Anthony J. Booth

Rhodes University | RU · Department of Ichthyology and Fisheries Science

The availability of appropriate refugia may ameliorate some impacts of habitat degradation and can aid in the conservation of target species. In addition to natural refugia, the provision of artificial refugia may be viable, particularly in degraded habitats. We examined the conservation potential of natural and artificial refugia for the endangere...

Stable isotope mixing models are regularly used to provide probabilistic estimates of source contributions to dietary mixtures. Whilst Bayesian implementations of isotope mixing models have become prominent, the use of appropriate diet-tissue discrimination factors (DTDFs) remains as the least resolved aspect. The DTDFs are critical in providing ac...

en When exposed to predator cues, ostariophysan fishes exhibit short‐term anti‐predator behavioural responses in order to minimise predation risk. Non‐native predator cues are, however, likely to elicit poor behavioural responses in native prey fishes. This study investigated whether chubbyhead barb Enteromius anoplus , a native freshwater minnow i...

We examined innate responses to conspecific and heterospecific alarm cues in a small cyprinid minnow, the Eastern Cape redfin Pseudobarbus afer. We found that redfins respond to conspecific skin extract, which contains alarm chemicals, and showed that their preferred response is to hide in refugia. Redfins also respond to skin extract from an allop...

To test ecological niche theory, this study investigated the spatial patterns and the environmental niches of native and non‐native fishes within the invaded Great Fish River system, South Africa. For the native fishes, there were contrasting environmental niche breadths that varied from being small to being large and overlapped for most species, e...

The development of a residential marina estate within the Knysna estuary, South Africa, introduced Reno mattresses (horizontal wire cages filled with rocks) as a novel habitat for the endangered Knysna seahorse Hippocampus capensis. Consistently high seahorse densities on these artificial structures, despite the availability of seagrass habitat, be...

A long-term sightings and photographic identification (photo-ID) database documented the inter-annual and monthly trends in white shark (Carcharodon carcharias) sightings, sex ratios and life-history stages at Seal Island, False Bay, South Africa, over the period 2004–2012. A total of 1105 sightings were recorded during 171 scientific surveys incor...

Andreotti et al. (2016; Mar Ecol Prog Ser 552:241-253) estimate an abundance (N) of 438 white sharks Carcharodon carcharias and a contemporary effective population size (CNe) of 333 individuals along the South African coast. N was estimated by using a mark-recapture analysis of photographic identification records from a single aggregation site (Gan...

This study developed niche models for the native ranges of Oreochromis andersonii, O. mortimeri, and O. mossambicus, and assessed how much of their range is climatically suitable for the establishment of O. niloticus, and then reviewed the conservation implications for indigenous congenerics as a result of overlap with O. niloticus based on documen...

Chondrichthyans (sharks, skates, rays and chimaeras) are captured in many marine fisheries. Management and research efforts directed at chondrichthyan fishing are often neglected because of low product value, taxonomic uncertainty, low capture rates, and harvesting by multiple fisheries. In South Africa's diverse fishery sectors, which include arti...

Spotted raggedtooth sharks Carcharias taurus occur along the southern and eastern coasts of South Africa. We report on movements of juveniles and adults within a known nursery area on the Eastern Cape coast using acoustic telemetry. The focus area of the study was Algoa Bay, where six VEMCO VR2 ultrasonic receivers were placed at known shark aggreg...

Rotenone, a commonly-used piscicide, interferes with the cellular respiration of aquatic vertebrates and invertebrates by preventing the uptake of oxygen. While dose-response relationships have been developed for fish, there are limited comparative data available on aquatic insects that respire either with tracheal gills or with a plastron - a thin...

Trachinotus botla is an important recreational surf zone-dependent fish species distributed in the Indo-west Pacific from South Africa to Australia. In South Africa it is restricted to the northern KwaZulu-Natal coast. Biological investigations revealed that it is a fast growing species that attains a maximum age of ,7 years. Males and females sexu...

Pilot studies are used to assess different sampling and monitoring protocols when developing long-term monitoring programs (LTMPs). Considering that the ultimate goal of LTMPs is preservation-orientated, non-destructive sampling methods are favoured. For coral reef fishes, underwater visual censuses (UVCs) have become the method of choice for surve...

Larval fishes were studied in Shark Bay on the warm, temperate south-east coast of South Africa. The bay is a small, shallow, subtidal area associated with a rocky shore. Sampling took place fortnightly for a period of one year (September 2004–August 2005) to assess composition, abundance and growth of fishes. The objectives of the study were to as...

