations for amphibious life include reductions in gill surface area, increased reliance on the skin for respiration and ion exchange, high affinity of haemoglobin for oxygen and adjustments to ventilation and metabolism while in air. Intertidal fishes remain close to water and do not travel far terrestrially, and are unlikely to migrate or colonize new habitats at present, although in the past this may have happened. Many fish species spawn in the intertidal zone, including some that do not breathe air, as eggs and embryos that develop in the intertidal zone benefit from tidal air emergence. With air breathing, amphibious intertidal fishes survive in a variable habitat with minimal adjustments to existing structures. Closely related species in different microhabitats provide unique opportunities for comparative studies.

Ecology of intertidal fishes of the Southeastern Pacific Ocean: A review

While the syntopic nature of many intertidal fish communities suggest that resources such as food are shared, little has been done to assess the importance of diet on the coexistence of intertidal fish of the U.K. In this study, six intertidal fish species (shanny, Lipophrys pholis, Blenniidae; long-spined scorpion fish, Taurulus bubalis, Cottidae; two-spotted goby, Gobiusculus flavescens, Gobiidae; rock goby, Gobius paganellus, Gobiidae; plaice, Pleuronectes platessa, Pleuronectidae; butterfish, Pholis gunnellus, Pholidae) were collected from two sites along the east coast of England (Filey and Thornwick Bay) and two sites around the coast of the Isle of Anglesey, North Wales (Rhosneigr and Penrhos), during summer and winter. A comparison of the diets of those in the highest abundances (L. pholis, T. bubalis and G. flavescens) found that, in general, prey preferences were dissimilar between species, albeit with some slight overlap, and therefore it could be said that diet acts as an important mechanism of interspecific coexistence.

Hypoxic conditions are rare in the open ocean, but may occur during low tides in tidepools. Intertidal fishes respond to low tides in a variety of ways, including avoiding the intertidal zone during low tides, respiring in the well-oxygenated layer at the surface of the water, or simply tolerating hypoxic water. A number of intertidal fish species have the ability to leave the water and survive terrestrially for a period of time while breathing air. This paper reviews the literature on ecomorphology of amphibious intertidal fishes, suggests ecomorphological and ecophysiological approaches to clarifying the adaptations of intertidal fishes for emergence from water, and considers differences in the types of emergence behavior and activities seen in three broadly defined behavioral types. These types include the ‘skippers’, fishes that actively emerge at all phases of the tidal cycle and engage in routine terrestrial activity, the ‘remainers’, that emerge passively under cover such as rocks or vegetation by remaining in place as the tide recedes, and the ‘tidepool emergers’, that typically spend low tides in tidepools but may emerge from hypoxic water. Portioning of gas exchange between the gills and the skin, the release of CO2 into air, the effect of emergence on metabolic rate, and vertical zonation in distribution of fishes in the intertidal zone are compared for fishes in each of these behavioral styles.

Spatial and temporal variations in the species composition of assemblages are common in many marine organisms, including fishes. Variations in the fish species composition of subtidal coral reefs have been well documented, however much less is known about such differences for intertidal fish assemblages. This is surprising, given that intertidal fishes are more vulnerable to terrestrial human disturbances. It is critical to evaluate the ecology and biology of intertidal fishes before they are severely impacted by coastal development, especially in developing countries such as those in the tropical western Pacific region where coastal development is rapidly increasing. In this study, we investigated the species composition, abundance, biomass and species number (richness) for intertidal fish assemblages in subtropical (northern) and tropical (southern) Taiwan across four seasons by collecting fishes from tidepools using clove oil. We also examined the gut contents of collected fishes to identify their trophic functional groups in order to investigate regional and seasonal variations for different trophic groups. We found significant differences in the species composition of tidepool fish assemblages between subtropical and tropical Taiwan. Bathygobius fuscus, Abudefduf vaigiensis and Istiblennius dussumieri were dominant species in subtropical Taiwan, whereas Bathygobius coalitus, Abudefduf septemfasciatus and Istiblennius lineatus were dominant in tropical Taiwan. Other species such as Bathygobius cocosensis, Abudefduf sordidus and Istiblennius edentulus were common in both regions. For trophic groups, omnivores and detritivores had or showed trends towards higher species numbers and abundances in the subtropical region, whereas herbivores, planktivores and general carnivores had or showed trends towards higher species numbers and biomass in the tropical region. Overall, many intertidal fish species and trophic groups showed differences in abundance, biomass and species number between subtropical and tropical Taiwan. Further studies on large scale geographical gradients in trophic groups and species compositions in the Indo-west Pacific region are encouraged to assist with ecosystem monitoring and assessment. Keywords: Intertidal fishes, spatio-temporal pattern, feeding guild, diet

4 - Respiration in Water and Air

The intertidal environment may be characterized by extreme changes in water temperature, pH, salinity, oxygen and carbon dioxide tensions, and these may occur on a daily basis or be influenced by season or by the prevailing weather conditions. Temperature, osmoregulatory and respiratory problems may also be exacerbated by aerial exposure in some intertidal fish species. This brief review will concentrate on temperature, osmotic, respiratory and metabolic adaptations of intertidal fish which enable them to survive and colonize this extreme environment. Gibson (1982) has defined an intertidal fish as “a species which relies on utilization of the intertidal zone for completion of all or an essential part of its life history”. This definition will therefore be used throughout the chapter.

