Zoogeography of the coral reef fishes of the Socotra Archipelago

Fish communities and habitats were studied at the Socotra archipelago (Gulf of Aden, ≈12°N 54°E). Extensive and unexpected hermatypic coral communities were recorded, at the centre of a 2200 km gap in knowledge of species and habitat distributions which coincides with a change from a western Indian Ocean coral reef fauna to an Arabian one. The fish assemblage associated with the Socotra archipelago corals is predominantly south Arabian. An east African influence, minimal on the mainland coasts of Arabia, is more evident here, and results in previously unrecorded sympatry between Arabian endemic species and their Indian Ocean sister taxa. A study of distributions of Chaetodontidae (butterflyfishes) in the north-western Indian Ocean reveals a number of distinct patterns, with a trend for species replacement along a track from the northern Red Sea to the Indian Ocean. A major feature of the reef fish zoogeography of the region is found to be a distinct south Arabian area, characterized by a 'pseudo-high latitude effect' which results from seasonal cold water upwelling along the Arabian sea coasts of Yemen and Oman and the Indian Ocean coast of Somalia. This south Arabian feature is consistent across a wide range of fish families. It is most pronounced in Oman and Yemen, and although it is the dominant influence at Socotra it is slightly 'diluted' here by the east African influence. The south Arabian area wholly or partly accounts for most of the major marine zoogeographic features around Arabia, and is the principal feature fragmenting Arabian coastal fish assemblages, and separating them from those of the wider Indo-west Pacific.     

Distribution and taxonomy of shallow marine Ostracods from Northern Socotra Island (Indian Ocean) - Yemen

Forty-seven species belonging to 30 genera of ostracods have been identified from Recent shallow marine sediments collected along the northern coastline of the island of Socotra (Indian Ocean). The systematics and distribution of these ostracods are discussed. Three genera, Loxoconcha, Bosasella, and Xestoleberis are found to have high species diversity. The species Loxoconcha ghardaqensis, Moosella striata are best documented in the Red Sea and Gulf of Aden while Kotoracythere inconspicua and Triebelina sertata were found to be the most widespread species. The fauna shows a close affinity to other ostracod assemblages of the Indo-Pacific region, East African coast and Red Sea.     

Aquatic entomofauna of a Dead Sea oasis

A survey of the aquatic and semi-aquatic insect fauna of a semi-tropical, arid zone oasis on the western Dead Sea coast, was conducted primarily in the summer and winter seasons of 1980/81. A table is given of the aquatic entomofauna, including their zoogeographical affinities, Israeli distribution and presence in En Gedi and in each of the two canyons there. Zoogeographical analysis reveals a predominance of tropical and arid African affinity (Ethiopian = 31%, Saharo-Arabian = 19%), with a major affinity also to the Mediterranean (21%). The entomofaunal community was divided among seven ecological biotopes: fast or slow flowing streams and pools; eddies; bedrock or deep pools; standing or stagnant pools. A community analysis table of the occurrence of the major faunal elements in each of seven biotopes is presented. Some rather stenotopic taxa were indicative of biotopes. A comparison is made of summer and winter seasonality including the effects of flash floods and the relation of these phenomena to emigration/imigration and life cycles of the entomofauna. The effects of agriculture and tourism are discussed and proposals made for conservation of the biotope communities. These biotopes and their entomofaunal communities are presumed to represent most of the habitats of Middle East arid zone springs.     

A new species of the wild dragon tree, Dracaena (Dracaenaceae) from Gran Canaria and its taxonomic and biogeographic implications

The arborescent taxa of Dracaena which form the dragon tree group comprise five species found in Macaronesia, Morocco (D. draco), East Africa (D. ombet, D. schizantha), Arabia (D. serrulata) and the island of Socotra (D. cinnabari). A new species of dragon tree, Dracaena tamaranae A. Marrero, R. S. Almeida & M. Gonzalez-Martin, is described from Gran Canaria, Canary Islands. This new species differs from D. draco, the only other Dracaena species currently known in Macaronesia, in having a growth form and inflorescence type and leaves more similar to the East African and Arabian species of Dracaena. In contrast, D. draco appears to be related to D. cinnabari. In this paper, we also present a study of the taxonomy, habitat and ecology of all the species of the dragon tree group. These are found in thermo-sclerophyllous plant communities of tropical-subtropical regions which are rather xerophilous and have a rainfall range of 200–500 mm. Our study indicates two independent colonization events for Dracaena in Macaronesia. In addition, we suggest that the dragon tree group provides an example of two major biogeographical disjunctions between East and West Africa. We postulate that this group has a Tethyan origin, a hypothesis supported by fossil and palaeoclimatic data, and thus parallels the distribution and dispersal pattern of other taxonomic groups.     