Animals exhibit diel periodicity in their activity in part to meet energy requirements whilst evading predation. A competing hypothesis suggests that partitioning of diel activities is less important because animals capitalise on opportunity. To test these hypotheses we examined the diel activity patterns for two cyprinid minnows, chubbyhead barb B...

Despite increasing awareness of large-scale climate-driven distribution shifts in the marine environment, no study has linked rapid ocean warming to a shift in distribution and consequent hybridization of a marine fish species. This study describes rapid warming (0.8°C/decade) in the coastal waters of the Angola-Benguela Frontal Zone over the last...

Density, population structure, growth, mortality and aspects of reproduction of the non-native amphipod Platorchestia platensis were studied for 20 consecutive months (October 2008 to May 2010) in the supralittoral wrack of the Knysna Estuary, South Africa. Amphipod density varied over the sampling period with the lowest numbers recorded in summer...

Cymothoa borbonica prevalence in the buccal cavity of Trachinotus botla was high, with 45 % of all fish sampled being infected. Smaller fish were more susceptible to infection with no parasites found in fish over 400 mm FL. The detrimental effects of parasite infection on their hosts include basihyal (the bone commonly known as the “tongue”) damage...

African sharptooth catfish Clarias gariepinus has become established as a non‐native invasive species in Eastern Cape, South Africa, where it was translocated primarily through an inter‐basin water transfer scheme into the Great Fish and Sundays rivers. This study examined the patterns in catfish distribution and abundance, and compared trophic nic...

It has been suggested that the invasive, omnivorous Clarias garipienus is capable of rapid invasions and long-term persistence in recently inhabited freshwater systems. To test this hypothesis, the life history of the established, extralimital Darlington Dam (33°10’31”S, 25°09’13”E) population was investigated. By counting post-fluorescent mark inc...

It has been suggested that the invasive, omnivorous Clarias garipienus is capable of rapid invasions and long-term persistence in recently inhabited freshwater systems. To test this hypothesis, the life history of the established, extralimital Darlington Dam (33°10’31”S, 25°09’13”E) population was investigated. By counting post-fluorescent mark inc...

We present the first quantitative study of the occurrence, size and sex of white sharks Carcharodon carcharias at Bird Island, Algoa Bay. Twenty-two boat trips were made to Bird Island between November 2009 and October 2011 to chum for sharks. A total of 53 sharks was observed over the study period, ranging in size from 1.5 to 4.5 m total length (T...

Macroinvertebrate colonisation patterns on artificial substrates were investigated in a small reservoir in the Eastern Cape, South Africa. Semi-closed 1 000 cm3 polythene netting cages filled with either brick, gravel, shredded plastic, or equal proportions of these three materials, were suspended above the benthic substrate. Gravel was preferred b...

With ocean warming predicted globally, one of the mechanisms driving distributional shifts and changes in the abundance of resident fishes is reproductive output. The relationship between sea surface temperature and the reproductive activity of a eurythermic, resident coastal species, blacktail seabream Diplodus sargus capensis, was examined in the...

The shore-fishery for Trachinotus botla in KwaZulu-Natal appears to be in a stable state. A per-recruit assessment showed that the species is currently underexploited (spawner biomass-per-recruit = 75% of pristine levels) and that fishing mortality could theoretically be increased. The fishery was shown to display considerable spatial and temporal...

1. This study outlines the development of a qualitative risk assessment method and its application as a screening tool for determining the risk of establishment and spread of the invasive Nile tilapia, Oreochromis niloticus (Linnaeus, 1758), within the central sub-catchment of the Limpopo River basin in northern South Africa. 2. The assessment used...

Information on the movement behaviour and habitat use by non‐native invasive African catfish Clarias gariepinus is crucial in understanding and possibly mitigating its potential impacts. The aim of this study was to examine catfish movement and habitat selection within an invaded impoundment in the Eastern Cape, South Africa. Acoustic telemetry dat...

The present study provides information on the existence of a possible inshore nursery area for white sharks (Carcharodon carcharias) in Algoa Bay, South Africa. In total, 43 flights were conducted, using a Robinson R22 helicopter, between October 2010 and March 2012. A total of 50 white sharks was sighted, with a maximum sighting rate of seven shar...

This study applied ecological niche mod-els to determine the potential invasive range of Nile tilapia, Oreochromis niloticus, with a particular focus on river systems in southern Africa where it is now established and spreading. Computational tools such as niche models are useful in predicting the potential range of invasive species, but there are...

