Lungfish Dominance Hierarchies

Cross references:    Lungfish  

The natural history of African lungfishes 
From The Biology and Evolution of Lungfishes.  See:  Lungfish     
I got the PDF through the library.   
from the Abstract
Remarkably little is known about the biology of the four Protopterus species, apart from certain detailed studies on their nesting behavior and estivating habits.
Three of the four species spawn in some form of seemingly constructed or prepared nest. The architecture of these nests shows marked inter- and intraspecific variability and is likely to be determined largely by various environmental factors. All three species show some type of parental care.
from the PDF
    "Taken in sum, the distribution of the four species extends across a large part of Africa. Two species, P. annectens (Owen) and P. dolloi Blgr are essentially west African taxa. The other two, P. aethiopicus Heckel and P. amphibius (Peters), are essentially east African."   
    "Male P. dolloi occupying nests during the dry season are not dormant and make frequent journeys into the vertical shaft in order to breathe at the surface of the water accumulated there. These fishes remain in the nests as the swamps refill with the next rains, and spawning takes place in the enlarged part of the gallery (see below). The use of a single nest for both estivation and breeding is apparently a unique feature of P. dolloi."   
    "During the dry season the nests are occupied only by males. Females leave the swamps as these begin to dry out and spend the dry season in the open water areas of Stanley Pool. It seems likely that small and presumably immature males also leave the drying swamps and spend the dry period in the same places as the females." 
    "The breeding nests of P. dolloi are the same structures used by adult males as dry-season refuges. The eggs are deposited in the cavelike chamber in the main tunnel; it is here too, that the greatest concentration of young is subsequently found, although older nestlings make frequent excursions into the vertical part of the nest in order to breathe air at the water surface." 
    "A parent fish was sometimes present in three of the four nests studied. In two of these the fish's sex could not be determined definitely, but judging from the size of the individuals and from their broad pectoral fins and broad snouts, both were probably males.  The adult in the third nest was a male. The fish (of undetermined sex) occupying the deep pit-like nest in the papyrus swamp guarded the young with vigor on some occasions, rising to the surface and snapping at any objects that fell or were introduced into the water, even attacking the observer's shadow when it fell across the surface."   
    "The occupation and defense of a nesting site can be considered as a display of territorality.  Curry-Lindahl's ('56) extensive field observations on P. aethiopicus in the Lake Edward region also suggest that some degree of territorality may be displayed outside the breeding season.  Adult male and female P. dolloi occupy different habitats during the dry season, the males staying in the dried out swamps and the females returning to the permanent waters from whence they return when the swamp areas are again flooded."   
My comment
Although no competitive interactions between males have been recorded, it is quite clear that, in at least some species, the males establish definite territories.  This strongly suggests, without actually proving, the presence of a male dominance hierarchy.   

The Natural History of the Australian Lungfish (Goog) 
Full length PDF available online for free. 
This is not the same as the book reference, above. 
It's not possible to copy-and-paste from the online PDF.  However, the copy-and-paste function works once the PDF is downloaded.     
from the Abstract
    "Aspects of the biology, phylogeny, distribution, appearance and adaptations to the environment of the Australian lungfish, Neoceratodus forsteri, are described.  Lungfish are long lived benthic omnivores, well adapted to an unaltered natural environment, which includes a stable water  level, flowing and still areas, and stands of submerged water plants (macrophytes) or roots along the bank to shelter the vulnerable eggs, embryos and hatchlings."    
from the PDF:   
Year after year, they spawn in the same places, on the same patches of submerged plant or in the same masses of algae or tree roots. This may reflect ownership of territories by specific males, a trait developed to a high degree by the African and South American lungfish (Kerr, 1950, Johnels and Svensson, 1954).
Two references
1.  Kerr, J. G. 1950. A Naturalist in the Gran Chacao. Cambridge: Cambridge Univ. Press. (Lepidosiren Expedition:169-229).   
2.  Johnels, A. G. and Svensson, G. S. O. 1954. On the biology of Protopterus annectens. Ark Zool. 7:131-164. 
My comment
Ownership of territories by specific males" is a typical aspect of male dominance hierarchies.  Unfortunately, neither of these references is available either through Google or the library.   

Spawning Behaviour in the Queensland Lungfish, Neoceratodus forsteri (Trove)   
Full length PDF available online for free. 
    "From an elevated rocky ledge six feet above the water we were easily able to view the fishes' activities with the aid of head torches, the light from which did not seem to disturb the fish. Gradually their movements became more restricted in range to a patch of weed about ten feet from the edge of the water. Swimming to and fro, over and through the weed, they gave the appearance of playing "follow the leader". During this time the second fish repeatedly nosed the cloacal region of the leader and was seen to "bump" it several times with its snout. This same fish was seen several times to take in its mouth a long strand of what appeared to be weed, and wave it about. Both fish were then observed from time to time to dive repeatedly through a localized area of weed, often disappearing from view for a few feet. During these "dives", one fish would follow the other closely and both were seen to shake their tails rapidly from side to side. On one occasion a third fish approached but one of the pair dashed at it, causing the intruder's rapid retreat."    
My comment
If both the "third fish (that) approached" and the "one of the pair (that) dashed at it" were both males, then this could be seen as an example of a male dominance hierarchy.  However, neither fish's gender is known.    

The Biology of Lungfishes (Goog) 
This is the Table of Contents of a 536 page book which I was able to obtain from the library. 
    Chapter 4. The General Natural History of the African Lungfishes -
Chrisestom M. Mlewa, John M. Green, Robert L. Dunbrack 

Abstract - Hi-Res PDF (325 KB) - PDF w/links (343 KB) 
transcribed from the Abstract
    "Males may become mature at a larger size than females, possibly because they must construct and defend nest sites, and provide care to eggs and young.  Female P. aethiopicus in lake populations only move to inshore spawning areas when ready to spawn and return to open waters soon after spawning ..." 

Australian Lungfish (Wiki) 
Full length article available online for free. 
Five spawning behaviours have been observed:
         5.  Should a third lungfish appraoach during the spawning a fifth behaviour has been observed - the interloper is driven off aggressively.