Biotopes and spatial organization of arthropod communities

Plant, spider, beetle, and ground beetle communities were studied in different agrolandscape biotopes (a wheat field, a field margin, and a forest belt) of Krasnodar Territory. In these biotopes, borders between plant communities were distinct. On the contrary, arthropod communities were not usually confined to the certain biotopes. The high degree of mobility of arthropod species resulted in a decrease in their association with the biotope. Representatives of some species (especially, beetles) were revealed in all the biotopes. In relation to season and some other factors, they frequently concentrated in different biotopes. Analysis of arthropod assemblages only within a single biotope gives us a rather impoverished knowledge of the whole population. It is necessary to study these assemblages not only within the basic biotope, but also in adjacent ones.     

Movement and habitat use of striped marlin Kajikia audax in the Western Indian Ocean

Striped marlin Kajikia audax are globally Near Threatened and their stock in the Indian Ocean was last assessed as “overfished and subject to overfishing”. Significant gaps in our understanding of their ecology remain, hampering the efforts of fisheries managers to ensure stock sustainability. There is a particular lack of fisheries-independent data. Here we present the results from the first large-scale satellite tracking study of K. audax in the Indian Ocean. We tagged 49 K. audax with pop-up archival satellite-linked tags off the Kenyan coast from 2015 to 2019. Individuals were highly mobile, covering horizontal distances of up to 9187 km over periods ranging up to 183 days, with a mean daily distance of ~48 km. Long-distance movements were recorded to the east and north of East Africa, with the most distant tracks extending north to the Arabian Sea and east to near the Maldives. None of the K. audax swam south of East Africa. Kernel utilization distributions of fish locations demonstrated their shifting seasonal activity hotspots. Over the sport-fishing season (and tagging period) in Kenya, from December to March, K. audax typically stayed off the East African coast. After March, the activity hotspot shifted north to a region close to the Horn of Africa and Socotra Island. Remotely sensed sea surface temperature and chlorophyll-a maps indicated that this seasonal movement could be driven by a shift in prey availability. Our results show the high mobility of K. audax in the Western Indian Ocean, and that individuals seasonally range between two major fishing areas.     