This study examined temporal variation in population dynamics and size structuring of two cyprinid minnows, Pseudobarbus afer and Barbus anoplus, in relation to their proximate physical habitats. Population estimates were determined using three‐pass depletion sampling during both summer and winter. The habitats were characterised by seasonal variat...

Catches from Angling Week competitions between 1999 and 2010 were analysed to examine changes in catch and effort. Over the course of the study period there was a marked drop in the number of competing anglers and a significant reduction in the total number of fish caught (p = 0.026). There was also a significant (p < 0.01) shift in the areas fishe...

In aquatic ecosystems, impacts by invasive introduced fish can be likened to press disturbances that persistently influence communities. This study examined invasion disturbances by determining the relationship between non-native sharptooth catfish Clarias gariepinus and aquatic macroinvertebrates in the Eastern Cape, South Africa. A Multiple Befor...

The life history of an endemic riverine African cyprinid, Labeo capensis, that dominates the larger ichthyofauna in a large impoundment in the Orange River Basin four decades after damming, was investigated. Both sexes grew at a similar rate until the onset of maturation, after which male growth and survival rates declined. Male mortality rate was...

Despite coelacanths, Latimeria chalumnae, being listed as either endangered by CITES or critically endangered by the IUCN, their population size within South Africa is unknown and still needs to be estimated. Their conservation status unfortunately excludes the use of conventional tagging to mark individual animals for a possible mark–recapture exp...

The life history of an endemic riverine African cyprinid, Labeo capensis, that dominates the larger ichthyofauna in a large impoundment in the Orange River Basin four decades after damming, was investigated. Both sexes grew at a similar rate until the onset of maturation, after which male growth and survival rates declined. Male mortality rate was...

Releasing aquarium-held sharks when no longer needed by the holding institution may help mitigate the impacts that aquaria have on declining wild populations. To investigate the viability of releasing display specimens, four raggedtooth sharks (Carcharias taurus) that had been held at Two Oceans Aquarium, Cape Town were released back to the wild be...

The effects of marine reserves on the growth and mortality rates of 2 commonly exploited (Helcion concolor and Scutellastra longicosta) and 2 rarely exploited (Cellana capensis and Scutellastra granularis) limpets were investigated at 2 reserve and 2 non-reserve sites in South Africa. Two hypotheses were tested: (1) growth of commonly exploited spe...

The stable isotope ratio and seasonal changes in diet of two indigenous (Oreochromis mossambicus, Tilapia rendalli) and one exotic (Oreochromis niloticus) tilapiine cichlids in the subtropical Limpopo River, South Africa were investigated to determine patterns of resource partitioning. Stomach contents of O. niloticus and O. mossambicus indicated h...

Intramuscular injection of the antibiotic Oxytetracycline (OTC) has been the only method previously employed for chemically marking C. gariepinus otoliths for ageing studies. This study compared intramuscular injection, immersion, and dietary incorporation methods of administering OTC to determine the most effective technique. No differences in eit...

Sharptooth catfish Clarias gariepinus was introduced into the Eastern Cape Province, South Africa, in 1976 and there are concerns about its possible negative impacts on native biota. This study investigated its trophic impact by examining its feeding habits. Stomach content and stable isotope analyses were compared from three localities—the Great F...

Intramuscular injection of the antibiotic Oxytetracycline (OTC) has been the only method previously employed for chemically marking C. gariepinus otoliths for ageing studies. This study compared intramuscular injection, immersion, and dietary incorporation methods of administering OTC to determine the most effective technique. No differences in eit...

As one of the most widely established freshwater fishes globally, the invasive success of common carp, Cyprinus carpio, is beyond dispute. Although detailed knowledge on its biology would assist in its management, relatively few life history studies have investigated C. carpio outside of its natural range. The present study analyses the life histor...

This study documents validation of vertebral band-pair formation in spotted gully shark (Triakis megalopterus) with the use of f luorochrome injection and tagging of captive and wild sharks over a 21-year period. Growth and mortality rates of T. megalopterus were also estimated and a demographic analysis of the species was conducted. Of the 23 OTC...

African sharptooth catfish, Clarias gariepinus, is a successful aquatic invader as it has a eurytopic physiology, is highly fecund, grows quickly and has an omnivorous diet. Despite possible threats that include predation of and competition with indigenous species, habitat degradation, and the spread of diseases and parasites, there is a lack of kn...

