December 2003 - February 2004

Newsletter of the Shell Club of Sydney
NSW Branch, The Malacological Society of Australasia Limited ACN 067 894 848

Mature Cypraea tigris Northern NSW 2004 98.4mm
The shell colouring is quite dark, except for the three striking and unusual wavy yellow lines across the dorsum.
See below for more details of this and other melanistic tiger cowries observed at the same location

Northern NSW Shell Field Trip January 2004

Steve Dean (Sheller Editor)

For the last week of the school holidays three generations of Deans, Keith, Steve and Peter (age 11) went on a field trip to Northern NSW to look at a rock platforms. We went to a different platform each daytime low tide. Between low tides we filled in time with fishing, swimming and sight seeing. We stayed in my camper van, usually in camping grounds. All three of us are keen shell collectors, and the older two wanted to show Peter some of the spots where we collected when we were younger 30 - 40 years ago, and to see if the same sorts of shells were still present.

The good news is that even though we were there at the very end of the six week summer holiday period when all rock platforms had been picked over by others, shells were as abundant as they were 30 years ago. As in Sydney there are a lot more Turbo imperialis on the rock platforms than there used to be. We visited David Tarrant who reported that in the dead shell rubble area at Woolgoolga one teenage girl had collected over 30 cowries in good condition almost every day of her holiday there. David therefore took his children and us to a less known rubble area to look for washed in dead shells.

The water between Coffs Harbour Main Beach and its Island was too deep for the holidaymakers to wade out. However on the last day of the holidays, just before dusk, there was no waves or wind and a very low tide, so we braved it and waded out for a look for 30 minutes. In the middle of one large rock pool above high tide (water stays hot in this pool) there was a Tridacna squamosa (Clam) over 210mm in length:- attached to a rock and very visible in the middle of the pool 0.5m deep. I felt around it and it had no growths on it and quite large flutes on the ribs. (If anyone wants to view it I can provide details of the location of the pool where it is growing).

We saw one dead Nodopelagia brazieri at Woolgoolga, and as we headed north we observed many more live and dead, some with very dark colouring. When looking for shells different people are good at spotting different things. Pete spotted more than 80% of these, no mater how hard I tried to find them.

We saw a few species of cone, one of which I cannot identify. Once someone identifies it I will alter this web page. To help anyone who may be able to let me know what it is here are some comments: The step in the spire at the suture of the last whorl may just be unusual growth as sometimes happens with cones. The spiral lines are groves, otherwise the outer shell is smooth (no granulose bumps or spiral chords). There are also fine spiral brown coloured lines associated with these. There is no darkening at the anterior end, inside or out. The brown blotches between each shoulder turret are actually made up of several fine radiating lines running only the width of the turret at the shoulder. The dark band on the outer shell is actually colouration on the inside of the shell. (25.7mm)

The Conus Papiliferus below was also more elongated than its Sydney counterparts and had much straighter sides and sharper shoulder.

Keith and Pete were very pleased to observe Conus ebraeus both alive and dead. They have not spotted these before.

Sundials Heliacus variegates were still to be found living in the same pool on Sawtell Island where they have previously been observed.

At Angourie we found Natica gualtieriana in the sand. I have not seen these in NSW before.

The Nassarius glans particeps from Northern NSW has quite different patterning to the Sydney form. 
These wash up dead on the beaches in quantity at Woolgoolga, the same as in Sydney.

I have yet to identify the Nassarius species below (15.6mm). It is not particeps or spiratus.

This Nassarius conoidalis was in gem condition even though it had a hermit crab.

This Mitra aurantia was living on an exposed part of a rock platform amongst shell rubble and small shells with hermit crabs.

We saw several species of cowrie. On a rock platform near Yamba our best find was a colony of Cypraea tigris. They were fully mature, gem, and had extremely dark dorsums, one being almost completely black over the top of the dorsum. 

Photos of melanistic cowries do not show the pattern very well so I used a flash up close, which artificially lightened the pictures below but at least makes the patterns visible. I also included up to three conventional Queensland tiger cowries in some of the shots for colour and lightness comparison. As can be seen the flash makes them look pale as well.