THE SEA-BIRDS OF THE SOUTHEAST COAST OF ARABIA

The present study of an upwelling area off the southeast coast of Arabia, between 52° and 60° E. is based primarily on observations on board the R.R.S, `Discovery’ during the International Indian Ocean Expedition. During oceanographic surveys off the Arabian coast from June to August 1963 and in early March and late May 1964 I made 234 counts of birds of about an hour each, the results of which have been used as an index of bird density. In this area, the only offshore islands known to be important to sea-birds are the Kuria Muria Islands, which were apparently at the centre of an upwelling area. The upwelling of cold water along the Arabian coast during the southwest monsoon from May to September greatly increases organic production in the sea, and large populations of organisms at every level of the food chain develop there. Previous work in Arabia and the Arabian Sea is reviewed. Little is recorded about the ecology of sea-birds there, but the composition of the fauna is quite well-known. The distribution of every sea-bird species recorded from 52° E. to 60° E., and within 200 miles offshore, is described, with particular reference to my own observations. Details are given of the distribution of common species during the southwest monsoon of mid-June-mid-August 1963 and in March and May 1964. Specimens collected on the `Discovery’ are recorded together with their measurements. Of 12 sea-bird species seen commonly off Arabia during the southwest monsoon in 1963, 11 were seen in late May 1964, but only five in March. There is certain evidence that two species have bred on the Kuria Muria Islands and suggestive evidence for a further three. Information on breeding seasons in the Arabian Sea is based on short visits to breeding colonies, mostly outside the breeding season, and on the plumage condition of specimens. Nevertheless, the sum of the evidence suggests that breeding is regular at the same time every year, and in most species seems to be in the northern summer. The food of sea-birds in the Arabian Sea, determined from stomach contents and visual observation, only serves to stress the lack of knowledge on this subject. A brief summary of feeding methods recorded by me suggests that they may be important in avoiding interspecific competition, for there seems to be little overlap. The density of sea-birds during the southwest monsoon 1963, expressed as the number of each species seen per hour, was analysed in relation to: (i) the sea surface temperature, which was inversely correlated with the zooplankton density from 0–200 m. (ii) the distance from the Kuria Muria Islands, the only likely breeding station; (iii) the distance from the nearest land which may have been important to land-tied sea-birds. All the abundant species were commonest close to land in the cool-water area and, with the exception of migrants from the southern hemisphere, most were concentrated around the Kuria Muria Islands in the centre of upwelling. A multiple analysis suggested that the islands were of real importance to some species. A separate analysis also demonstrated the existence of a correlation between sea-bird numbers and the abundance of zooplankton from 0–200 m. depth, but not the abundance of zooplankton at the sea surface. During the southwest monsoon the southeast Arabian coast is inhabited by a distinctive cool-water fauna within the tropical zone of the Indian Ocean. The high degree of endemism, the high proportion of migrants, including some from the southern hemisphere, and the absence of most pantropical species, suggest that the marked changes in the environment off southeast Arabia demand considerable adaptation. A brief discussion of the possible origins of the Arabian coast sea-bird fauna shows that it is not typical of either a subtropical or a tropical community in other regions. The likelihood that sea-birds breed in the summer, the concentration of most species in the upwelling area at that time and their absence during the winter, clearly demonstrates the importance of the upwelling. However, the results of the analysis suggest that some species were concentrated around the Kuria Muria Islands in the centre of the upwelling because the islands had a real importance to them, possibly as a breeding station. The correlation between sea-bird density and zooplankton abundance in the top 200 m., but not at the surface, may be explained if sea-birds concentrate in areas of high productivity rather than in areas of abundant surface plankton, which is largely irrelevant as food.     

Testate amoebae communities in the southern tundra and forest-tundra of Western Siberia

The species composition and community structure of soil-inhabiting testate amoebae communities have been studied in biotopes of different types in the southern tundra and forest-tundra of the Tazovskaya Lowland, Western Siberia. A total of 93 species and forms have been identified. It has been found that the species richness of testate amoebae is much lower in dry than in moist biotopes due to a lower level of beta-diversity, with alpha diversity being the same (on average, 16.9 and 17.1 species per sample, respectively). Factors acting at the microbiotope level (biotope type and moisture) play the most important role in the formation of species richness; biotope features (soils and vegetation) are second in importance. In moist habitats, local communities of testate amoebae from different microbiotopes (mosses, lichens, or litter) are fairly similar in species structure, and communities from different moist biotopes are heterogeneous. In dry areas, the opposite situation is observed: local communities differ at the microbiotope level but are similar at the biotope level. The abundance of testate amoebae in moist biotopes reaches 200 × 10³ ind./g dry soil, being an order of magnitude lower in dry biotopes.     

Characteristics of plant communities containing St. John’s wort (<Emphasis Type="Italic">Hypericum perforatum</Emphasis> L.) in the Saratov Region

Analysis of 28 plant communities containing Hypericum perforatum L. in five different biotope types has been performed in 17 districts of the Saratov Region. A total of 325 species from 197 genera of 52 vascular plant species have been recorded, with plants characteristic of forest-edge, steppe, and anthropogenic biotopes prevailing in most communities. It has been shown that H. perforatum at the southeastern boundary of its range behaves as an explerent species. The main factor limiting its growth in biotopes of a certain type is the degree of disturbance in the structure of corresponding communities rather than by their taxonomic composition.     

