Scientific research topics 1998

1.) GROWTH OF HERMATYPIC CORALS II: RELOCATION OF MARKED COLONIES AND FIRST RESULTS
Leopold Feichtinger, Bernhard Kaar, Örjan Klappert, Tom Puchner

Abstract
This contribution presents the first results on the annual growth of reef-building corals in the Gulf of Aqaba. The project was initiated in November 1997 and first results were received in November 1998. The best results could be seen with branching colonies as Acropora sp., Stylophora pistillata, and Pocillopora damicornis. But also massive corals like Favia sp., Leptoseris sp., Astreopora myriophthalma showed distinct growth. Procedures were similar to last year and are described under "Method and Materials" later on.
A new aspect was taken into account, "Growth and colonization of corals on artificial substrate". Therefore first results are to be expected in November 1999. As some problems showed up during relocating and measuring. Improvements were made and are given in the following chapters. In order to make it easier to relocate sites and find the specific colonies quickly divemaps and sketches of the new sites were made.

2.) INVERTEBRATE STRUCTURES AS HABITATS FOR POMACENTRID REEF FISHES
Grollitsch Karin, Ruffingshofer Alice, Walcher Eva

Abstract
Especially branched coral colonies are an important resource as an habitat for both, juvenile and adult reef fish. An examination in the Gulf of Aqaba, Red Sea, shows the association of three specimen of pomacentrid reef fish Dascyllus marginatus, Dascyllus aruanus, Chromis viridis, with two specimen of corals, Acropora sp. and Stylophora pistillata in two different areas. One area with a homogeneous distribution of coral, whereas the other area shows aggregated distribution. The most common fish was Dascyllus marginatus, Dascyllus aruanus was rarely found. A correlation between the size of the colony and the number of inhabiting fishes could be established. Larger colonies provide more shelter. There is a tendency that the more fine branched colonies of Acropora seemed to be more attractive to the observed fish species than Stylophora. Transects showed the proportional small habitat according to the examination area. Also a aggregated distribution of fish als well as coral colonies was shown.
The examination of competition behavior pronounces that D. marginatus shows more intraspecific competition whereas C. viridis shows more interspecific. Moreover Chromis viridis appeares in large shoals when observed. All three pomacentrid reef fish together in one colony was not found at all. D. marginatus together with C. viridis was the common documented species composition.

3.) TERRITORIES OF REEF FISH IN THE RED SEA (AQABA, JORDAN)
Axmann Paul, Domnanovich Alexander, Leitenberger Alexandra

Abstract
The task of our group was to examine the site specificity of different species of coral fish. Our observations focused on Heniochus intermedius, Heniochus diphreutes, Plectopomus pessuliferus marisrubri, Cephalopholis miniata, Pseudanthias squamipinnis, Synodus variegatus at two different coral sites. Different types of territorial behavior were distinguished:
Fish without territory or with very large territories
a) single
b) in pairs like Heniochus intermedius
c) in swarms like Heniochus diphreutes (adult)
Territorial fish
a) single, in meters to tens of meters distance to the block
b) swarm, only on one side of the rock (distance ranging up to 5 meters) like Pseudanthias squamipinnis, Heniochus diphreutes (juvenile)
c) single, close by the rock like Cephalopholis miniata, Plectopomus pessuliferus marisrubri
d) swarm, on coral structures
Our observations concentrated on Pseudanthias squamipinnis and Synodus variegatus.
The first is a swarm fish. The swarm is split into different sub-territories, each lead by a male individual and followed by several females (8-15). Synodus variegatus was encountered singly or in pairs. The median distance between individuals/pairs was 2.7 meters; the minimum distance between two individuals was one meter.

4.) COMMENSALISM BASED ON THE EXAMPLE OF PARUPENEUS SP. AND SCARUS SP.
Anna-Nele Herdina, Christian Lindle, Julia Lorber, Tina Plasil

ABSTRACT
Our task was to describe commensalism based on the example of the goatfish Parupeneus forsskali (Fam. Mullidae) and selected species of the family Scaridae (Parrotfish). We attempted to identify the different commensals and measure their participation time, behavior and distance to the host. All data were documented with a stop-watch, writing-board and pencil. Parupeneus forsskali: Their body is very well adapted to life on the ground. With one pair of barbels they dig holes whirling up a sand cloud whose volume depends on the size of the fish. The stimuli which initiate the interest of the commensals are the size of the sand cloud and the shape and pattern of the host. Commensals: The most common species seen together with P. forsskali are Bodianus anthioides (flee quickly, feed close to the host, sometimes more than one individual), Scolopsis gahnam (wait far away, sometimes hurry to the hole, when more than one host is present they partizipate on all sites, stay for a long time, intraspecific aggression), Cheilinus abudjubbe (farther away from the host than Sufflamen albicaudatus, sometimes more than one individual, follow over longer distances), Sufflamen albicaudatus (swim very close, sometimes dig actively in the sand, high intraspecific aggression, sometimes even interspecific aggression, follow over a long time and distance), Thalassoma klunzingeri (average distance is farther away than Sufflamen albicaudatus, they circle around the feeding group, very often more than one individual, they frequently change their position between the host and the reef), Torquigener flavimaculatus (sometimes close, sometimes farther away, only seen in the shallow area, mostly together with a group of small goatfish) and Coris caudimacula. P. forsskali is very often seen without commensals (even big individuals). Commensals generally prefer big hosts because of the larger sandcloud; this is why they sometimes switch from one host to another, bigger one. Sometimes the commensal stays with a goatfish for a long time and over greater distances but usually the fish just participate in the goatfish's feeding if they happen to be near one; when the host moves on, however, they typically remain in the area where they were before.
Fam. Scaridae: The most commonly observed species are Scarus gibbus, S. sordidus and S. niger. They arevery agile, they scrape algae from the coral blocks, and the feeding time is very short at one position. The commensals feed on broken-off fragments, usually without following the rapidly swimming host.
Commensals: Thalassoma klunzingeri (they are able to follow, sometimes even while maintaining body contact), T. lunare, Cheilinus abudjubbe, Ctenochaetus striatus, Centropyge multispinis, Sufflamen albicaudatus, Chaetodon paucifasciatus. graphically.