15 - Biogeography of Rocky Intertidal Fishes

This paper presents a comparative analysis of territoriality in three intertidal (Lipophrys pholis, Coryphoblennius galerita, Salaria pavo) and two subtidal (Tripterygion delaisi, Parablennius pilicornis) blennioid fishes. Focal-animal observations of males guarding eggs showed that: (i) intertidal species had smaller territories that were less frequently patrolled; (ii) in subtidal species feeding was limited to the territory, while in intertidal fishes a substantial proportion of the feeding acts occurred outside the defended area; (iii) intertidal species spent less time out of the nest and showed a lower level of locomotory activity; (iv) subtidal species were subjected to a higher number of territorial intrusions with more species intruding their territory, some of them potential egg predators; (v) subtidal species performed several water column displays that played a significant role in courtship, while in intertidal fishes these displays are almost absent. Signalling without the presence of a female was almost absent in intertidal species. It is argued that intertidal fishes minimize the time spent out of the nest and the loss of contact with the substrate, features that may be of high survival value in conditions of strong turbulence. Although intertidal species have a reduced time available for feeding, this may be compensated by lower levels of locomotory activity, territorial defense and risk of egg predation.

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 383:273-283 (2009) - DOI: https://doi.org/10.3354/meps07986 Intertidal and subtidal blennies: assessment of their habitat through individual and nest distribution Alessandro Duci, Eva Giacomello, Nicole Chimento, Carlotta Mazzoldi* Department of Biology, University of Padova, Via U. Bassi 58/B, 35131 Padova, Italy *Corresponding author: Email: carlotta.mazzoldi@unipd.it ABSTRACT: Resident and transitory intertidal fish species are expected to differ in their utilization of space in the intertidal zone. Here we assessed fish zonation patterns on 2 rocky shores of the northwestern Adriatic Sea (where tides can range up to 1.5 m) using blennies as study species and distribution of both individuals and nests as methodological tools. Of the 12 species observed, 5 were found exclusively in the intertidal zone: Aidablennius sphynx, Coryphoblennius galerita, Lipophrys adriaticus, L. canevae and L. dalmatinus. Two species, Parablennius rouxi and P. tentacularis, were found only in the subtidal zone, whilst P. gattorugine, P. incognitus, P. sanguinolentus, P. zvonimiri and Salaria pavo were observed in both environments. Nest distribution mirrored individual distribution, strongly indicating that some blenny species can be considered true intertidal residents, spending the main part of their lives in this area. Intertidal and subtidal species showed different patterns of space utilization. Indeed, the former nested higher in the vertical distribution than the average depth at which individuals were recorded, and the latter, despite visiting the intertidal area at high tide, always nested below the minimum water line. These results show that, contrary to theoretical predictions, intertidal-resident fish may fully exploit intertidal habitats, for foraging and for reproduction, occupying even the sectors most distal from the subtidal zone, i.e. the most variable in terms of physical conditions. Moreover, nest distribution was found to be an effective measure of residence and thus a useful referent to evaluate space use in intertidal fish. KEY WORDS: Blenniidae · Nest · Eggs · Intertidal fish · Vertical zonation · Adriatic Sea Full text in pdf format PreviousNextCite this article as: Duci A, Giacomello E, Chimento N, Mazzoldi C (2009) Intertidal and subtidal blennies: assessment of their habitat through individual and nest distribution. Mar Ecol Prog Ser 383:273-283. https://doi.org/10.3354/meps07986 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 383. Online publication date: May 14, 2009 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2009 Inter-Research.

A new species, Hemipera cribbi sp. nov., is described. This trematode was found in three intertidal fish species: Scartichthys viridis (Valenciennes) (Blenniidae), Gobiesox marmoratus Jenyns (Gobiesocidae) and Myxodes viridis Valenciennes (Clinidae) from the central and southern coast of Chile. Of 233 individuals of S. viridis from the central coast examined, 19 were infected. From the southern coast, nine individuals of S. viridis (one infected), five individuals of G. marmoratus (four infected), and 16 individuals of M. viridis (one fish infected) were examined. Hemipera cribbi sp. nov. is distinguished from the five other congeneric species mainly in the body size, being the smallest and narrowest species in the genus, reaching five times longer than wide. This is the first species of the genus described for the South Pacific Ocean off South America. ITS2 rDNA sequences of Hemipera cribbi sp. nov. from each host and locality were identified.

The effect of UV radiation on habitat use of two species of intertidal fishes that inhabit the same pools but exhibit different activity levels and diets was measured: the highly active omnivorous Girella laevifrons and the cryptic carnivorous Graus nigra. Individuals of each species were acclimated to a tank divided in three sections with different illumination; no light (NL), ultraviolet light (UV) and white light (WL), and the time spent and number of visits to each section were recorded. Although both species preferred the NL section, G. laevifrons spent more time in UV and less time in WL compared with G. nigra; G. laevifrons also displayed higher number of visits to UV, suggesting a different tendency in space use in response to UV exposure in intertidal fishes.

2 - Methods for Studying Intertidal Fishes

Daily deposition of otolith increments was validated for juveniles of 8 intertidal fish species in central Chile, Helcogrammoides chilensis, Helcogrammoides ...

Intertidal Fishes