Zoogeography of the shallow-water holothuroids of the western Indian Ocean

Aim To analyse the zoogeography of the shallow‐water holothuroids of the western Indian Ocean (WIO). Based on this analysis we ask to what extent differences in species’ ability to disperse across potential barriers provide an explanation for holothuroid zoogeography. Location Shallow‐waters (50 m isobaths) of the WIO, extending from Suez to Cape Town and from the coastline of East Africa upward to 65° E. Methods Data for the analysis were obtained from Samyn's (2003) monograph on the shallow‐water sea cucumbers of the WIO. A species presence/absence matrix with a resolution of 1° latitude/longitude was constructed. These cells were assigned to eight coarser operational geographical units, which were delimited on the basis of published faunistic and geological borders. The analytical zoogeographical methods employed were cluster analysis on several β‐diversity coefficients and parsimony analyses of endemicity. The influence of life‐history strategies on the distribution pattern was analysed through examination of latitudinal and longitudinal gradients, and by plotting cumulative curves for species number against range size. Results The shallow‐water holothuroid fauna of the WIO can be split into several biogeographical units. To the north, we found evidence that the northern Red Sea holothuroid fauna differs from that of the southern Red Sea. The latter has closest affinity with south‐east Arabia and the Persian Gulf, and thus the biogeographical barrier of Bab‐el‐Mandab nowadays seems to be of minor importance. The cold upwelling at the east coast of Somalia forms an effective barrier for holothuroids and especially those with lecitothrophic (short‐lived) larvae. Even though the circumtropical biogeographical pattern is not well resolved, important taxonomic turnovers suggest that it is composed of several distinct subprovinces. Taxonomic turnover is at least partially dictated by the dispersion capacity of the different orders. Main conclusions This study concludes that the WIO is best split into at least three biogeographical realms: (1) the Red Sea and associated Arab Basin, (2) the asymmetrical circumtropical region stretching from the horn of Africa to southern Mozambique, and (3) southern Africa. Conspicuous differences in dispersal abilities of the three dominant orders are identified. The biogeography of the WIO is best explained by: (1) species’ dispersion ability, (2) the prevalent current patterns, and (3) to a lesser, geographically limited extent, recent geological history. As a serendipitous discovery, we found that Rapoport's rule does not hold in the WIO.     

TEMPERATURE THRESHOLD AS A BIOGEOGRAPHIC BARRIER IN NORTHERN INDIAN OCEAN MACROALGAE1

The most eastern point of the Arabian Peninsula, Ras Al Hadd, marks the boundary between the Arabian Sea and the Gulf of Oman. This geographic landmark coincides with an abrupt floristic turnover, probably one of the sharpest biotic transitions known in marine biogeography. The floras of different Arabian localities across this floristic break were compared using macrophyte distribution data throughout the Indian Ocean and seasonal sea‐surface temperature (SST) data. The localities from the Arabian Gulf and Gulf of Oman differ significantly from those of the Arabian Sea based on their species richness, species composition, average distribution range per species, general temperature affinity of the composing species, and seasonal temperature data of the coastal waters. Pooling the temperature data into two groups (SST_3avg, average SST of the three warmest seasons; SST_min, minimum of the seasonal SSTs) revealed a temperature limit at 28°C using both the temperature affinity data of the floras and the seasonal temperatures recorded for the specific Arabian localities, which significantly separates the Arabian Sea from localities of both Gulfs. Finally, SST data of the Indian Ocean were analyzed using this upper temperature threshold of macrophytes at 28°C and the lower temperature limit of corals at 25°C, revealing general macrophyte diversity patterns.     

Community structure and biogeography of shore fishes in the Gulf of Aqaba,Red Sea

Shore fish community structure off the Jordanian Red Sea coast was determined on fringing coral reefs and in a seagrass-dominated bay at 6 m and 12 m depths. A total of 198 fish species belonging to 121 genera and 43 families was recorded. Labridae and Pomacentridae dominated the ichthyofauna in terms of species richness and Pomacentridae were most abundant. Neither diversity nor species richness was correlated to depth. The abundance of fishes was higher at the deep reef slope, due to schooling planktivorous fishes. At 12 m depth abundance of fishes at the seagrass-dominated site was higher than on the coral reefs. Multivariate analysis demonstrated a strong influence on the fish assemblages by depth and benthic habitat. Fish species richness was positively correlated with hard substrate cover and habitat diversity. Abundance of corallivores was positively linked with live hard coral cover. The assemblages of fishes were different on the shallow reef slope, deep reef slope and seagrass meadows. An analysis of the fish fauna showed that the Gulf of Aqaba harbours a higher species richness than previously reported. The comparison with fish communities on other reefs around the Arabian Peninsula and Indian Ocean supported the recognition of an Arabian subprovince within the Indian Ocean. The affinity of the Arabian Gulf ichthyofauna to the Red Sea is not clear. Received in revised form: 2 November 2001 Electronic Publication     

