Table 4. — Groups formed from cluster analysis of species of fishes and decapod 

 Crustacea collected in the North and South Santee Rivers from 1975 and 1976. 

 Dendrograms are not shown. 



North Santee R. 



South Sanlee R. 



Group A 

 Lagodon rhomboides 

 Alpheus heterochaelis 

 Eucinostomus argenteus 



Group B 



Prionotus tribulus 

 Dasyatis sabina 

 Callinectes similis 

 Gobiesox strumosus 

 Etropus crossotas 

 Hypsoblennius hentzi 

 Xiphopenaens kroyeri 



Group C 

 Astroscopus y-graecum 

 Ancylopsetta quadrocellata 

 Ophidion marginatum 

 Urophycis floridana 

 Centropristis striata 

 Urophycis regia 

 Penaeus duorarum 



Group D 

 Arius felis 

 Pephlus alepidotus 

 Callinectes ornatus 

 Selene vomer 

 Port un us gibbesii 

 Pagurus longicarpus 

 Clibanarius vittatus 

 Opsanus tau 



Trachypenaeus constrictus 

 Menticirrhus americanus 



Group E 

 Alosa sapidissima 

 Paralichthys dentatus 

 Cynoscion nebulosus 

 Mugil cephalus 

 Dorosoma petenense 

 Gobionellus hastatus 

 Rhithropanopeus harrisii 

 Peprilus triacanthus 

 Anchoa hepsetus 

 Panopeus herbstii 

 Pomatomus saltatrix 

 Chioroscombrus chrysurus 



Group F 

 Lepisosteus osseus 

 Cyprinus carpio 

 Palaemonetes pugio 

 Alosa aestivalis 

 Ictalurus punctatus 

 Ictalurus furcatus 

 Macrobrachium ohione 

 Anguilla rostra ta 

 Morone saxalilis 



Group G 

 Ictalurus catus 

 Trinectes maculatus 

 Micropogonias undulalus 

 Anchoa mitchilli 

 Penaeus setiferus 

 Bairdiella chrysoura 

 Cynoscion regatis 

 Stellifer lanceolatus 

 Penaeus aztecus 

 Symphurus plagiusa 

 Callinectes sapidus 

 Paralichthys lethostigma 

 Brevoort'ia tyrannus 

 Leiostomus xanthurus 

 Palaemonetes vulgaris 



Group A 



Ophidion marginatum 



Ancylopsetta quadrocellata 



Urophycis regia 



Urophycis floridana 



Etropus crossotus 



Alosa sapidissima 



Cynoscion nebulosus 



Archosargus probatocephalus 



Lutjanus griseus 



Lagodon rhomboides 

 Group B 



Dasyatis sabina 



Citharichihys spilopterus 



Caranx hippos 



Eucinostomus sp. 



Centropristis philadelphica 

 Group C 



Hypsoblennius lonthas 



Trachypenaeus constrictus 



Menticirrhus americanus 



Clibanarius vittatus 



Hypsoblennius hentzi 



Penaeus duorarum 



Centropristis striata 



Opsanus tau 



Symphurus plagiusa 



Gobiesox strumosus 



Paralichthys dentatus 

 Group D 



Pomatomus saltatrix 



Peprilus triacanthus 



Anchoa hepsetus 



Chioroscombrus chrysurus 



Panopeus herbstii 

 Group E 



Cynoscion regal is 



Penaeus aztecus 



Stellifer lanceolatus 



Callinectes similis 



Peprilus alepidotus 



Selene vomer 



Lepisosteus osseus 



Rhithropanopeus harrisii 



Macrobrachium ohione 

 Group F 



Ictalurus punctatus 



Ictalurus furcatus 



Alosa aestivalis 

 Group G 



Anchoa mitchilli 



Bairdiella chrysoura 



Callinectes sapidus 



Penaeus setiferus 



Paralichthys lethostigma 



Brevoortia tyrannus 



Leiostomus xanthurus 



Micropogonias undulalus 



Trinectes maculatus 



Ictalurus catus 



Palaemonetes vulgaris 



Palaemonetes pugio 



Dorosoma petenense 



The classification based on the quantitative similarities of 

 distribution of species found in the North and South Santee 

 Rivers produced the species groups shown in Table 4. In order to 

 determine affinity of species assemblages along the estuarine 

 gradient, we compared species group constancy and fidelity 

 among the eight stations occupied in the North and South 

 Santee Rivers during 1975 and 1976 (Fig. 3). This was deemed 

 preferable to comparing site groups determined by cluster 

 analysis with species groups because site groups broadly 

 overlapped and were not clearly separated by cluster analysis ac- 

 cording to salinity regimes within the estuary. 



In the North Santee River, one species group (G) was con- 

 sistently encountered at stations NS01 and NS04, with slight 

 decline in constancy at NS07 and NS11 (Fig. 3). Species in this 

 group were not restricted in their distribution to any station 

 location but were ubiquitous over the sites sampled, which is an 

 indication of their apparent euryhalinity. The other species 

 groups were not consistently collected at any of the stations, as 

 indicated by low constancy. Species group B, which is largely- 

 composed of coastal marine fishes, was entirely restricted to sta- 

 tion NS01, which suggests the stenohaline nature and transient 

 occurrences of these fishes within the estuary. Other groups (A 

 and D) were also apparently composed of marine species which 

 were not able to penetrate far into the estuary. Group E species 

 were associated with intermediate to higher salinities and did not 



32- 



North 



Santee 











28- 















24- 















20- 















16- 







i 









12- 







."'' ' 















i 



,\ 







>- 4- 



H 





\''\c- 



i 

 i 



_ i 



/ 



i-\ 



_ V - " \ _ 





III! 



1 1 ! 1 1 



1 1 



1 1 



i i i i 



1 1 1 1 1 1 1 



1 i i I r~i i— i — i i i i i i — n — i — tt — i i i i — r 



JFMAMJJASONDJFMAMJJASOND 



1975 



1976 



Figure 3. — Two-way coincidence tables of constancy and fidelity which compare 

 species associations with stations in the North and South Santee Rivers, 1975-76. 

 The species associations, designated alphabetically, resulted from cluster analysis of 

 species (dendrogram not shown) collected from the Santee system. Species compris- 

 ing these associations are listed in Table 5. 