A total of 816 common carp Cyprinus carpio asteriscus otolith pairs were collected from Lake Gariep, South Africa. Otoliths were interpreted whole, submerged in methyl salicylate and viewed under transmitted light. The precision of growth zone counts of the primary reader was estimated at 5·54 and 7·03% using the average per cent error method and t...

African sharptooth catfish, Clarias gariepinus, is a successful aquatic invader as it has a eurytopic physiology, is highly fecund, grows quickly and has an omnivorous diet. Despite possible threats that include predation of and competition with indigenous species, habitat degradation, and the spread of diseases and parasites, there is a lack of kn...

A geographic information systems (GIS) based atlas of southern African freshwater fish has been developed for the SADC countries. The JLB Smith Institute of Ichthyology, in collaboration with ALCOM, has developed a database of freshwater fish for this region from museum collection data. The development of advanced computing and GIS technology has i...

The effect of temperature (15 and 25°C) and salinity (15 and 35 practical salinity units) combinations on the growth and longevity of the South African estuarine isopod Exosphaeroma hylocoetes was investigated and data analysed using the logistic growth model. No significant differences (P = 0.43 to 0.54) were obtained for the growth rates of male...

Changes in the Eastern Cape demersal inshore trawl fishery operating out of Port Elizabeth over a 28-year period from 1967 to 1995 are described. The fishery is restricted to vessels operating between Slangbaai in the west to Port Alfred in the east. The principal target species are the shallow-water Cape hake and Cape horse mackerel. Eight of the...

We tested the hypothesis that growth zones in the astericus otoliths of smallmouth yellowfish (Labeobarbus aeneus) and Orange River mudfish (Labeo capensis) were deposited annually. Two methods, fluorochrome marking and edge analysis of otoliths were used. For fluorochrome marking, specimens of both species were injected with 60 mg/kg fish mass oxy...

We tested the hypothesis that growth zones in the astericus otoliths of smallmouth yellowfish (Labeo-barbus aeneus) and Orange River mudfish (Labeo capensis) were deposited annually. Two methods, fluorochrome marking and edge analysis of otoliths were used. For fluorochrome marking, specimens of both species were injected with 60 mg/kg fish mass ox...

The effect of temperature (15 and 25°C) and salinity (15 and 35 practical salinity units) combinations on the growth and longevity of the South African estuarine isopod Exosphaeroma hylocoetes was investigated and data analysed using the logistic growth model. No significant differences (P = 0.43 to 0.54) were obtained for the growth rates of male...

South African inland fisheries are poorly developed and their contribution to near-shore communities is poorly understood. This study is the first comprehensive assessment of recreational and subsistence angling undertaken in an inland fishery in South Africa. The study was conducted on the 360 km2 Lake Gariep, South Africa's largest freshwater res...

Six indicators were investigated for South African sardine Sardinops sagax and anchovy Engraulis encrasicolus: mean length of catch, length-at-50% maturity, total mortality, exploitation rate, ratio of bycatch, and centre of gravity of commercial catches. Sardine length-at-50% maturity is the most promising as a descriptive indicator because it is...

The reproductive and recruitment characteristics of moggel, Labeo umbratus, populations were examined in four small South African reservoirs. Reproduction, characterised by an extended spawning season, high fecundity, short incubation time and rapid larval development, appears to be ideally suited to the highly variable environment of small reservo...

The ovaries of Labeo victorianus are paired organs situated in the peritoneal cavity and suspended on either side of the midline by a mesovarium. A capsule, composed of dense, regularly-arranged collagen and elastic fibres mixed with a few smooth muscle cells, enclosed the ovaries and gave off connective tissue septa, forming the ovigerous lamellae...

Diplotaxodon limnothrissa is a widely distributed species occurring throughout Lake Malawi and is probably the most abundant cichlid in the pelagic zone of the lake. The species is exploited commercially in the south-east arm of the lake, but since the fishery's inception the resource has never been assessed. Per-recruit analysis indicated that the...

South African inland fisheries are poorly developed and their contribution to near-shore communities is poorly understood. This study is the first comprehensive assessment of recreational and subsistence angling undertaken in an inland fishery in South Africa. The study was conducted on the 360 km2 Lake Gariep, South Africa’s largest freshwater res...

Understanding differences in the recapture rate between different tags (A-, B- and C-types), capture methods (rock-and-surf anglers, scientific divers and Natal Sharks Board protection nets) and life-history stages (juvenile and adult) is critical in evaluating the results obtained from cooperative tagging programmes (CTPs). A generalised linear mo...