Halacaridae (Acari) von der Atlantikküste des borealen Nordamerikas

38 halacarid species from the coasts of the boreal West Atlantic Ocean have been recorded. In a wide-spread net of stations, samples were taken from different substrata in marine and brackish waters in order to obtain information on the biology and ecology of halacarid species. Several habitats with their flora, fauna and halacarid species are described. In intertidal areas on the coasts of boreal North America fewer species were found than known from European coasts. Similar habitats on the west and east coasts of the North Atlantic Ocean are compared with respect to their halacarid population. In the rhombognathine and the genusHalacarellus, most species found in the West Atlantic Ocean are known in the East Atlantic too, living in similar habitats. The generaAnomalohalacarus andCopidognathus are common both in North American and European waters, but comparable biotopes are inhabited by different species, though often related or very similar in their appearance. 45 % of the halacarid species found in the boreal West Atlantic Ocean are also known in the East Atlantic. Hypotheses as to the dispersal and geographical distribution of halacarid genera and species are discussed. It is supposed, that many of the amphiatlantic species invaded biotopes on the American and European coasts, shortly after these continental plates drifted apart.     

Variability in abundance and fluxes of dimethyl sulphide in the Indian Ocean

Dimethyl sulphide (DMS) is a biogenic gas of climatic significance on which limited information is available from the Indian Ocean. To fill this gap, we collected data on DMS and total dimethylsulphoniopropionate (DMSP_t) by participating in a dozen cruises. Here, we discuss the variability in DMS and DMSP_t in the north and central Indian Ocean in terms of their spatial and temporal variation. DMS and DMSP_t exhibited significant spatial and temporal variability. Apart from the concentration gradients in DMS within the Arabian Sea, Bay of Bengal and Central Indian Ocean basins, differences in average abundances were conspicuous between these basins. The Arabian Sea contained more DMS (mixed layer average was 7.8 nM) followed by the Bay of Bengal (2.8 nM) and the Central Indian Ocean (2.7 nM). The highest concentrations of DMS and DMSP_t (525 nM and 916 nM, respectively) were found in upwelling regimes along the west coast of India during the Southwest monsoon and fall intermonsoon seasons. Average surface DMS was the highest in the Arabian Sea. On the other hand observed sea-to-air fluxes of DMS were higher in the Bay of Bengal due to the prevalence of turbulent conditions. In the Arabian Sea wind speeds were low and hence the sea-to-air fluxes. The total diffusive flux of DMS from the study area to atmosphere is estimated to be about 1.02 × 10¹² g S y⁻¹, which contributes to 4.1–6.3% of the global DMS emission     

Floristical and ecological characterization of the polar desert zone of Greenland

Abstract. Species composition and biomass of four plant communities were investigated in two coastal polar desert areas in eastern North Greenland, bordering the North East Water Polynya - an ice-free sea area kept open by upwelling - and compared with inland areas in North Greenland. Herb barren, the poorest type, has a species richness of 6 species/m², a cover of 0.7 %, and an aboveground biomass of 0.6 g/m² (vascular plants). The richest type, Saxifraga oppositifolia snowbed, has 10 species/m², 5.0 % cover, and 11.2 g/m² biomass. A floristic and vegetation boundary exists a few kilometres from the coast. The coastal areas bordering the North East Water Polynya had an impoverished flora and vegetation compared to areas near the ice-covered sea, possibly caused by very low summer temperatures and high frequency of clouds. A new delimitation of the polar deserts of Greenland is proposed on the basis of the number of vascular plant species, the occurrence of species with a specific inland distribution in North Greenland and the dominating life forms. At present the polar desert zone includes only areas within a zone up to ca. 15 km from the outer coast of high arctic Greenland - north of ca. 80° N. Large areas formerly classified as polar deserts in eastern North Greenland, as well as in Washington Land in western North Greenland, are excluded. New floristic data confirm that Greenland is correctly included in the Canadian province of the arctic polar deserts, whereas there is no reason for subdividing the polar deserts of the Canadian province.     