All five Yamba specimens are white underneath per normal Cypraea tigris. On the dorsum the base colour is yellow. They then have a grey layer over most of this, and then very dark spots on top of that. This makes for interesting overall colouration. In the two pictures below the five dark shells are the Yamba cowries.

For purposes of the descriptions beolw the bottom five in this picture are numbered #1 to #5

Two of the five Yamba specimens pictured (#2 105.9mm and #5 94.5mm) are only slightly darker than some Great Barrier Reef tiger cowries although the colouring is different. However the other three Yamba shells are stunning specimens:

 

#3 from the group picture has a unique pattern of three yellow wavy stripes (front cover) This is caused by the grey layer running in 5 separate bands across the shell with the yellow showing through between, then the spots on top making the stripes look wavy. (The pictures below are lighter than the actual shell so you can see the grey bands)

#1 is quite large (104.9mm) and spectacularly dark all over (the picture cannot do justice to its rich golden brown colouring)

#4 is smaller (98.6mm) but is almost black over the top of the dorsum. 

TRIPHORIDAE - New South Wales

John Franklin

How many of us over the years have acquired minute shells where the aperture is located on the left-hand side?

Further, how many of us have put these sinistral shells in a box with a label describing the family name "Triphoroidea" and the locality but with no other distinguishing features? 

Once having acquired the shell the difficulty has been for the researcher/collector to differentiate between each species. Some reasons for this difficulty are that the shells are small, there is a large number of species and the difference between each shell is superficially slight. No doubt these problems are not new to minute shell research generally, but members of the Triphoridae family present the investigator with complexity.

In the historic background early researchers dealing with this family of shells from New South Wales such as Tenison-Woods 1876, Henn-Brazier 1894, Hedley 1903 and Laseron 1954 had little better than a large magnifying glass with which to identify species and allot them to their respective genus. In the early days it would have been almost impossible to determine protoconch characteristics.

It was to be many years later with the adoption of the scanning electron microscope/micrograph SEM that scientists have been able to make a more accurate determination of species.

In 1983 Marshall revised the family and defined a specific region of study, being south of Geraldton Western Australia and south of the New South Wales border with Queensland.

Marshall found that triphorid fauna distribution and larval development differ between east and west of Bass Strait. As between northern tropical and southern warm temperate faunas, species that are located in Queensland are rarely found in New South Wales. The fact that some Queensland species are located in New South Wales can be accounted for in the transportation of larvae by the south bound water masses.

In attempting to determine species particularly for this family and in general other minute shell families it is essential to look for the following shell characteristics:-

(i) colour pattern, shape, size, teleoconch, protoconch, operculum and radula;
(ii) it cannot be too strongly emphasised that the key to classification of triphorids is the study of the protoconch. Therefore worn, drilled or broken shells are almost useless for study.

In recent times there has been a rekindling of interest in triphorids from New South Wales, which has promoted further research. Such interest has been triggered by the relative frequency of species being available in shell sand, increasing knowledge and awareness of what to look for and the availability of sophisticated equipment as an aid in species determination. Clearly distribution analysis shows that triphorids exist almost the entire length of the New South Wales coastline from Eden to Tweed Heads.

A research monitoring program has now been developed and emanating from this program will be an increased knowledge of the numerous species that constitute the family, and a better understanding of the location/habitat of the taxa generally.

What follows are tables of the general characteristics of triphorids and a distribution analysis of those shells particularly in New South Wales but also including the other states of Australia.


References:
Allan, T., 1950 Australian shells, Georgian House, Melbourne at pp. 90-91
Laseron, C., 1954 Rec. Aust. mus., 3, pp. 139-158, figs. 1-30 and Laseron, 1958, Aust. J. Mar. Freshw. Res., 9, pp. 569-658, figs 1-255.
Iredale, T. and McMichael, D.F., 1962 A reference list of the marine mollusca of New South Wales, The Australian Museum Sydney at pp. 46-47.
Marshall, B.A., 1983 A revision of the recent Triphoridae of Southern Australia (mollusca: gastropoda) Records of the Australian Museum, Supplement 2, 119 pp.

Superfamily TRIPHOROIDEA
Family TRIPHORIDAE

Shell Characteristics
 

Superfamily TRIPHOROIDEA
Family TRIPHORIDAE

 DISTRIBUTION ANALYSIS