The age, growth and reproductive biology of Marcusenius pongolensis, Oreochromis mossambicus and Schilbe intermedius were investigated in the Mnjoli Dam, Swaziland. Otolith annulus formation occurred in winter for M. pongolensis, and in spring/summer for O. mossambicus and S. intermedius. Maximum ages of 8, 6 and 8 years were recorded for M. pongol...

Rapid biological assessments have been proposed as the most cost-effective approach to identify suitable target species and to set initial catch and fishing effort levels for new fisheries. Xonxa Dam, a turbid irrigation dam situated in the White Kei catchment, rural Eastern Cape, is shown to provide fisheries potential for two alien species — smal...

Abstract The home range and area use of spotted grunter, Pomadasys commersonnii (Haemulidae) (Lacepède), were investigated in the Great Fish estuary, South Africa. Forty individuals (263–698 mm TL) were surgically implanted with acoustic-coded transmitters and manually tracked during two periods in 2003. Tagged fish spent on average 68 and 77% of t...

The deposition rate of growth zones in sagittal otoliths of wild Clarias gariepinus that were fluorochrome marked with oxytetracycline and recaptured after a period of between 0·44 and 2·13 years was consistent with the deposition of one growth increment annually.

A double-tagging experiment is presented that estimates tag retention by plastic dart and T-bar anchor tags in a wild population of Clarias gariepinus. It is shown that plastic dart tags are the most suitable tag as there was 100% initial retention and long-term loss of 2% per annum. T-bar anchor tags had an initial tag retention rate of 81% and no...

Gonadal differentiation was histologically investigated in juvenile Labeo victorianus from Lake Victoria. Sex differentiation was marked by division of gonocytes and formation of an ovary-like structure with previtellogenic oocytes. Definitive sex differentiation was by either continued oogenesis, or by atresia of the previtellogenic oocytes with c...

Telemetry methods were used to investigate the influence of selected environmental variables on the position and movement of an estuarine-dependent haemulid, the spotted grunter Pomadasys commersonnii (Lacepède 1801), in the Great Fish Estuary, South Africa. Forty individuals (263–698 mm TL) were surgically implanted with acoustic coded transmitter...

Factors influencing estuarine use and marine excursions by spotted grunter Pomadasys commersonnii in the Great Fish Estuary, South Africa, were studied using manual and automated telemetry methods. In all, 20 individuals, ranging from 362 mm to 698 mm total length (TL), were caught and tagged with acoustic-coded transmitters in the estuary. Tagged...

Grandcourt, E. M., Hecht, T., Booth, A. J., and Robinson, J. 2008. Retrospective stock assessment of the Emperor red snapper (Lutjanus sebae) on the Seychelles Bank between 1977 and 2006. – ICES Journal of Marine Science, 65: 889–898. The stock status of the Emperor red snapper (Lutjanus sebae) on the Seychelles Bank was determined between 1977 and...

A Cormack-Jolly-Seber model was developed to estimate abundance, survival, and probability of capture for juvenile (<1.8 m total length, TL) and adult (>1.8 m TL) raggedtooth sharks (Carcharias taurus) along the east coast of South Africa. Model estimates were adjusted to account for tag loss, nonreporting, and after release mortality. The model wa...

Polydorid polychaetes can infest cultured abalone thereby reducing productivity. In order to effectively control these pests, their reproductive biology must be understood. The population dynamics and reproduction of polydorids infesting abalone Haliotis midae from two farms in South Africa is described using a length-based, age-structured model. S...

Although migration patterns for various life history stages of the chokka squid (Loligo reynaudii) have been previously presented, there has been limited comparison of spatial variation in biological parameters. Based on data from research surveys; size ranges of juveniles, subadults and adults on the Agulhas Bank were estimated and presented spati...

Two spawning inducing agents—Aquaspawn (a rapidly metabolized synthetic decapeptide gonadotropin-releasing hormone [GnRH]) and Dagin ([D-Arg6, Pro9-NEt]-sGnRH) combined with 20 mg/kg of the water-soluble dopamine receptor antagonist metoclopramide (GnRH + MET)—were tested for their efficacy in stimulating ovulation in Labeo victorianus held in its...

Understanding the movement patterns of raggedtooth sharks (Carcharias taurus) is crucial in defining habitat use and evaluating the effects of exploitation and anthropogenic activities. Between 1984 and 2004, 1107 C. taurus juveniles (<1.8-m TL) and 2369 C. taurus maturing subadults and adults (>1.8-m TL) were tagged and released along the east coa...