A reappraisal of the systematic affinities of Socotran,Arabian and East African scops owls (Otus,Strigidae) using a combination of molecular,biometric and acoustic data

We investigated phylogenetic relationships among Otus scops owls from Socotra Island, the Arabian Peninsula and East Africa using molecular, vocalization and biometric data. The Socotra Scops Owl Otus senegalensis socotranus, currently treated as a subspecies of the African Scops Owl Otus senegalensis, is more closely related to the Oriental Scops Owl Otus sunia and to the endemic Seychelles Scops Owl Otus insularis. Considerable mitochondrial genetic distance and significant morphological differentiation from its two closest relatives, as well as its distinctive vocalizations compared with O. insularis, strongly support recognition of Socotra Scops Owl as a full species. Unexpectedly, two taxa from the Arabian Peninsula, Pallid Scops Owl Otus brucei and African Scops Owl Otus senegalensis pamelae, represent very distinct lineages; O. brucei is basal to a clade that includes taxa found in the Indo‐Malayan region and on Indian Ocean islands. In contrast, O. s. pamelae occupies a well‐supported basal position within a clade of continental Afro‐Palaearctic taxa. The uncorrected‐p genetic distance between O. s. pamelae and its closest relatives (other populations of senegalensis from mainland Africa) is c. 4%. As O. s. pamelae is also well differentiated phylogenetically, morphologically and vocally from O. s. senegalensis, we recommend its elevation to species status, as Otus pamelae. Among mainland African O. senegalensis subspecies, Ethiopian populations appear to represent the most divergent lineage, whereas other lineages from Somalia, Kenya and South Africa are poorly differentiated. The large genetic distance between the Ethiopian haplotype and other African haplotypes (3.2%) suggests that the Ethiopian Otus may represent a cryptic taxon, and we recommend that more individuals be sampled to assess the taxonomic status of this population.     

Biogeographical patterns in endoparasite communities of a marine fish (Sebastes capensis Gmelin) with extended range in the Southern Hemisphere

Aim The endoparasites of Sebastes capensis Gmelin are examined over most of its geographical range (coasts of Peru, Chile, Argentina and South Africa) to determine: (1) whether the endoparasite communities of this fish show zoogeographical patterns; and (2) if so, whether there are any relationships between spatial variations in the endoparasite fauna and known zoogeographical patterns for marine free‐living organisms (e.g. prey that are included in the life cycles of endoparasites). Location Fish were captured at nine localities along the Pacific coast of South America, from 11° S in the centre of the Peruvian coast, to 52° S in southern Chile, and also at two localities in the Atlantic Ocean, at 43° S in Argentina, and 34° S in South Africa. Methods From April to September 2003 and April to August 2004, 626 fish were captured. Endoparasites and diet were examined following traditional methods. Cluster analyses were used to evaluate the distribution patterns of the endoparasite communities, and to evaluate similarities in the prey composition per locality. Results The endoparasite fauna of S. capensis consisted of four species widely distributed along the Pacific coast: Ascarophis cf. sebastodis, Anisakis sp., Corynosoma australe, and Pseudopecoelus sp. Other parasites were distributed only in some geographical areas. The species richness of the parasite communities increased with latitude along the Pacific coast, while parasite communities from Argentina and South Africa showed low species richness. Cluster analyses based on endoparasite composition and on prey composition grouped localities in a way consistent with known biogeographical areas for marine free‐living organisms. Main conclusions The endoparasites of S. capensis exhibit a pattern associated with known biogeographical areas for free‐living organisms. The latitudinal increase in endoparasite community richness is associated with changes in prey composition (intermediate hosts) and also possibly with the presence of definitive hosts. Therefore, the biogeographical patterns of prey are considered key determinants of the endoparasite community structure of the host.     

Bioaccumulation of lithium by marine organisms in European, American, and Asian coastal zones: microanalytic study using secondary ion emission

37 species of aquatic mammals, fish, crustacea, annelids, molluscs belonging to cephalopods, gasteropods and lamellibranchs were collected from coastal waters of France: North Sea, English Channel, Atlantic Ocean, Mediterranean Sea, from Greece: Aegian Sea, from North America: Atlantic Ocean and from Japan: Pacific Ocean, Sea of Japan and East China Sea. Microanalyses which were performed on organs and tissues, using secondary ion mass spectrometry, revealed high concentrations of lithium, which is commonly used in human therapy, but is also toxic in low amounts. The retention of this metal by the marine organisms appears as a general phenomenon independent of their biotope and geographical origin; the highest lithium levels were detected in the fish muscles (= edible part).